Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

4th year > Sheep > Flashcards

Sheep Flashcards

1
Q

Timing for pregnancy, lactation and dry months in sheep?

A

Pregnancy: 5 months (Sept/Oct is tupping time)
Lactation: 4 months (March is lambing time)
Dry: 3 months (June/July is weaning, lamb produced July-Dec)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What makes up Pedigree, hill and lowland flocks?

A

Pedigree - pure bred hill/upland/lowland for own replacement or to sell, terminal sires
Hill - pure bred females, cross breeding females to sell (cross with leicester breeds), males for meat
Lowland - ewes often cross bred, mated with terminal sires, produce fat lambs for sale/meat
Store lambs - buy fattening lambs and finish for meat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Characteristics of sheep hill breeds?

A 
Hardy
Good mothering
One lamb/ewe
Male offspring for meat
Females kept as replacements or sold to upland farms to be crossed with long wool  breeds - border or blue faced leicester
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Characteristics of sheep upland breeds (long wool)?

A 
Bigger carcass
Fast growth
Prolificacy
Female hill sheep crossed with male long hair breed
Blue face X = mile
Border X = half bred
Females sold to lowland farms as ewe replacements
Males sold for meat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Characteristics of sheep lowland farms?

A 
Buy in mules or half bred ewe replacements
Or breed their own
Cross with terminal sire breeds
All lambs for meat
Keep ewes for 4 crops of lambs then cull
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the problems with the UK sheep stratification structure?

A

Little genetic improvement in UK flocks
Breeding based on size and appearance rather than economically valuable traits
About intensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ideal sheep characteristics?

A

Lamb vigour
Good mothering
Growth rates
Resistance to disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How to use Estimated Breeding Values (EBVs)?

A

Halve the value for the offspring
Weight EBV +6 = genetic potential to be 6kg heavier (3kg for offspring)
Litter size is percentage more lambs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Gross and net margin equations? (sheep)

A

Gross margin = output - (variable costs + replacement costs)

Net margin = gross margin - fixed costs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the targets for: ewe mortality, ewe culling rate, ewe:tup ratio, replacement rate,lamb mortality scanning to birth, lamb mortality birth to turn out (1 week old), lamb mortality turn out to sale, lamb mortality overall birth to sale, lamb growth rate?

A 
Ewe mortality: 1-3%
Ewe culling rate: <30%
Ewe:tup: 40:1
Replacement rate: 20-25%
Lamb mortality scanning to birth: 6%
Lamb mortality birth to turnout: 6%
Lamb mortality turnout to sale: 2%
Lamb mortality overall birth to sale: 8%
Lamb growth rate: 0.2-0.25kg/day
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Condition score targets for upland, lowland and hill sheep at tupping, mid pregnancy, lambing and weaning?

A

Tupping -> mid pregnancy -> lambing -> weaning
Upland: 3 -> 2.5 ->2.5 -> 2
Lowland: 3.5 -> 3 -> 3 -> 2.5
Hill: 2.5 -> 2 -> 2 -> 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is flushing? What are the static and dynamic effects?

A

Increase feed to ewes pre-tupping to increase BCS by 0.5 to improve number of eggs produced
Usually with grass management
May need supplementary concentrates
Static effect = ewes in better BCS have higher ovulation rate
Dynamic effect = increasing live weight gain gives higher ovulation rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why should the BCS be maintained/reduce by 0.5 around mid-pregnancy?

A

Placenta develops

If underfed = small placenta = low lamb birth weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When does most of sheep foetal growth occur? Why is it difficult to feed ewes more towards lambing?

A

70% in last 5 weeks

Ewe’s rumen capacity is decreasing due to foetus size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What to feed sheep in late pregnancy? How?

A

Supplementary feeding usually required for last 6-8 weeks
If later lambing (April/May) may only need well managed grass
Monitor BCS and/or metabolic profiles (3 weeks before lambing)
Feed in groups - 1.2m squared per ewe, 50/pen, group by scan/BCS/lambing date
Good access to top quality forage is key - hay/silage ad lib
Max 1kg concentrate/day, 0.5kg/feed
Water!
Consider vitamins and minerals
Trough space - ad lib forage 15-20cm/ewe, concentrates 45-60cm/ewe
Best to feed 1/3 of ewes ad lib forage at once, concentrates all at once
Pen first time ambers separately
Consider floor feeding concentrates
TMR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are common problems with sheep nutrition?

A 
Thin
Broken mouth
Old
Concurrent disease - worms, lameness etc
Poor quality forage - acidic, mouldy, wet, low feed value
Overcrowding
Inadequate quantity
Inadequate trough space
Acidosis - max 0.5kg/feed
No access to water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Problems with fat ewes in pregnancy?

A 
More prone to pregnancy toxaemia
More dystocia
More likely to prolapse
Large foetuses can cause dystocia
Oversized lambs have higher mortality
Fat is expense to put on
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

3 main problems if lack of/poor quality colostrum for lambs?

A

Hypothermia
Starvation
Infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When do lambs start eating grass and when weaned

A

Start eating grass at 6 weeks old

Weaned at 12-16 weeks (some evidence better if 6-8 weeks?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is pregnancy toxaemia? Risk factors?

A 
= under-nutrition/energy deficiency/hypoglycaemia/hyperketonaemia
Thin
Fat (don't eat enough)
Stress
Late pregnancy
Broken mouth
Often fatal unless treated early
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Clinical signs and diagnosis of pregnancy toxaemia?

A 
Separate from group
Inappetent
Apparent blindness
Tremors of face and ears
Progress to recumbency
Dead foetuses
Death
0-10 days
Diagnosis: clinical signs and BOHB > 3mmol/l
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How to treat pregnancy toxaemia of sheep? And if not improving?

A

Early! To prevent hypoglycaemic brain damage
Separate
Give highly palatable feed - fresh food and water
IV glucose
50-100ml 40% dextrose - can repeat after couple of hours
Propylene glycol - 50ml twice daily (max 2-3 days)
If late/not improving:
- PTS
- Abort ewe after 135d pregnancy with 16mg dexamethasone
- C section only if ewe viable, otherwise PTS
- poor prognosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Flock prevention of pregnancy toxaemia?

A

Ensure adequate feeding
BCS 6-8 weeks before lambing
Feed according to number of foetuses/BCS
Monitor ketone body levels 2-3 weeks before lambing
Cull broken mouth ewes
Avoid sudden changes/stress in last 6 weeks of pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When is hypocalcaemia seen in sheep pregnancy? Risk factors?

A

Usually pre-lambing 6 weeks onwards (not always)
Often stress induced - handling, gathering for vaccinations etc
Changes of diet/pasture/snow/water deprivation
Acidosis with cereal diet
Older ewes
Rapid growing lush pasture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Clinical signs of hypocalcaemia in sheep?

A 
Initial weakness and excitement
Progresses to recumbency
Dilated pupils
Constipated
Bloated
Collapsed
Flaccid paralysis
Comatose -> death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Treatment for hypocalcaemia in sheep?

A

Slow IV 40-80ml 20% calcium boroglucoronate or very slow 20-40ml 40% - rapid response
SC 1ml/kg 20% CaBG (50-100ml) warm - slow response
Monitor as may relapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

History and clinical signs for hypomagnesaemia (staggers) in sheep?

A

History: post lambing/peak lactation, lush grass/bare pasture
Rapid onset
Sudden death usually
Neurological signs - excitable, tremors, recumbent, hyperaesthesia, convulsions, death/found dead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Treatment for hypomagnesaemia (staggers) in sheep?

A

IV 40-80ml 20% Calcium

SC 50-80ml 25% MgSO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Differential diagnoses of sick/recumbent ewes at lambing time?

A 
Hypocalcaemia
Hypomagnesaemia
Pregnancy toxaemia
Listeria
Mastitis 
Metritis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What drugs to use for dystocia in sheep?

A

NSAIDs
Epidurals
Antibiotics
Give lamb colostrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

When is a simple embryotomy done for sheep? How?

A

Dead lambs which are not possible to deliver per vaginum
Lots of lube
Remove forearms - cut through skin around leg above carpus, then up towards elbow, undermine attachment of shoulder to chest wall, pull leg off
Repeat other if necessary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Indications for a sheep caesarean? Contraindications?

A 
Over sized lambs
Ringwomb (failure of cervix to dilate)
Vaginal prolapse
Foetal monster
Malpresentation

Contra: rotten lamb/smelly fluids unless can exteriorise uterus (embryotomy or euthanasia best)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Drugs for sheep caesarean section? Local methods?

A

Broad spectrum antibiotics (5 day coverage)
NSAID
Local anaesthetic - local infiltration (40ml total), inverted L block or paravertebral T13, L1, L2, L3, 5ml procaine/site), sacra-coccygeal epidural (with xylazine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Method of sheep caesarean?

A

Incise half was between last rib and wing of ileum, 10-15cm below transverse processes
15cm incision
Skin and SC tissue with scissors
External and internal abdominal oblique, then lift transverse and peritoneum before incising (so don’t puncture rumen)
Grasp uterine horn and exteriorise
Incise 10-12cm with scissors
Remove lamb
Check for other - reach into other horn, can make another incision if needed
Suture uterus with continuous inverting pattern - catgut, clean, can do 2 layers
Peritoneum and transverse, then internal and external abdominal obliques with continuous simple catgut
Skin - ford interlocking, simple interrupted or other, nylon
Blue/yellow spray
Can give sheep oxytocin after to involute uterus and protect the sutures (1-2ml)
Feed lambs!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Risk factors for metritis in sheep?

A

dystocia - poor hygiene, dead lambs

Post abortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Clinical signs of metritis in sheep?

A

Dull, recumbent, depressed
Toxaemia - congested mucous membranes
Red/brown or purulent vaginal discharge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Treatment of metritis in sheep? Prevention?

A

Antibiotics and NSAIDs
Poor prognosis
Prevent with hygiene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

When is vaginal prolapse usually seen in sheep? Problems with it?

A

Common in last 4 weeks of pregnancy (1-2%)
Vagina or vagina and cervix, may include bladder
Inflamed swollen infected tissues, obstruction of bladder, urine retention
Can be fatal if untreated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Suggested causes of vaginal prolapse in sheep?

A 
Prolific breeds > hill breeds
Litter size
Age
Obesity
Hypocalcaemia
35-40% will re-prolapse
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Treatment for vaginal prolapse of sheep pre-lambing? And cervix post lambing? Prevention?

A

Retention devices - discomfort, irritation of mucosa, secondary infection
Harnesses - avoid pressure sores
NSAIDs
Long acting antibiotics
Surgery
Cervix post-lambing - same and mark for culling
Prevention - difficult as cause uncertain, cull as increased risk, put harness on before occurs next lambing, review poss risk factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Procedure for vaginal prolapse surgery of sheep?

A

Epidural anaesthetic - reduce straining, analgesia, sacra-coccygeal or first intercoccygeal space, procaine (short action) or procaine and xylazine (24h+)
NSAIDs and antibiotics
Clean and assess - mild chlorhexidine
Replace prolapse - gently with palm of hand, raise back end of ewe
Suture with obstetrical tape, purse string (leave 1.5cm opening, burner
Mark ewe, remove sutures before lambing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is a complication of vaginal prolapses in sheep? What to do?

A

Rectal prolapse
Epidural, replace, purse string suture
Tissue non viable - amputate rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Treatment of uterine prolapses after lambing?

A 
Epidural
Clean
Remove or trim placenta
Replace carefully and fully evert
Suture
Oxytocin
Antibiotics
NSAIDs
Calcium?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Impact of mastitis in sheep?

A

Ewe mortality
Ewe premature culling
Lamb mortality
Lamb poor growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Most common 2 causes of mastitis in sheep in the UK? How are they transmitted?

A

Staph aureus - via teat skin

Mannheimia haemolytica - via lamb’s mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Udder and milk clinical signs of peracute/acute/chronic/subclinical mastitis in sheep?

A

Peracute - cold blue +/- necrotic in gangrenous mastitis
Acute - hot, red, painful, swollen
Chronic - udder may be light with hard swellings (abscesses)
Subclinical - abnormal milk appearance (clots) and composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Systemic clinical signs of mastitis in sheep?

A 
Toxaemia - congested mucous membranes?
Pyrexia
Tachycardia
Rumenal stasis
Lameness
Recumbency
Hungry lambs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Risk factors for mastitis in sheep?

A

Nutrition - undernutrition in late pregnancy/lactation, low BCS, vitamin E/selenium deficiency
Concurrent disease - fluke, jones, worms, dystocia etc
Prolificacy - multiple lambs
Older ewes
Udder conformation - abnormal teat position
Udder abscesses
Teat lesions - orf, over-suckling, chilling (chapped teats)
Genetics
Hygiene
Milking practices (dairy sheep)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Treatment of mastitis in sheep?

A

No real evidence basis
Gangrenous - euthanasia (v poor prognosis)
Acute - systemic antibiotics (ideally based on c+s, first line amoxicillin for 5 days, tilmicosin licensed), strip udder to remove toxins, NSAIDs, IV fluids, supportive care
Chronic - cull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

7 mastitis prevention points in sheep?

A
  1. Ensure adequate ewe nutrition pre and post lambing
  2. Wean lambs at 12-16 weeks abruptly
  3. Control orf
  4. Control concurrent disease e.g. fluke, worms
  5. Don’t turn out ewes with triplets
  6. Cull ewes over 7/with broken mouth/udder lumps/abnormal teat positions
  7. Ensure good bedding and hygiene in sheds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

When is the sheep breeding season?

A

August - December

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is the difference between spring and christmas lamb management?

A

Spring - easy management, essential for hill and upland (limited housing, later grass growth)
Christmas - intensive management (housing essential), better lamb prices at easter market

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is responsible for the seasonality of sheep breeding?

A

The pineal gland
Tryptophan –> serotonin –> melatonin
Melatonin only secreted during hours of darkness
Hypothalamus is sensitive to melatonin during the late afternoon
Coincidence of hypothalamic sensitivity and melatonin = short day breeders
Oestrogen negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How many follicular waves do sheep have?

A

2-5
50% have 4
35% have 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

How long should a ram remain with ewes for natural service? Why?

A

At least 35 days
Ewes ovulate and are receptive to the ram every 16-18 days
So allows for ewes that didn’t conceive when first mated to be bred again at next heat
Can saddle the ram to see mated ewes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How is AI done in sheep and why? When?

A

Laparoscopy due to cervical anatomy

12-24 hours after oestrus detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is the ‘ram effect’?

A

Introduction of a ‘novel’ male or after 2+ weeks of male absence
Induces cyclicity earlier in the season
Can synchronise cycling sheep to some extent
2 peaks of oestrus activity after male introduction
First ovulation ‘silent’ for some
19 days first ovulation for others
25 days second ovulation for those who had silent ovulation
Use vasectomised ram so cannot fertilise
Breeding males then later introduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How can sheep breeding seasonality be manipulated with melatonin?

A

Melatonin implant at base of ear

  • Suffolk/Cross - use from mid May to late June to introduce ram in late June/July
  • Mules/halfbreds - use from early June to late July to introduce ram from mid July to late August
  • Day 1: 30 weeks before want to lamb - move ewes from sight/smell/sound of rams
  • Day 7: Implant ewes
  • Day 42: 30-40 days after implantation - introduce rams
  • Delay of 14-21 days before mating, peaks at 25-35 days
  • Use vasectomised ram for first 14 days to get more compact lambing period
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How can sheep breeding seasonality be manipulated with progesterone sponges?

A

Chronogest = synthetic progesterone in a sponge, place intavaginally for 12-14d to get into bloodstream
Combine with PMSG (FSH activity) injections at time of sponge removal to stimulate cyclicity out of season
Oestrus 36-72 hours after sponge removal
1 ram:10 ewes
Ram in 48 hours after sponge out (not earlier)
Lamb in 3 week period, most in 7 days
Also CIDR now licensed (real progesterone so can measure?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How can sheep breeding seasonality be manipulated with prostaglandin?

A

Can use to cause luteolysis and induce oestrus in cycling animals
Not authorised but can use half of cattle dose
CL refractory to PG for 2-4 days
Oestrus in about 40 hours
2 PG injections 7-11 days apart induces 95% of ewes in 72 hours
Some data suggests lower pregnancy rates than progestergens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How can lambing be induced if service date known?

A

8ml Dexamethasone injection from day 140 after ram in
Lamb about 40 hours later
Not authorised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What BCS should rams be before breeding? How long does sperm take to develop?

A

BCS 3.5

60+ days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Sheep gestation length?

A

145 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How many times maintenance should ewes be fed at conception-42days/42-90days/90days?

A

Conception-42 days: maintenance only
42-90 days: maintenance + 2MJ/day (grass/forage)
90days-parturiton: good nutrition needed for rapid foetal growth/colostrum quality and quantity/prevention of metabolic diseases, feed according to single/twin/multiple, should be 2xmaintenance by lambing time (but reduced appetite in last 2 weeks due to rumen space)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What to make sure to do when vasectomising a ram?

A

Store the epididymis

Identify the animal (ear tag)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What should the scrotal measurement be of a ram?

A

30cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Causes of epididymitis in rams? Prevention?

A 
Actinobacillus seminis
Haemophilus somnus
Histophilus ovis
Treatment unsuccessful!
Prevent by growing rams in small groups, graze and rotate to clean paddocks
May develop to orchiditis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Physical problems with testicles which may reduce fertility?

A

Cryptorchidism (rig) - uni or bilateral, need lower temp for sperm to develop, don’t put with too many ewes if unilateral
Testicular degeneration - bilateral unless specific local injury
Testicular hypoplasia - uni or bilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What causes scrotal mange of rams? Clinical signs? Diagnosis? Treatment?

A

Chorioptes bovis - sheep adapted strain
Crusty scabs on lower 1/3 of scrotum
Crake and expose sore, weeping dermis
Sore as get ‘gratification reflex’ when handled
Can occur on lower legs and poll
If extensive then raises blood flow and testes temperature –> testicular degeneration and reduced sperm quality
Confirm with skin scrapes from several locations
Doramectin and diazinon sheep dip effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is pizzle rot (balanoposthitis)?

A

Affects rams and wethers - castrations affect development of area so urinate inside prepuce
Ranges from small ulcers and discharge at prepuce to scanning?? causing blockage of the prepuce and fly strike
Corynebacterium renale - also associated with off
Produces ammonia from urea in urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Pizzle rot risk factors, prevention and treatment?

A

High protein concentrates and lush grass = risk factors
Access to water, salt or ammonium chloride to increase drinking and acidify urine
Isolate animals to reduce environmental contamination
Clip wool away and clean area
Systemic antibiotics and fly treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

When do 49% of lambs die? :(

A

At lambing (0-48h)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What are the main causes of lamb mortality/morbidity?

A 
Pre-partum - abortion/still birth
Intra-partum: dystocia:
- Birth trauma
- Ruptured liver
- Fractured ribs
- Brain haemorrhage
- Anoxia
Post partum:
- Hypothermia
- Starvation
- Infection (e.g. watery mouth, salmonella, cryptosporidium, septicaemia, meningitis, joint ill, clostridial disease)
- Predation
- Accidents
- Congenital defects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Risk factors for lamb mortality?

A 
Maternal factors - genotype 'mothering ability', experience, ewe health, nutrition, stress, ewe health
Prenatal infections
Lamb birth weight - genetics, nutrition 
Dystocia
Colostrum/milk
Hygiene - pens, lambing, equipment, navel dipping
Shepherds - experience, number 
Weather
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Problems from no colostrum?

A

Inadequate immune system
No energy
Die of hypothermia, starvation or infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

How much colostrum does a lamb need? How to check? When to supplement?

A

50ml/kg in first 6 hours (200ml)
200ml/kg in first 24 hours (1L)
Check - full belly, ewe has colostrum, watch for suckling
Supplement if needed - triplets, orphans, thin ewes, dystocia, weak lambs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the ideal and minimum plasma protein level of lambs from colostrum?

A

Ideal > 60g/L
Minimum > 45g/L
Suckling from ewe is best!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Risk factors for poor colostrum intake?

A 
Concurrent disease - dystocia, lameness
Undernutrition of ewe
Breeding - mothering, lamb vigour
Age of ewes
Multiple births
Lambing environment - stress, mis mothering, shepherding skills, poor weather
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Colostrum substitute options?

A

Ewe colostrum - can use oxytocin to assist milking out single ewes
Goat colostrum is good - similar energy, good Ab spectrum, but CAE negative herds
Cow colostrum - 2 hours of calving, jones and TB negative, vaccinated for clostridia, less energy so need 30% more
Commercial colostrum - variable quality, often good energy and protein but poss less Ig, often dried cow colostrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Protocol for feeding orphan lambs?

A 
50ml/kg colostrum in first 6 hours
Total 250ml/kg in first 24 hours
Week 1 - 300ml milk (warm) 3-4 x daily
Week 2 - 1-1.25L twice daily
Hay and creep feed from week 1
Wean 4-6 weeks at 15kg
0.4m squared/lamb
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

When is hypothermia of lambs usually seen?

A

Early lambing flocks/outdoor lambing
Usually in first 6 hours
Can use brown fat for 6 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Normal rectal temperature for lambs?

A

39-40C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Risk factors for hypothermia of lambs?

A 
Bad weather
Weak
Premature
Triplets
Dystocia
Infection
Poor ewe nutrition
Mis mothering
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What to be careful to avoid when warming/giving colostrum to lambs?

A

Warming a hypoglycaemic lamb without giving glucose first will cause a hypoglycaemic fit
Oral administration of fluids to hypothermic lambs can cause regurgitation and inhalation pneumonia or asphyxia
So need I/P glucose!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

How to treat a lamb with hypothermia <37C? And clinical signs?

A 
Will be severely weak, depressed, arched back, stands close to dam, recumbent
Dry
I/P 20% glucose 10ml/kg
Warm to 37C
Colostrum 50ml/kg 
Warm to 39C
Return to ewe
Monitor
Shelter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

How to treat a lamb with hypothermia 37-39C? And clinical signs?

A 
Moderately weak but can still suckle and hold head up
Dry
Feed warmed colostrum
Check ewe's milk status/health
Return to ewe
Provide shelter
Supervise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

How to do intra-peritoneal glucose injections for lambs?

A

Strength is 20%
10ml/kg warm
Use 19G 1’’ needle
Hold lamb by front legs
Just below and to one side of navel
Warm in box with fan heater under wire mesh
When lamb is conscious and able to suck, feed 150-200ml colostrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Prevention of lamb hypothermia?

A

Breeding - breed from good mothers, hardy vigorous lambs
Ewe nutriton - lamb birth weight, brown fat, colostrum
Provide shelter
Identify at risk lambs and give special attention
Lamb coats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What causes watery mouth in lambs? Clinical signs?

A

E.coli - lack of colostrum or delay allows gram negative bacteria to multiply unchallenged, bacteriaemia, bacterial death releases endotoxins, lamb dies of endotoxaemia
Within first 3d of birth
Depressed, profuse salivation, swollen abdomen, collapse, dehydration, death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Risk factors for watery mouth in lambs?

A 
High litter size
Low birthweight 
Early castration
Inadequate colostrum
Poor hygiene
Later in lambing period
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Treatment for watery mouth in lambs?

A

Oral fluids - 50ml/kg every 6 hours
NSAIDs - anti-endotoxic effects
Broad spectrum antibiotics - amoxicillin/clavulonic acid, spectinomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Prevention of watery mouth?

A

Nutrition/BCS of pregnant ewes
Colostrum - check, policies
Hygiene of environment
Don’t castrate until >24h (as would sit around for few hours as painful)
Check/monitor sensitivity
Metaphylactic oral antibiotics - spectinomycin in outbreak scenarios

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Policy for antibiotic use for watery mouth?

A

Targeted oral antibiotics for prevention of WMD may be appropriate if:

  • Lambs born into groups where there ave been previously recent clinical cases
  • Triplets or low birth weight lambs born into challenging environmental conditions or towards end of lambing period

But whole flock treatment of all lambs at birth should be avoided

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Causes of lamb neonatal diarrhoea?

A 
Lamb dysentery - Clostridium perfringens
E.coli 
Rotavirus
Cryptosporidium parvum
Salmonellosis (typhimurium or dublin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What agents cause joint ill (infectious arthritis) in lambs in the UK?

A

Streptococcus dysgalactiae
Erysipelothrix rhusiopathie
Tick pyaemia (Staph aureus)
Anaplasma phagocytophila?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Sources of infection for Strep dysgalactiae causing joint ill in lambs?

A

Unknown?
Theory:
- Low carriage rate in ewes (milk, report tract?, faeces)
- Direct contamination of her lambs and indirect to other lambs
- Contaminated lambing environment (bedding, equipment etc)
- Builds up through lambing
Route of infection unsure - oral? milk? faecal? bedding? respiratory? cutaneous has good evidence - exposed surfaces such as umbilicus and wounds (docking and castration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

How old are lambs affected by Strep dysgalactiae joint ill? Clinical signs?

A

<4wo
Mild or no pyrexia
Moderate to severe lameness
Single joint (50% of cases) or 2 or 4
Paresis, intra-vertebral joints affected
Carpal, hock, fetlock, stifle most common
Joints swollen, hot and painful
Progress to chronic thickened joints, restricted movement, poor growth
Radiographically thickening of joint capsule, osteophytic changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Treatment of Strep dysgalactiae joint ill of lambs? (also for meningitis)

A

No evidence base for treatment or control
5 day course early in disease - suggested repeat once if required, euthanise if not better
Penicillin drug of choice - not sensitive to tetracyclines
NSAIDs
Dexamethasone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Prevention/control of Strep dysgalactiae joint ill in lambs? (also for navel ill and meningitis)

A

Move all ewes and lambs away from contaminated environment
Hygiene - turnout to pasture, clean+disinfect sheds and pens between ewes, remove placentas and afterbirths, re-bedding frequently, wear gloves when lambing, wash hands between lambing, disinfect all equipment between lambs
Ensure colostrum intake
Navel dipping in 10% iodine by 15mins old and repeat 2-4h later
Metaphylactic treatment of neonatal lambs in outbreaks but don’t continue in successive years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

How old are lambs affected by Erysipelothrix rhusiopathie joint ill? Clinical signs?

A

6 weeks - 6 months old
Polyarthritis (fibrinous), pyrexia, lameness, stiffness
High morbidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

What type of organism is Erysipelothrix rhusiopathie? How is it spread to cause joint ill in lambs?

A

Ubiquitous
Commensal and pathogen
Faces, urine, saliva, nasal secretions, carrier animals, wild birds
Environmental contamination
Skin wounds - surgical castration and docking sites, umbilicus?
Post dipping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Treatment and control for Erysipelothrix rhusiopathie joint ill in lambs?

A

Penicillin daily for 5 days
NSAIDs
Control - clean, dry lambing environment, hygiene of wounds and navels, vaccination licensed for pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Clinical signs of navel ill/omphalophlebitis in lambs?

A 
Hunched back
Poor body condition
Poor suckling
Moist, swollen, painful navel
Pus from navel
Spreads to joints
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

Treatment for navel ill/omphalophlebitis in lambs?

A

Poor prognosis
Broad spectrum antibiotics for at least 5-7d (penicillin etc)
Prevention same as joint ill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

What causes meningitis in lambs and what are the clinical signs?

A

Opportunistic bacteria, inadequate colostrum
Weak, depressed, collapsed, fitting
Congestion of blood vessels around the eyes
Prognosis poor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Clinical signs of drunken lamb syndrome? Age affected?

A

1-3 weeks old
Acute ataxia and uncoordinated tendency to recumbency
Death quickly follows usually within 24-48 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Diagnosis of drunken lamb syndrome?

A

Clinical signs and lab confirmation
Biochemically lambs may be weakly azotaemic and hyperphosphataemic
All have metabolic acidosis due to excess D-lactate (due to colonic fermentation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Treatment of drunken lamb syndrome?

A

Sodium bicarbonate dissolved in tap water orally with parenteral long acting amoxicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

How to treat entropion in lambs?

A

Treat early - check at birth

Flip out lid, sub-conjunctival injection with penicillin, staples

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

How to treat atresia ani in lambs?

A 
Use small amount of local
Incise skin where anus should be
Identify and open blind rectum
Evacuate
Suture rectal wall to skin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

How to treat prolapsed intestines in lambs?

A 
Gaseous GA
Surgically repair
Clean intestines with sterile fluid
Enlarge hole
Replace
Suture defect
Good aftercare
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

Clinical signs of patent urachus in lambs and treatment?

A

Umbilicus swollen (ddx hernia/abscess)
Dribbling urine (ddx urolithiasis)
Surgery under GA to locate
Usually need antibiotics as infection common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

What is swayback in lambs? When is it seen?

A

Copper deficiency

When ewes deficient in pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Clinical signs of swayback in lambs?

A

Still births
Weak lambs
Characteristic weakness of pelvic limbs
Delayed form in offer lambs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Which sheep breed is prone to swayback?

A

Scottish blackface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

Treatment for swayback?

A

Copper injections/boluses/capsules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

When is iodine deficiency seen in sheep/lambs? Clinical signs?

A

Ewes grazing pasture or crops with high goitrogens
Newborn lambs - hypothermia, starvation, pot bellied, weakness, death
Thyroid gland goitre in lambs
Late abortion
PM: goitre gland:bodyweight ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

Prevention of iodine deficiency in lambs?

A

Treat ewes with potassium iodide 4 weeks pre-lambing or boluses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

How much should 1 day old single/twin/triplet lambs weigh?

A

Single: 5.5-7kg
Twin: 5-6kg
Triplet: >4kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

What indicated dystocia on lamb PM?

A 
Swollen head/tongue
Meconium staining
Oedema of head and shoulders
Fractured limbs and ribs
Free blood in carcass
Haemorrhages 
Hepatic rupture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

What indicates hypothermia/starvation on lamb PM?

A

No brown fat

No milk in abomasum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

How to monitor weight of growing lambs?

A 
EID and electronic scales, or traditional weigh scales and paper
Pick typical group of lambs (known age)
Assume 4kg birth weight
8 week weight - 300-500g/day
Weaning weight - 300-500g/day
Sale weight - 200-250g/day
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

Causes for individual/few lambs with poor growth?

A 
Low birth weight
Border disease
Congenital problem
Neonatal/chronic infection
Inadequate milk - triplets, too little milk, bottle fed, weaned too early
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

Causes for poor growth in a group of lambs?

A 
Inadequate nutrition
Parasitic disease - esp anthelmintic resistance
Trace element deficiencies
Pneumonoa
Lameness - joint ill, CODD, FR/scald
Off, scab
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Differentials for lambs with diarrhoea?

A 
E.coli
Salmonella
Clostridium perfringens type B (lamb dysentery)
Clostridium perfringens type D (pulpy kidney)
Cryptosporidium parvum
Coccidiosis
Nematodirus battus
Parasitic gastroenteritis
Acidosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

When is Cryptosporidium parvum diarrhoea seen in lambs/calves? Clinical signs?

A 
Severe outbreaks at end of lambing/calving
Intensive systems
Lambs 3-7d old
Profuse diarrhoea (blood)
Dehydration
Can be fatal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

Diagnosis of C parvum in lambs?

A

Stain faecal smear C parvum
PM histopathology (definitive)
Check for E.coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

Treatment and prevention of Cryptosporidium parvum in lambs?

A

Supportive treatment - house, oral fluids (50ml/kg 4-6xdaily)
No drugs licensed
Prevention - use different fields/housing for lambing and calving, move to fresh pasture in outbreak, put newborn animals to clean pasture, improve indoor hygiene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

Which Coccidia species affect lambs? How infected?

A

Eimeria crandalis/ovinoidalis
Non disease causing strains normally in sheep
Source is from ewes or older lambs multiplying

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

Risk factors for Coccidia in lambs?

A 
High stocking rates
Inadequate colostrum
Mixing ages
Stress
Concurrent Nematodirus infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

Clinical signs of Coccidia in lambs? Age affected?

A 
4-8 weeks old
Diarrhoea (can be haemorrhagic)
Tenesmus
Fever
Weight loss
Death
Subclinical - poor growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

Diagnosis and treatment of Coccidia in lambs?

A

Faecal samples for coccidia count - not speciation to determine if pathogenic strain
House sick animals
Oral fluids (50ml/kg 4-6xdaily)
Diclurazil, toltrazuril - usually group problem so treat metaphylactically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Prevention of Coccidia in lambs?

A

Reduce risk factors:
Hygiene of pens and feed troughs
Stocking rates
Colostrum intake
Nutrition
Batch rearing - avoid grazing younger and older lambs together
Consider prophylactic/metaphylactic treatment at risk times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

When is acidosis of lambs seen? What happens?

A

Consumption of rapidly fermentable carbohydrates - e.g. sudden introduction of ad lib carbohydrates
Stubble grain crops, wheat and barley
Fall in rumen pH
Lactic acid production
Rumenitis
Metabolic acidosis
Lead liver abscessation, fungal rumenitis and death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

Clinical signs of acidosis in lambs?

A 
Sudden death
Dull, depressed
Reluctant to move
Teeth grinding
Colic, bloat
Ataxia, recumbent
Dehydration
No rumen sounds
Diarrhoea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Diagnosis of acidosis in lambs?

A

History and clinical signs
Rumenocentesis pH <5.5
Rumen liquor no live organisms
PM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

Treatment of acidosis in lambs?

A 
IV fluids - isotonic saline plus bicarbonate
Oral fluids by stomach tube
Multivitamins
Penicillin daily for 10 days
Hay
Review feeding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

Causes of rumen bloat in lambs? Clinical signs?

A

Uncommon in sheep
Grain, oesophageal obstruction, legumes (frothy bloat)
Left side distension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

Differentials to rumen bloat in lambs?

A 
Hypocalcaemia
Abdominal catastrophes
Peritonitis
Ascites
Uroperitoneum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

Treatment of rumen bloat in lambs?

A

Stomach tube
Simeticone
Consider rumen trochar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

Clinical signs of lamb nephrosis syndrome? Age affected?

A

2-12 weeks old
Older lambs (>4 weeks) tend to lose condition and have diarrhoea
Stand around water troughs or field drains due to increased thirst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

Diagnosis and treatment for lamb nephrosis syndrome?

A

Raised urea and creatinine, hyperkalaemia
Decreased albumin:globulin ratio
Metabolic acidosis
No treatment found to be effective - tend to waste away and die within a week so euthanasia preferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

Why is cobalt important for sheep?

A

For red cell development, amino acid synthesis, energy metabolism - constitute of vitamin B12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

Clinical signs of cobalt deficiency ill thrift in lambs?

A 
Weight loss
Anaemia
Slow growth
Debility
Watery eye discharge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

Treatment of cobalt deficiency in lambs?

A

Cobalt rumen boluses/oral drenches
Vitamin B12 injections
Cobalt in creep feed
Pasture treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

Clinical signs of selenium deficiency in sheep?

A

White muscle disease - ill thrift lambs, weakness, collapse, lame
Poor reproductive performance of ewes

147
Q

Which sheep breeds are more prone to copper poisoning?

A

North Ronaldsy
Suffolk
Blue faced Leicester
Texels

148
Q

Difference between acute and chronic copper poisoning?

A

Acute - ingestion of large amounts
Chronic - ingestion over long time period, stored in lysosomes in liver, capacity suddenly released into circulation, may be precipitated by stress, intravascular haemolysis and jaundice

149
Q

Clinical signs of copper poisoning in sheep?

A 
Ataxia
Head pressing
Jaundice
Recumbency
Death
150
Q

Treatment of copper poisoning in sheep?

A

Sodium calcium EDTA
Supportive therapy
Remove feed source
Molybedenum and sulphur added to water

151
Q

What causes ‘Pneumonic Pasteurellosis’ in sheep? Where does it come from?

A

Mannheimia haemolytica
Present in nasopharynx of healthy sheep - disease when enters lung
Often secondary to other disease/stress

152
Q

Clinical signs of Pneumonic Pasteurellosis in sheep?

A

Pyrexia
Mucopurulent nasal discharge
Cough
Death

153
Q

Treatment for Pneumonic Pasteurellosis in sheep?

A

Oxytetracycline/amoxixillin/macrolides - 5-7d
Avoid stress
Consider metaphylactic treatment of groups at risk or treat when signs appear
Prevention vaccine - heptavac P

154
Q

Which Mycoplasma species can cause pneumonia in sheep? Clinical signs?

A

Mycoplasma ovipneumoniae

Cough, slight nasal discharge

155
Q

Diagnosis, treatment and prevention of Mycoplasma pneumonia in sheep?

A

Diagnosis - history, clinical signs, BAL, PM
Treatment - oxytet long acting
Prevention - ventilation, stocking rates, hygiene

156
Q

Which bacteria can cause chronic suppurative pneumonia (lung abscesses) in sheep? Clinical signs?

A

T pyogenes
Usually 1-2 in group
Secondary to pasteurellosis infection/inhalation pneumonia
Chronic weight loss, pyrexia, soft cough, increased resp effort, nasal discharge?
Poor prognosis

157
Q

Which lungworm species are there in sheep? Clinical signs? Diagnosis? Treatment?

A

Dictyocaulus filaria
Muellerius capillaris - not thought to be significant
Coughing, dyspnoea
Baermann test - larvae in faeces
Treatment - anthelmintics, antibiotics, NSAIDs, supportive

158
Q

What defines drug resistance?

A

<95% efficacy

159
Q

How resistant are current anthelmintics?

A

BZs: 80% of farms have resistant strains
Levamisole: 47% have resistant strains
MLs: 30% have resistant strains

160
Q

How do nematodes cause disease?

A

Damage gut lining - reduces absorption
Remove nutrients
Remove blood (Haemonchus)
Host immune response

161
Q

When are Teladorsagia, Trichostrongylus and Haemonchus seen in sheep?

A

Teladorsagia - peaks early summer
Trichostrongylus - late summer/autumn
Haemonchus - doesn’t survive well over winter but produces lots of eggs (10,000/day/worm) - mid spring-late autumn serious outbreaks

162
Q

Nematodirus epidemiology?

A

Lamb to next year’s lambs
Most hatching and release occurs during period of chill, followed by 10-18C (some don’t require chill anymore so causes disease in autumn)
Large numbers of L3 hatch simultaneously
Severe outbreaks of diarrhoea typically 6-12 week old lambs in late spring/early summer
Clinical signs caused by invading L4 - can have disease but no eggs in faeces

163
Q

Difference between type 1 and 2 Teladorsagia disease?

A

Type 1 - lambs first grazing season, mid summer onwards

Type 2 - yearlings in winter months, emergence of hypobiotic larvae

164
Q

Which nematode causes ‘black scour’ in sheep?

A

Trichostrongylus

165
Q

What clinical signs does Haemonchus cause in sheep?

A 
Acute regenerative anaemia
Chronic hypoproteinaemia
Bottle jaw
Weakness, collapse
Tachycardia
Sudden death
166
Q

Clinical signs of Nematodirus in sheep?

A

Very acute severe diarrhoea

Can have high mortality

167
Q

When do sheep begin to gain immunity to nematodes? What does this depend on?

A 
5-6 months old
Must have been exposed
Nutrition
Genetics
Stage of production - peri-parturient immunosuppression 2-4 weeks pre-lambing until 6-8 weeks after
168
Q

What are the methods of action of BZs, MLs, Levamisole, amino-acetonitrile and spiroindoles?

A

BZs: tubular binding, prevents glucose uptake, ovicidal
Imidathiazoles (Levamisole): ganglion blocking, paralysis
MLs: blocks Cl- and GABA channels, paralysis
Amino-acetonitrile (monopantel): ACTH receptors, paralysis
Spiroindoles (e.g. derquantel): nicotinic cholinergic paralysis

169
Q

What are BZs effective for in sheep?

A

Broad spectrum round worms
Tape worms - but not clinically significant in sheep
N battus
Some hypobiosed larvae
Fluke (Albendazole)
But has most resistance - strong probability won’t work

170
Q

What are MLs effective for in sheep?

A

Round worms and mites

All injectable forms active against mange mites

171
Q

When should group 4 and 5 new generation anthelmintics be used?

A

Don’t keep for best

Use regularly as part of worm control plan, especially as quarantine dose

172
Q

What are the main causes for the development of anthelmintic resistance?

A 
Treating everything
Treatment frequency
Over use
Underdosing
Biosecurity
173
Q

How is a FEC reduction test done?

A 
10 lambs per group
4 groups - control, BZ, LM, Ivermectin
Weigh and mark
Pre-treatment FEC
Accurate dose of drug
7-14d post-treatment FEC
Calculate mean reduction in WEC
Should be >95%
174
Q

Why don’t dose and move?

A

Would just populate clean pasture with resistant strains so return to contaminated pasture

175
Q

How to do anthelmintic quarantine strategy?

A

For all bought in sheep
Dose with monopantel or derquantel and abamectin
Plus moxidectin or doramectin to treat scab
Hold off pasture for 24-48h
Return to contaminated pasture

176
Q

When to dose sheep with anthelmintics?

A

At lambing - leave at least 10% untreated
Tupping time - only if thin
Lambs - targeted to weight/FEC/use forecast/clinical signs/Famancha test

177
Q

What test is used for Haemonchus in sheep?

A

Famancha test

Uses pallor of eye mucous membranes

178
Q

Method of collecting samples for FEC of sheep?

A

Group - same age/repro status/field/AH treatments
Gather loosely in corner of field for 5-10 mins
Collect fresh dung (at least 10 samples)
Keep separate and cool - reach lab in 48h
Some labs accept pooled samples

179
Q

What tapeworms can sheep get? What are the final and intermediate hosts? Clinical significance for sheep?

A

Monezia expansa: soft mite -> sheep - uncertain pathogenicity
Taenia hydatigena: cysticercus tenucollis in sheep -> dog - liver damage, condemnation at slaughter
Taenia ovis: cysticercus ovis in sheep -> dog - cysts cause muscle damage and condemnation at slaughter
Taenia multiceps: coenuris cerebralis in sheep -> dog - neurological disease
Echinococcus granulosus: hydatid cysts in sheep -> dog - cysts in liver and lungs, condemnation at slaughter, zoonotic

180
Q

Which tapeworms are known as the thin necked bladder worm, sheep bladder worm and did worm?

A

Thin necked bladder worm = Taenia hydatigena
Sheep bladder worm = Taenia ovis
Gid worm = Taenia multiceps

181
Q

How to control tapeworms in sheep?

A

BZs for Monezia expansa in sheep
Surgical removal of Taenia multiceps cysts in sheep
Praziquantel every 6 weeks for dogs for all Taenia and Echinococcus granulosus
Don’t allow dogs to stray onto pasture
Don’t allow dog access to sheep carcasses

182
Q

How many sheep flocks are affected by scald/footrot in the UK?

A

97%

183
Q

What is scald? How is footrot graded? When seen?

A

Scald = interdigital dermatitis = benign footrot = footrot grade 1
Footrot grades 2-4 (progression of scald)
Scald is most common cause of lameness in sheep
Occurs when wet underfoot

184
Q

What causes scald and footrot?

A

Dichelobacter nodosus = main pathogen

Fusobacterium necrophorum found in some cases (=polymicrobial)

185
Q

Clinical signs of scald?

A 
Red/pink inflamed interdigital skin
Discharge (white/grey pasty 'scum')
Lame
No horn under-running
No foul smell
186
Q

What does the progression of scald to footrot depend on?

A

Virulence and dose of D nodosus
Susceptibility go the sheep
Whether the sheep is treated promptly before separation of hoof horn occurs

187
Q

Clinical signs of footrot? Infection reservoir?

A

Progressive under-running of sole of hoof horn, starting at medial aspect of sole and progressing laterally
Grey necrotic pungent smelling horn
Extremely painful -> rapid weight loss (reduced feed intake)
Lameness
Death from starvation and thirst in some cases
Infection reservoir = infected foot (direct/indirect contact transmission)

188
Q

Characteristics of Dichelobacter nodosus?

A

Facultative anaerobe
Survives in environment for 7 days
Present in normal sheep feet
Not flagellated
Fastidious gram negative anaerobe
Pathogenesis:
- produces extracellular proteases = key for virulence
- has fimbriae conferring motility and adherence
- fimbrial proteins = highly immunogenic (basis of serotyping)
10 major serotypes: A-I and M

189
Q

Characteristics of Fusobacterium necrophorum?

A

Anaerobe

Gut, faeces, widespread in environment

190
Q

Risk factors for footrot and scald?

A 
Warm
Wet underfoot conditions
Muddy
Housing
Gathering
Genetics - heritable susceptibility
191
Q

Treatment for scald?

A

Topical treatment:
-Oxytet spray - make sure dry before return to grazing
-Footbathing: formalin 3% max, zinc sulphate - must be exposed to infected interdigital area for 2 mins, clean feet beforehand, need correct conc and depth, dry standing on concrete after, repeat after 5-7d if necessary
Systemic:
-LA oxytet - usually not necessary

192
Q

Diagnosis and treatment for footrot? Control?

A

Diagnosis based on clinical signs (culture based diagnosis not routine as fastidious)
Treat asap!
Isolate lame sheep
Treat individuals/groups
Injectable long acting ABs best - LA oxytet cure rate 70-80%, may need to repeat until clinical cure
Footbathing: formalin, copper sulphate
DO NOT TRIM FEET!

Control:

  • footbathing
  • vaccination: based on fibril proteins
  • biosecurity, isolation and selection for resistance (culling?)
193
Q

What percentage of UK farms have CODD? At what prevalence?

A

35-50% of farms

0-50% prevalence on farms

194
Q

CODD clinical appearance and grades?

A

Ulcerative or proliferative lesion starting at coronary band
Progressive under-running of hoof wall downwards
Frequently results in sloughing of entire foot horn capsule
Very painful
Grade 1 - coronary band lesion only
Grade 2 - <50% horn capsule separated
Grade 3 - 50-100% hoof capsule off
Grade 4 - healing but still active lesion present
Grade 5 - healed

195
Q

What causes the most severe lameness in sheep?

A

CODD

Extensive damage to foot even down to bone

196
Q

CODD aetiology?

A

Treponemes strongly associated - T.medium-like/phagedenis-like/pedis
D nodosus and F necrophorum also found but unknown role

197
Q

Risk factors for CODD?

A

Seasonal trend late summer/early autumn
Large flock size
Lowland pasture, lush pasture, poached pasture
Sheep with footrot
Dairy cattle in close proximity
Bought in sheep
Ruminant GI tract, direct contact and foot trimming equipment = infection reservoirs

198
Q

CODD diagnosis and treatment? Control?

A 
Diagnosis normally visual (lameness and lesion score)
Responds to antibiotics
LA amoxicillin 71% cure rate
Often require repeated injections
Macrolides licensed in sheep
Formalin/copper sulphate footbaths 
Topical tetracycline

Control:

  • no vaccine and host immunity not protective
  • regular footbathing
  • improve farm hygiene
  • don’t trim infectious sheep lesions
  • flock biosecurity: purchase from known sources/health status, isolate lame sheep
199
Q

What is the 5 point plan for lameness in sheep?

A
  1. Vaccinate twice yearly - footvax
  2. Treat lame sheep quickly
  3. Biosecurity
  4. Environmental challenge
  5. Cull chronically lame sheep
200
Q

What is footvax? How well does it work? How to use? When?

A

Footrot vaccine - treats and prevents
70-100% cure rates
60-100% protection rates
May also have small protection against CODD
Multivalent vaccine containing multiple D nodosus strains
Oily adjuvants - site lumps
Don’t use prior to shearing or lambing
Don’t give treated sheep moxidectin 1%
Initial vaccination - 2 doses 5-6 weeks apart
6 monthly booster at risk periods - post scanning (housing) and post shearing in summer

201
Q

How long to isolate a sheep with footrot/CODD?

A

3-4 weeks

202
Q

When to cull lame sheep?

A

After 2-3 cases of lameness

203
Q

What is white line disease? What can develop?

A

No infection just separation of sole from wall - can carefully pare out area of separation
Doesn’t cause lameness unless sensitive tissue affected - impaction with stones, mud etc
Can develop abscesses - heat, pain, swelling, may burst out at coronary band, pare out if necessary to release pus

204
Q

Treatment for sheep toe granuloma?

A

IV regional anaesthesia
Cut back granulation tissue
Cauterise with disbudding iron to stop bleeding and ensure granuloma removed

205
Q

When are pedal joint abscesses seen? Treatment?

A

Consequence of white line abscess
Flush and antibiotics?
PTS
Digit amputation?

206
Q

How to do a sheep digit amputation?

A 
Sedation - xylazine
IV regional anaesthesia or ring block around foot - procaine
Clip, clean and prepare foot
Antibiotics, NSAIDs
Disarticulate between P1 and P2
Bandage foot
Change after 3-4 days
207
Q

What is the problem with trimming lame sheep feet?

A

Delays healing
May spread disease to hands and clippers
Studies showed treating alone with antibiotics better - foot shape will return to normal by self
So trimming and topical treatment not recommended for footrot

208
Q

What to do with overgrown sheep feet e.g. after housing?

A 
Likely to self correct
Only careful cosmetic trim
Don't over trim - causes granulomas
Don't cause bleeding
Don't trim if infectious foot lameness!
209
Q

What can cause post dipping lameness in sheep? What happens?

A 
Erysipelothrix rhusiopathie
Number of sheep 1 week post dipping
Lame, swelling above coronary band
Then progresses to other joints
Prompt treatment with penicillin
Clean dipper tank
210
Q

Clinical signs of strawberry footrot in sheep? What causes it? Treatment?

A

Proliferative scab lesions of distal limbs
Orf dermatophilus
Topical antibiotics and move to dry fields

211
Q

Types of arthritis in sheep?

A

Infectious arthritis - neonatal (strep dysglactiae), tick pyaemia (staph aureus), E rhusiopathie
Non infectious arthritis - degenerative joint disease, elbows of adult sheep, unknown aetiology

212
Q

What type of virus is orf? Clinical signs? Consequences?

A 
Parapox virus - zoonotic
Vesicular/proliferative scabby lesions - mouth/head and teats
Lambs but can affect ewes esp teats
4-6 week duration
Painful
- Interferes with suckling/eating
- Teat lesions - predisposes to mastitis
- Poor growth 
- Death
213
Q

How is orf spread?

A

Spread by contact
Damage to skin and mouth allows virus in - rough grazing/feed esp thistles
Virus doesn’t survive over winter outside but scabs remain infective for long periods in dry conditions

214
Q

Control of orf?

A

Isolate clinical cases - disinfect feeding bottles etc
Thorough cleaning and disinfection - steam cleaning (heat sensitive), trigene
No treatment - antibiotics for secondary infection
Vaccine only for infected farms (live and can cause disease, vaccine scabs are infectious, don’t use indoors as will contaminate housing)

215
Q

What causes sheep scab? Transmission?

A

Psoroptes ovis - allergic reaction

Spread by direct contact or infected scab fomites material on fence posts etc

216
Q

Clinical signs of sheep scab?

A

Kicking, scratching
Wool loss, ragged fleece, moist yellow appearance
Flank/dorsum/whole sheep
Progressively distressed, stop eating, weight loss, seizures, death

217
Q

Sheep scab diagnosis?

A

Choose itchiest sheep with wool loss
Edge of exudative lesions - wool pluck (seal in bag), skin scrape (put in container)
Warm sample
If negative sample again
ELISA - detects early stages, good se and sp

218
Q

Sheep scab treatment?

A

Must consider re-infection as survive off host 17-19 days
Must treat all sheep
Dexamethasone for severely affected sheep
Improvement in 2 weeks
Organosulphate dip - must do correctly to be effective, 1 minute in dip, do not use showers
Ivermectin - 2 doses 7 days apart, must move to clean grazing after first dose
Doramectin - 1 dose, must move to clean grazing after first dose
Moxidectin 1% - 2 doses 10 days apart, don’t need to move, don’t use if had footvax
Moxidectin 2% - 1 dose, don’t need to move, difficult to administer

219
Q

Sheep scab prevention?

A

Biosecurity
Observation not enough as 7-8 weeks before see clinical signs
Treat all bought in sheep
Double fencing
Disinfection of vehicles and equipment esp shearers and scanners

220
Q

How does Chorioptes bovis affect sheep? Diagnosis and treatment?

A

Ventral abdomen, scrotum
Pruritis, infertility
Skin scrape
Organophosphate dips

221
Q

Bovicola ovis? - Appearance? Favourable environment? Clinical signs? Problems? Diagnosis? Treatment?

A 
Small pale red brown louse
Highly host specific (sheep)
Permanent parasite
Spread by direct contact
Chew at skin and coat - feed on skin debris and wool
Like warm dark environment, not wet
Shearing and rainfall reduces risk
Pruritis, fleece loss
Hypersensitivity and irritation
Part fleece on back and flanks and look for clumps of lice
Treat worst affected
Synthetic pyrethroid pour ons - resistance concerns
Plunge dip, diazinon, OP dip
222
Q

How can scrapie affect sheep skin?

A

Usually neurological but can present as primary skin disease
Pruritis
Notifiable

223
Q

When is fly strike seen in sheep? Cause?

A

May to October
Lucilia sericata - lay eggs in fleece, larvae hatch 12h later, proteolytic enzymes and mouth hooks
Damage skinAttract other flies

224
Q

Clinical signs of fly strike in sheep?

A 
Wounds
Separate
Depressed
Foot lesions
Toxaemia
Death
225
Q

Risk factors for fly strike in sheep?

A 
Temperature - eggs need 10C to develop
Humidity >65% - rainfall
Shearing and fleece length
Faecal soiling - lush grass/worms, tail docking
Carcasses on farm
226
Q

Treatment of fly strike in sheep?

A

Early is best
Kill maggots - synthetic pyrethroid pour ons, deltamethrin
Clean woundsSupportive - antibiotics, NSAIDs, fluids
House
Address risk factors

227
Q

Where does Staph aureus usually affect the skin in sheep? Transmission? Treatment?

A

Peri-orbital eczema
Spread by contact, feeding troughs
Course of penicillin injections

228
Q

What does Dermatophilus congolensis cause in sheep? Clinical signs? Treatment?

A 
'Lumpy wool'
Associated with wet conditions esp after shearing
Thin wooled breeds
Crusty lesions with wool loss
Pruritic 
Risk for fly strike 
Treat with penicillin 3-5 days
229
Q

What causes caseous lymphadenitis in sheep? Treatment? Spread?

A

Corynebacterium pseudotuberculosis
Affects lymph nodes, esp parotid
Abscesses - antibiotics can’t penetrate so no effective treatment
Spread by close contact, fomites (shearing), resp spread (mediastinal LN abscessed rupture into airway)

230
Q

Control of caseous lymphadenitis in sheep?

A

Infected flock: Test and cull affected (culture, ELISA), hygiene of shearing, vaccination
Biosecurity - disease monitoring schemes, isolate and test bought in sheep

231
Q

Which plant can cause photosensitisation of sheep?

A

St John’s wort

232
Q

Causes of abnormal wool fibres?

A

Border disease - hairy shakers

Copper deficiency of growing lambs

233
Q

What causes tick borne fever in sheep? Clinical signs?

A

Anaplasma phagocytophila
Seen in tick areas upland
Profound immunosuppression:
- secondary infections
- fever: spermatogenesis infertility of rams, abortion of ewes
- Predisposed to other diseases
Do become immune
Bought in animals and new lambs most susceptible (no previous exposure)
Control:
- treat with sheep pyrethroid pour ons before entering tick area
- avoid introducing naive sheep when pregnant or at tupping time

234
Q

What causes tick pyaemia in lambs? Clinical signs?

A

Staph aureus
Polyarthritis/joint ill
Immunosuppression
Spinal abscesses/joint abscesses

235
Q

What causes louping ill of sheep? Clinical signs? Prevention?

A

Flavivirus transmitted by ticks
Non suppurative meningoencephomyelitis
Varying severity - incoordination to seizures and death
Variable signs - head pressing, trembling/tremors, nystagmus, lip twitching, ‘louping gait’
Most infections are slight and give immunity
Often young stock bought in - immunologically naive
Protective immunity in colostrum, vaccine, tick control, grazing management
Zoonotic

236
Q

Causes of a low scanning % in a flock?

A

Season
Infectious infertility - toxoplasma, border disease
Ewe - BCS, age, disease
Ram - age, disease, number, fertility

237
Q

What sheep health schemes are there by the Scottish Rural University College?

A

Maedi visna (MV)/Caprine Arthritis Encephalitis (CAE) accreditation scheme
Enzootic abortion of ewes (EAE) accreditation
Scrapie genotyping
Scrapie monitoring sheme
Caseous lymphadenitis (CLA)
Johne’s risk assessment

238
Q

Causes of sudden death of neonatal lambs?

A 
Birth trauma (rib fractures, dystocia)
Starvation
Hypothermia
Clostridial disease - lamb dysentery, tetanus
Meningitis
Septicaemia
Diarrhoea
Watery mouth
Intestinal torsion
Predators
239
Q

When to sample lambs to check colostrum Ab transfer?

A

2-7do

240
Q

Causes of sudden death in growing lambs?

A

Clostridial disease - pulpy kidney, brassy, abomasitis, tetanus
Pasteurellosis - B trehalosi, M haemolytica
Urolithiasis
Parasitic gastroenteritis
Fluke
Rumen acidosis
Plant poisoning

241
Q

Causes of sudden death in adult sheep?

A

Metabolic disease - hypocalcaemia/magnesaemia
Parasites - fluke, Haemonchus
Plant poisoning - rhododendron, yew, laurel, acorns
Pasteurellosis
Toxaemia - mastitis, metritis
Clostridial disease - struck, blackleg, black’s disease, tetanus

242
Q

When does plant poisoning of sheep usually occur? Which plants? Clinical signs?

A

Usually when lack of other food available - starvation, snow etc
Yew, acorn, laurel, rhododendron, laburnum
Sudden death, severe abdominal pain, neurological signs

243
Q

Which agent causes systemic pasteurellosis in lambs? Clinical signs? Risk factors?

A 
Bibersteinia trehalosi
Normal inhabitant of URT
Sudden death 6-12mo lambs
Change of grazing, weather, concurrent disease
Stress of handling/gathering may worsen
244
Q

What do most clostridial diseases cause? What does it do to cause disease?

A

Sudden death

Organisms multiply rapidly and produce toxins

245
Q

Trigger factors for clostridial diseases of sheep?

A

Changes in environment
Injury/trauma/insult
Endoparasites
Poor hygiene

246
Q

What type of bacteria are Clostridia? How are they grouped?

A 
Anaerobic gram positive rods
Grouped by organ systems:
- Enterotoxaemia
- Parenchymatous organs (liver and kidney)
- Myonecrosis and toxaemia
- Neurotropic
247
Q

Which clostridial disease cause what?

A

C perfringens
-B: lamb dysentery (enterotoxaemia)
-C: struck (enterotoxaemia)
-D: pulpy kidney (nephrotoxic)
C novyi
-A: big head (rams head wounds, myonecrosis and toxaemia)
-B: black’s disease (hepatotoxic)
-D: bacillary haemoglobinuria (hepato and nephrotoxic)
C septicum
-Braxy (enterotoxaemia)
-Malignant oedema (myonecrosis and toxaemia)
C sordelli - abomasitis
C chauvoei - blackleg (myonecrosis and toxaemia)
C botulinum C - botulism (neurotrophic)
C tetani - tetanus (neurotrophic)

248
Q

Risk factors and prevention for Clostridial diseases?

A

Enterotoxaemic and parenchymatous groups: dietary change and fittest animals - prevent with vaccination and avoid sudden diet changes
Myonecrosis and toxaemia: contamination of wounds (lambing, castration/tail docking/injections/fighting wounds) - prevent with vaccination and good hygiene

249
Q

How do sheep get botulism? Clinical signs?

A

Pasture contaminated with poultry manure

Flaccid paralysis and death

250
Q

How do sheep get tetanus? Clinical signs?

A

Contamination of docking and castration wounds
Spastic paralysis, stiffness, recumbency
Often not sudden death

251
Q

What causes lamb dysentery? When is it seen? Risk factors? Clinical signs?

A 
C perfringens type B
Lambs <3 weeks olf
Often fit lambs
Overcrowding, hygiene
Severe abdominal pain, dysentery, sudden death
252
Q

What causes pulpy kidney disease? When seen? Clinical sign?

A 
C perfringens type D
Most common clostridial disease
4-10 weeks old or finishing lambs 6 months plus
Sudden death
May see ataxia, opisthotonus
253
Q

What causes clostridial abomastitis and toxaemia? Risk factor? Clinical signs?

A 
Clostridium sordelli
4-10 weeks old
Intensively housed creep fed lambs
Sudden death
Or bloat due to displaced distended abomasum
254
Q

When to vaccinate against Clostridia in sheep?

A

4 weeks before lambing to also protect lamb via colostrum

Then lambs from 3 weeks

255
Q

What causes anthrax? What does it cause in sheep?

A

Bacillus anthracis
Sudden death
Rare in sheep but don’t rule out
Notifiable

256
Q

Clinical signs of FMD in sheep?

A

Lameness
Blisters on tongue
Fever
Not usually fatal (but economic impact)

257
Q

How is bluetongue spread? Mortality rate? Clinical signs?

A 
Culicoides imicola
Up to 70% mortality
Fever
Swelling of head and neck
Lameness
Mouth ulceration
Drooling
Haemorrhages of skin
Respiratory probelms
258
Q

What are prion diseases? Spread?

A

Causes abnormal protein to accumulate in brain causing neurological dysfunction
Spreads mother to offspring prenatally and via colostrum and milk
And also horizontally via birth fluids, placenta

259
Q

Clinical signs of scrapie? Incubation period

A 
Progressive, fatal neurological disease
Long incubation period: 2-5 years
Single animals
Altered mental state
Excitable, nervous, depressed, aggressive
Tremors, ataxia, recumbency
Pruritis, rubbing, scratching
Weight loss
Death
260
Q

Clinical signs of diffuse cerebrum being affected in sheep?

A

Altered mental state - depressed, hyper excitable, disorientated
Blindness
Seizures
Opisthotonus - recumbent, extended front legs, flexed hind legs

261
Q

Examples of conditions affecting diffuse cerebrum in sheep?

A

Bacterial meningitis
Cerebrocortical necrosis
Pregnancy toxaemia

262
Q

Clinical signs of local cerebrum being affected in sheep?

A

Contralateral blindness
Circling
Proprioceptive deficits

263
Q

Examples of conditions affecting local cerebrum in sheep?

A

GID cysts (Coenuris cerebrally, Taenia multiceps)
Brain abscesses
Trauma

264
Q

Clinical signs of cerebellum being affected in sheep?

A 
Altered head carriage
Balance - ataxia not weakness, wide-based stance
Dysmetria - high stepping
Intention tremor
Nystagmus
265
Q

Examples of conditions affecting the cerebellum in sheep?

A

Not common
Congenital - cerebellar hypoplasia
Border disease hairy shaker - cerebellar hypoplasia
Poss abscess (rare)

266
Q

Clinical signs of the vestibular disease in sheep?

A 
Head tilt to affected side
Loss of balance
Circling
Falling/rolling to one side
Horizontal nystagmus
Aural discharge
Can get facial paralysis
267
Q

Examples of conditions affecting the vestibular system in sheep?

A

Middle ear infection

Unilateral facial nerve paralysis - runs close to middle ear

268
Q

Clinical signs of the brainstem being affected in sheep?

A 
Depression (because of ARAS)
Multiple cranial nerve deficits due to brainstem nuclei - esp V, VII, VIII,
Ipsilateral hemiparesis (motor tracts passing through)
269
Q

What key condition affects the brainstem in sheep?

A

Listeriosis

270
Q

Clinical signs of conditions affecting the spinal cord in sheep?

A 
No signs of central disease
Depends on site of spinal cord
Tetra/paraparesis
Proprioceptive deficits
Skin sensation
Pain
Pedal and other spinal reflexes
271
Q

Examples of conditions affecting the spinal cord in sheep?

A

Spinal abscess - joint ill tick pyaemia
Wobblers syndrome - texels
Trauma
Congenital abnormality

272
Q

Common neurological problems in young lambs 0-3mo? Main signs?

A

Border disease (tremors, hairy shakers)
Congenital swayback (ataxia) - copper deficiency
Drunken lamb syndrome (ataxia, depression)
Lamb nephrosis (ataxia, depression)
Bacterial meningitis (collapsed)
Tetanus
Trauma accident
Spinal abscess (joint ill)
Listeriosis - circling, facial nerve paralysis
Louping ill

273
Q

Treatment of spinal abscess from joint ill SD in lambs?

A

1mg/kg dexamethasone

Penicillin for 5 days at least

274
Q

Common neurological problems of lambs over 3mo?

A 
Cerebro-cortical necrosis (CCN)
Listeriosis
Gid
Louping ill (tick area)
Trauma accident
275
Q

What causes cerebro-cortical necrosis (CCN) in lambs? When affected?

A

Vitamin B1 deficiency (thiamine)
Acute onset in growing lambs (6-12mo)
Sporadic but can get outbreaks
History of diet change or worming

276
Q

Clinical signs of cerebro-cortical necrosis (CCN) in lambs?

A 
Vary depending on progression of disease
Dull
Disorientate
Blind
Tremors
Recumbency
Opisthotonus
Convulsions
277
Q

Treatment for cerebro-cortical necrosis (CCN) in lambs?

A 
Vitamin B1 IV (slowly)
Vitamin B1 IM every 12 hours
For 3 days
House quietly
Vision should return in 5-7d
278
Q

What causes listeriosis of sheep? Age affected? What part of brain does it reach?

A

Listeria monocytogenes
Associated with feeding poorly preserved silage, soil contaminated (mouldy)
18-24mo common - changing molar teeth allowing buccal tissue infection
Ascending infection to brainstem

279
Q

Clinical signs of Listeriosis in sheep?

A

Encephalitis, septicaemia
Anorexia
Depression
Unilateral hemiparesis
Trigeminal nerve paralysis - salivation, food impacted in cheek
Facial nerve paralysis - drooped ear, lowered eyelid, deviated muzzle, loss of blink
Abortion (1-2 weeks after feeding poorly preserved/soil contaminated/mouldy silage)

280
Q

Diagnosis of Listeria in sheep?

A

Clinical signs
CSF tap
PM

281
Q

Treatment for Listeria in sheep?

A

Good if caught early
Gold standard for 75kg ewe:
- 6g benzylpenicillin IV
- 20ml procaine penicillin IM (divided sites, one dose on day of scam)
-1ml/kg dexamethasone IV
- 5ml procaine penicillin daily for 5 days
Supportive care
Remove silage
Septicaemic listeriosis at lambing - hopeless prognosis

282
Q

What causes ‘Gid’ in sheep?

A

Taenia multiceps
Eggs ingested by sheep
Develop in brain cerebrum and cerebellum (coenuris cerebralis)
Dog primary host

283
Q

Clinical signs of Gid in sheep?

A 
Gradual onset
Circling
Contralateral blindness
Head tilt
Skull softening
284
Q

Treatment of Gid in sheep?

A

Surgically remove cysts
Good prognosis if cerebral location
Poor prognosis if cerebellar location

285
Q

Which agents can cause otitis media causing vestibular disease?

A

Pasteurella spp
Streptococcus
T pyogenes

286
Q

Common neurological problems of adult sheep?

A 
Cervical sub-luxation (paresis, rams fighting)
Gid cyst
Listeriosis
Brain abscess
Louping ill
Trauma accident
Pregnancy toxaemia
Hypocalcaemia
Hypomagnesaemia
Wobbler - texels
Scrapie
287
Q

What is classical scrapie?

A

Infectious neurological disease of sheep
Fatal, chronic, progressive brain disease of sheep
TSE, prion disease

288
Q

How is atypical scrapie different to classical?

A

Very rare

Non infectious, sporadic

289
Q

What is involved in the statutory scrapie control?

A

TSE testing scheme - annually, fallen and slaughtered stock and from infected flocks/herds
TSE feed controls - e.g. illegal to feed animal protein to ruminants, and feeding of processed animal protein to all farmed animals
SRM controls at abattoirs - specified risk material removed from sheep >6mo and incinerated (brain, spinal cord, spleen)

290
Q

Private scrapie controls?

A

SRUC
Scrapie monitoring scheme - annual flock inspection, samples and test fallen stock
Scrapie genotyping scheme - breeding stock, checks for susceptibility to disease

291
Q

Causes of thin ewes?

A

Teeth/oral lesions
Poor nutrition - hill ewes over winter, late pregnant ewes, inadequate grazing, poor forage quality
Chronic disease - respiratory, alimentary

292
Q

Economic impacts of thin ewes?

A

Pre-tupping - reduced ovulation so less lambs
Low lamb birth weights
Pregnancy toxaemia and poor colostrum quality
Low milk production so poor lamb growth
Ewe deaths

293
Q

How to age sheep using incisors?

A 
8 incisors
Lamb - all small
1 year - centre pair tall
2 years - 2 centre pairs tall
3 years - 3 centre pairs tall
4 years - all tall
294
Q

Causes of adult sheep molar problems?

A 
Ageing
Periodontal disease
- bacteria
- malocclusion
- diet - uneven wear, feeding of root crops, mineral imbalances
295
Q

Causes of infections/abscesses/discharge of the mouth of adult sheep?

A

Necrotic stomatitis - F necrophorum
Wooden tongue - Actinobacillus lignerisei
Lumpy jaw - Actinomycosis bovis
Caseous lymphadenitis

296
Q

History, clinical signs and prognosis of pharyngeal trauma with dosing guns in adult sheep?

A

Common!
History: few days/weeks after drenching, number of sheep affected
Dull, depressed, inappetent, weight loss
Halitosis, pain, cellulitis
Poor prognosis - euthanasia, penicillin prolonged courses

297
Q

Common respiratory diseases of adult sheep?

A 
Laryngeal chondritis
Jaagsiekte (OPA)
Maedi visna
Chronic suppurative pneumonia
Mannheimia haemolytica
298
Q

What is laryngeal chondritis of adult sheep? Breeds/sex prone? Clinical sign?

A

Abscessation of arytenoid cartilages
Common in Beltex and texels
Rams more common
Loud inspiratory dyspnoea

299
Q

Treatment for laryngeal chondritis of adult sheep?

A

Early
Corticosteroids and broad spectrum LA antibiotics
Temporary tracheostomy tube
May not recover/may reoccur

300
Q

What causes Jaagsiekte/Ovine Pulmonary Adenocarcinoma (OPA)? What does it cause? Which gene is important? What does it target?

A

Jaagsiekte Sheep Retrovirus (JSRV)
Progressive and fatal pulmonary carcinoma
Oncogenic (env gene is the oncogene)
Overproduction of type II pneumocytes -> overproduction of surfactant
Chronic wasting disease

301
Q

Spread of OPA? Incubation period? Clinical signs?

A 
Spread via lung fluids and aerosols
Long incubation of 2-4y
Sudden death
Weight loss
Increased respiratory effort
Exercise intolerance
Panting
302
Q

Diagnosis of OPA? Treatment?

A 
Clinical signs
Crackles and wheezing lung sounds
Ultrasound - lung consolidation
Wheelbarrow test - do quick and stop as soon as fluid appears as distressing for sheep, PTS if +ve
PM for definitive
No treatment - PTS
303
Q

Control of OPA?

A

Biosecurity - buy from known history farms, double fencing, closed flocks
Cull thin sheep/resp signs
Don’t keep offspring for breeding
Reduce close contact housing
Consider outdoor lambing
Vaccine has poor immune response
No reliable test to enable test and cull/testing of bought in

304
Q

What type of virus causes Maedi visna? What forms of the disease are there? Pathology?

A

Small Ruminant Lentivirus (retrovirus) - slow progressive disease
Maedi = chronic respiratory disease, can also cause chronic mastitis and arthritis
Visna = neurological signs
Pathology:
- Infects monocytes
- Progressive lymphoid infiltration and smooth muscle hyperplasia in lungs

305
Q

Route of infection of maedi visna? Incubation period?

A

Infected when young from mother’s milk/colostrum, respiratory route
Incubation period is several years
Clinical signs >2y, usually 4-5

306
Q

Clinical signs of the respiratory form of Maedi Visna?

A

Weight loss
Increased respiratory effort
Exercise intolerance

307
Q

Clinical signs of the neurological form of Maedi Visna?

A

Less common
Weight loss
Abnormal gait, ataxia, incoordination, paralysis
Circling, head tremor etc

308
Q

Control for Maedi Visna in sheep?

A

Cull
Don’t breed from their offspring
Stocking rates, housing
Difficult as by the time clinical signs seen, 50% may be infected
Test and cull/create separate flocks
Virus latent in genome and avoids immune system so no vaccine
Buy from MV accredited stock

309
Q

Do sheep develop immunity to fluke?

A

No

310
Q

What climate do fluke like?

A

Warm, wet

311
Q

Fasciola hepatica life cycle?

A 
Eggs shed by sheep/cow
Develop into miracidia 
Miracidia must swim and find mud snail by 24h after hatching from egg or dies!
Cercariae released from snails
Encyst on grass as metacercariae
Metacercariae eaten by sheep/cow
312
Q

Why does rain increase fluke?

A

Increases snail habitats
Allows development of fluke eggs
Miracidia can find snails
Dispersal of cercariae from snails

313
Q

What temperatures are needed for fluke development outside the host?

A

> 10C for miracidia to develop in egg

>15C for eggs to hatch and multiplication in snails

314
Q

When can fluke cause disease in sheep?

A

Summer infection of snails: disease in sheep in Autumn

Winter infection of snails: disease in sheep in summer

315
Q

When is acute fluke acute disease seen? Which stage of the parasite causes disease? Clinical signs?

A 
2-6 weeks after ingestion of very large numbers of metacercariae
Sept-Dec
Severe haemorrhage due to migration of immature stages through the liver
Sudden death
Weakness
Pale
Dyspnoea/tachypnoea
Tachycardia
316
Q

When is subacute fluke acute disease seen? Which stage of the parasite causes disease? Clinical signs?

A

Metacercariae ingested over longer time than acute
Reach bile ducts, haemorrhage to liver en route
Late Autumn onwards
Haemorrhage anaemia
Hypoalbuminaemia
Weight loss
Enlarged liver
Submandibular and facial oedema
Secondary clostridial infection - black’s disease
Common clinical presentation in UK

317
Q

When is chronic fluke acute disease seen? Which stage of the parasite causes disease? Clinical signs?

A 
Late winter/early spring 4-5 months post ingestion
Jan-March
Hepatic fibrosis and cholangitis
Hypoalbuminaemia
Anaemia
Weight loss
Submandibular oedema
318
Q

Diagnosis of fluke in sheep?

A

History and clinical signs
FEC - low but often presence
Haematology - hypo chromic microcytic anaemia, eosinophilia
Biochemistry - AST, GLDH, GGT 13d post infection, hypoalbuminaemia, hyperglobulinaemia
ELISA
PM
Abattoir returns

319
Q

When will fluke egg counts, serum ELISA antibody and coproantigen be present to diagnose fluke?

A

Fluke egg count - 12 weeks post infection, fluctuates
Serum ELISA antibody - from 3 weeks post infection but only indicates exposure not whether active infection (good for monitoring naive animals e.g. lambs)
Coproantigen - 8-10 weeks (2-3 weeks before fluke eggs seen), drops quickly after treatment so is used as a drench test

320
Q

Treatment for fluke?

A 
Triclabendazole - kills all stages but resistance probem
Treat and move to low risk pasture
Closantel
Nitroxynil
Oxyclozanide
Albendazole
321
Q

Control of fluke?

A
  1. Avoid (reduce stocking density in autumn, assess farm known risk areas e.g. drain wet fields, biosecurity, closantel for bought in animals)
  2. Monitor (serum ELISA, coproantigen, FEC, forecasting to predict high risk years, PM sudden deaths)
  3. Targeted drug treatments
322
Q

When to dose for fluke?

A

Autumn against immature stages (TCBZ)
Winter immature and adults (Close/Nitrox)
Late spring remove all adults (albendazole)
High risk year/farm:
- extra dose in November for immature (TCBZ)
- extra dose in June for winter infection of snails (TCBZ)

323
Q

How to prevent flukicide resistance?

A

Rotational use of drugs - use 3 causes throughout year
Only use triclabendazole when necessary (autumn)
Spring dose against adults important to prevent egg output and summer infection of snails
Quarantine drenching - closantel/nitoxynil
Test for resistance to TCBZ - composite faecal egg count reduction test

324
Q

What causes Johne’s disease? Clinical signs in sheep? Strains?

A 
Mycobacterium avian paratuberculosis
Non specific clinical signs
Weight loss
Anaemia
Bottle jaw
High parasite burdens
Cattle and sheep strains - may transmit between
325
Q

Characteristics of Mycobacterium avium paratuberculosis?

A

Can survive for many months on pasture
Shed in faeces (milk)
Oral route (in utero and colostrum but less important)

326
Q

At what age is Johne’s typically seen in sheep?

A

3-4yo

327
Q

Where does MAP replicate? How does it cause disease?

A

In GI lymph nodes and gut
Cellular infiltration, thickening of intestines
Malabsorption and protein losing enteropathy
Hypoalbuminaemia

328
Q

Diagnosis of Johne’s disease in sheep?

A 
Difficult in live animals
-faecal smear for acid fast organisms
-serology - low se, good sp
-low serum albumin
-faecal culture
SRUC sheep: MAP culture+PCR
PM - histopath ileocaecal junction and enlarged distal mesenteric lymph nodes
329
Q

Control of Johne’s disease?

A 
No treatment
Don't graze sheep and goats with cattle
Low stocking rates
Use plenty of bedding and dag ewes if necessary
Cull suspected/confirmed cases asap
DOn't keep offspring of infected animals
Provide mains water from clean troughs
Wean lambs onto grass not grazed by adult sheep this year
330
Q

By how much does the Johne’s vaccine reduce shedding and numbers of clinical cases?

A

50%

331
Q

What is pink eye in sheep? Cause? Risk factors?

A

Ovien Infectious Keratoconjunctivitis
Mycoplasma conjunctivae
Mixing of sheep, tupping time or feeding

332
Q

Treatment for pink eye (OIKC) of sheep?

A 
Early cases respond better
Isolate affected sheep
Look at risk factors for close contact
LA oxytet IM of those affected
Plus topical antibiotics
333
Q

What causes anterior uveitis/silage eye in sheep?

A

Listeria monocytogenes

Associated with feeding baled silage in ring feeders

334
Q

Clinical signs and treatment for anterior uveitis/silage eye in sheep?

A 
Blephorospasm
Cloudiness of cornea
Swollen, folded iris
Material in front of eye chamber
Sub-conjunctival oxytet and dexamethasone
Systemic penicillin
Remove source
335
Q

At what level is abortion in a sheep flock a problem?

A

> 2%

336
Q

Main 4 causes of abortion in sheep? Others?

A

Chlamydophila abortus (Enzootic abortion)
Toxoplasma
Campylobacter foetus foetus (C jejuni)
Salmonella abortus ovis

Others:

  • Border disease virus
  • Listeria monocytogenes
  • E.coli
  • Tickbourne fever
  • Coxiella burnetti (Q fever
  • Yersinia spp
  • Fungi
  • Trueperella pyogenes
  • Bluetongue
337
Q

Enzootic abortion in sheep: Aetiology? Features of agent? Zoonotic? Sources and routes of infection?

A

Chlamydia abortus:
- gram negative cocci
- intracellular reproductive stage
- extracellular infectious phase
Zoonotic to pregnant women and immonocomprised people
Sources of infection:
- aborting ewes are main sources: discharged products of abortion heavily contaminated and viable for several days
- carrier ewes less commonly: may or may not abort, shed at lambing +/- at oestrus
Route of infection:
- oral
- close contact at lambing facilitates spread

338
Q

Outcomes of exposure to Chlamydia abortus in sheep?

A
  1. Exposure of pregnant ewe:
    - if >90d pregnant, may abort
    - if <90d pregnant, may abort after 90d or may become latently infected by harbouring agent in reproduction tract and abort at next pregnancy
  2. Exposure of non pregnant ewe:
    - becomes latently infected harbouring infection in reproduction tract and aborts at following lambing season
  3. Ewe lamb born to infected ewes:
    - can become infected and abort at their first lambing
  4. Exposure of a ewe who already aborted from infection:
    - most ewes become immune and will not abort again
    - some will become carriers and shed at oestrus and lambing
339
Q

What is the abortion pattern seen with Chlamydia abortus when newly introduced to a flock by latently infected replacement ewes?

A

Relatively low levels of abortion in first year
Abortion storms of 30% in the following year
Then endemically infected flocks have abortion rate of 5-10%

340
Q

Pathology caused by Chlamydia abortus in sheep?

A

After 90d bacteria replicate in trophoblastic epithelial cells
Severe placentitis is with thickening and necrosis
Placentitis: inflammation of placenta affects transport nutrients and hormone production -> death or damage to lamb
Inflammation of lamb’s internal organs

341
Q

Clinical signs of Chlamydia abortus in sheep?

A

Abortion after 90d of pregnancy, often in last month
Death of lambs or birth of weak lambs or birth of one live and one dead
Ewes vaginal discharge couple days
Rarely sheep are ill, occasionally metritis (can be fatal)

342
Q

Diagnosis of Chlamydia abortus in sheep?

A

Diagnosis:

  • abortion of well preserved lambs in late pregnancy
  • submit aborted lamb’s placenta to lab
  • gross Pathology: necrotic placentitis
  • modified Ziehl Nielson stain: placenta, vaginal discharges or fetus to identify organsim
  • culture techniques
  • PCR available
  • if no abortive material can test vaginal discharges, serology on ewes (care with interpretation, paired serology is best)
343
Q

Control of enzootic abortion (chlamydia abortus) in sheep?

A 
During an outbreak
1) Stop spread of infection:
- burn abortion material and bedding
- clean and disinfect pens
- isolate aborted ewes
2) Reduce further abortions:
- treat remainder of flock with killed
inactivated vaccine
- or treat all ewes yet to lamb (>90 days) with 20mg/kg oxytetracycline long acting and repeat in 2 weeks
The year following an outbreak:
- vaccinate all ewes pretupping
- if consider there is risk of ewes being infected from previous year, it is acceptable to repeat oxytetracycline injections the year following an outbreak (not acceptable after that)

Also:
- clean flock: don’t buy in, buy EAE accredited sheep SRUC health scheme, breed own replacements

344
Q

Toxoplasma gondii in sheep: Definitive host? Life cycle?

A

Definitive host = cats
Reservoir for cats is wildlife
Cats shed millions of oocysts in faeces and then become immune
Oocysts contaminate sheep feed and water - very resistant (>500d)
Sheep ingest oocysts from pasture, bedding, feed or water etc contaminated by cat faeces

345
Q

What are the possible outcomes of a sheep toxoplasma infection?

A
  1. Non pregnant when exposed: develop immunity
  2. Early pregnancy:
    - foetal resorption (ewes will present as barren)
    = important cause of low scanning %
  3. Mid pregnancy:
    - foetal death
    - foetal retardation
    - mummification
  4. Late pregnancy:
    - abortion of freshly dead lambs
    - weak lambs with high mortality rate
    - live and immune lambs
    - (depends on lamb and placenta’s ability to deal with infection)

Aborted ewes become immune
In endemically infected flocks often see mainly abortion in younger ewes

346
Q

Diagnosis of Toxoplasma in sheep?

A

Submit foetus placenta, or paired blood sample ewe for serology
Gross pathology of Placenta: frosted strawberries cotyledons
Histopathology of foetus and placenta
Immunofluorescent
Antibody test of Toxoplasma antigen in placenta
PCR
Serology

347
Q

Control of Toxoplasma in sheep?

A 
Biosecurity:
- Control cat population
- Control rodents
- Secure feed stores to prevent access
Vaccination:
- Toxovax = live attenuated strain, undergoes limited multiplication in host
- Given at least 3 weeks prior to tupping
- Not in pregnant animals
- Booster as data sheets
348
Q

Zoonotic potential of Toxoplasma?

A

Particularly immunosuppressed people and pregnant women

From undercooked meat, raw sheep milk, cat faeces, lambing

349
Q

Salmonella abortus ovis in sheep: Sources of infection? What is seen? Diagnosis?

A

Sources of infection:
- Apparently, healthy carrier sheep (e.g. bought in sheep)
- birds, rodents, wildlife contaminating feed etc
Outbreaks of abortion in last 1/3 pregnancy (can be abortion storms)
Ewes often systemically ill: metritis following abortion
Diagnosis based on isolation of organism from aborted material:
- foetus and placenta
- foetal stomach

350
Q

Treatment/control of Salmonella abortus ovis in sheep?

A 
Reduce spread:
- Isolate aborting ewes
- Burn infected material
- Clean and disinfect pens
Consider antibiotic treatment:
- Sick sheep
- Whole flock
- Long Acting oxytetracycline, repeat
7-10day
- NSAIDs
Consider source of infection:
- Sheep, biosecurity measures (closed flock, don't mix bought in sheep until after lambing)
- Other animals e.g. wildlife reduce exposure
- Access to feeds, lambing sheds
351
Q

Campylobacter fetus fetus in sheep: What happens? Sources of infection?

A 
Abortion in last 6 weeks or weak born lambs, 1-4 weeks post infection
Ewes may become ill with metritis
Sources of infection:
- carrier sheep
- contaminated feed or water
- aborted material
- birds
Can occur in storms
Very contagious in environment
Diagnosis:
- smear and culture of placenta, fatal stomach and liver
Control:
- isolate aborting ewes and dispose of material
- broad spectrum antibiotics
- no vaccine in UK
- risk often to bought in replacements
- zoonotic!
352
Q

Border disease: What is it caused by? Maintenance of infection? Signs? What does disease depend on?

A 
Pestivirus closely related to bovine BVDV and CSF
Infection introduced and maintained in flock by PI animals
Pregnant <60d: 
- fetal death (barren)
- mummification
- abortion
- still birth
- 50% survive and are normal
Pregnant 60-85d:
- foetal death
- abortion
- still birth
- hairy shakers: encephalitis (cerebral hypoplasia, ataxia, hypermetria), long limbs
- small weak lambs
- PI (can look normal)
Pregnant >85d:
- normal Ab positive lambs
Non pregnant: no clinical signs
What happens with pregnant ewes depends on:
- stage of pregnancy
- immuno-competence of foetus
- strain and dose of virus
353
Q

Diagnosis and control of Border Disease in sheep?

A

Diagnosis:
- clinical signs of hairy shakers
- PM lambs (histology, virus isolation)
- Ab serology from ewes
- Ag PCR from ewes
- test suspect PIs from 3mo for Ag
Control:
- if bought in and diagnosed, don’t breed from entire lamb crop and try to identify PI from the bought in sheep and slaughter her
- if endemic, test whole flock for PI and cull?
- biosecurity: closed flock, test bought in for PIs (virus PCR on serum)

354
Q

Coxiella burnetti (Q fever): Which animals infected? Spread? Transmission? What does it cause? Diagnosis? Control?

A

Zoonotic (fever, vom diarrhoea, headache)
Infects many species including arthropods, sheep and goats
Spread in infected placenta/foetus/fluids/milk and urine and faeces, dust
Very resistant in environment
Infection via direct contact and inhalation
Abortion storms, still births, poor lambs
Diagnosis:
- Serology, bacteriology and histopathology of foetus
Control:
- Isolation of infected animals
- Burn contaminated material
- Oxytetracycline injectable
- Pasteurisation of milk

355
Q

Schmallenberg: Which family of viruses? Transmission? Signs in sheep and cattle? When must infection occur for foetus to be affected? Control?

A 
Bunyaviridae family
Transmitted by Culicoides 
Signs in cattle:
- mild disease
- diarrhoea, fever, milk drop of 50%
- recover quickly in 2-5d
Sheep:
- no apparent clinical signs
- increased return to service
- increased barren ewe rate
Congenital malformations: 
- may be born alive or dead
- may be >25% abnormal births
- bent limbs and fixed joints
- twisted neck or spine
- domed head
- short lower jaw
- live 'dummy'
- blindness
- wobbly
- inability to suck
- fitting
Small window of infection of foetus in sheep: 26-56 days
Control:
- vaccine but not always available
- delay breeding to midge season finished?
356
Q

What to do if suspect Schmallenberg?

A

Not notifiable

They will send off samples which are tested for free to check for the virus

357
Q

What to do if an abortion case in sheep?

A 
Isolate ewe
Remove contaminated material and burn
Clean and disinfect pens
Beware zoonotic risk
Take appropriate samples:
- foetus and placenta
- foetal stomach, foetal fluids, placenta
- if foetus and placenta not available, blood sample and vaginal swab from ewe
358
Q

Which bacteria are involved inPasteurellosis of sheep?

A

Mannheimia haemolytica

Bibersteinia trehalosi

359
Q

Transmission of scrapie?

A

Vertical:
- = mother to offspring in utero
Pseudo-vertical:
- parten to offspring at birth, from infected birth tissues
Horizontal:
- adult to adult/lamb from infected sheep
Contaminated land:
- where infected sheep used to live (decades before)
Iatrogenic:
- needle contamination

360
Q

What are the 5 important PrP alleles in UK sheep for scrapie? Resistance?

A 
ARR - resistance
AHQ - resistance with VRQ
ARG - susceptibility
ARH - susceptibility with VRQ
VRQ - susceptibility
361
Q

Where to polymorphisms of PRP occur and which are linked to scrapie?

A

Polymorphisms known at 17 codons

Disease linkage to scrapie at codons 136, 154 and 171

362
Q

What are the components of the national scrapie plan? What about goats?

A

Scrapie-free farms:
- Voluntary scheme, aimed to protect currently uninfected farms by increasing level of genetic resistance
- lambs and sheep genotyped at no cost, under condition that those bearing VRQ allele will be culled
Scrapie-infected farms:
- Compulsory scheme known as the Compulsory Scrapie Flocks Scheme (CSFS)
- Compulsory slaughter of entire flock (with later restocking) OR compulsory genotyping of entire flock, followed by culling of all animals encoding VRQ (except ARR/VRQ)

Goats also get scrapie (and BSE): TSE control is by whole herd killing, as there is not significant genetic resistance

363
Q

What is atypical scrapie?

A

Characterised by:

  • unusual distribution of PrPSc in brain
  • High age: mean 6.5 years
  • mostly single cases in flocks

4th year (44 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions