Sheep Flashcards
Describe the ‘ram effect’
Introduction of ram triggers brain to produce LH (2 forms: pulsing-> follicle growth; and surge-> ovulation). Basically it triggers cycling (as long as environmental conditions eg light are also correct)
Why should you encourage farmers to do PMs on sheep that died suddenly?
Could have died from something that is a risk to other animals
What should you ask when taking a history of a sheep that died suddenly?
Clinical signs of other sheep Age Season (ie parasites) Proximity to lambing (ie metabolic disease) Indoors or grazing Changes in management? (Eg diet, transport) Weather changes Recent treatments Vaccination history Anthelmintic treatments Recent gathering or handling?
Why should you look at a sheep/ flock before doing a clinical exam?
To look for neurological signs eg ataxia, head tilt
Give some causes of sudden death in neonatal lambs
Birth trauma eg rib fractures, dystocia Starvation Hypothermia Clostridial disease (dysentry, tetanus) Neonatal infections (meningitis, septicaemia, watery mouth) Intestinal torsion Predators
At what age should you blood sample lambs to test colostrum transfer?
2-7 days old
Give some causes of sudden death in growing lambs
Infections (clostridial disease, pasteurellosis) Urolithiasis Parasitic gastroenteritis Fluke Rumen acidosis Plant poisoning
Give some causes of sudden death in adult sheep
Metabolic disease (eg hypocalcaemia) Parasitic disease (eg fluke) Plant poisoning Infection Clostridial disease
Give some common causes of plant poisoning in sheep
Yew
Acorn
Laurel
Rhododendron
Give some clinical signs of plant poisoning in sheep
Abdominal pain (strong indicator)
Neurological signs
Sudden death
How do you treat plant poisoning in sheep?
Supportive treatment
Rumenotomy to remove poison material
What is the causative agent of pneumonic pasteurellosis?
Mannheimia haemolytica (normal inhabitant of nasopharynx)
What are the 2 types of pasteurellosis in sheep?
Pneumonic and systemic
Give the clinical signs of pneumonic pasteurellosis in young and old lambs
Young lambs: severe septicaemia
Older lambs: pneumonia
What enhances pneumonic pasteurellosis in sheep?
Disease is associate with other factors eg stress, poor colostrum status
How do you treat pneumonic pasteurellosis?
Long active Oxytetracycline or amoxicillin
How do you control pneumonic pasteurellosis?
Vaccination from 3 weeks old, booster ewes before lambing to protect lambs aswell
(Heptavac P)
What is the causative agent of systemic pasteurellosis?
Biebersteinia trehalosi (normal inhabitant of URT)
What clinical sign is seen with systemic pasteurellosis?
Sudden death in 6-10 month old lambs
What is the treatment for systemic pasteurellosis?
Long acting Oxytetracycline
Vaccination
Why is diagnosis of clostridial diseases in sheep done at post mortem?
Mostly causes sudden death
Give some trigger factors of clostridial diseases in sheep
Changes in management
Injury/trauma/insult
Endoparasites
Poor hygiene
Which clostridium causes lamb dysentry?
Cl. perfringens B
Which clostridium causes pulpy kidney in sheep?
What age of sheep are affected?
What are the clinical signs?
Cl. perfringens D
Lambs aged 4-10 weeks old, or finishing lambs 6 months +
Sudden death, may see ataxia and/or opisthotonus
Which clostridium causes abomastitis in sheep?
What age of sheep are affected?
What are the clinical signs?
Cl. sordelli (‘sore belly’)
4-10 weeks old, creep fed (high levels of concentrates in feed)
Sudden death or bloat due to displaced, distended abomasum
Which clostridium causes blackleg in sheep?
Cl.chauvoei
Which clostridium causes botulism in sheep?
Cl.botulinum C
Which clostridium causes tetanus in sheep?
Cl.tetani
What causes lamb dysentery?
Cl.perfringens type B
How can you control clostridial disease in sheep?
Vaccinate ewes 4 weeks before lambing (also protects lamb), annual booster
Start lambs own vaccination course from 3 weeks old
Vaccine: Covexin 8 and 10 or Bravovoxin 10 or Heptavac P
Give some notifiable diseases of sheep
Anthrax
Bluetongue
Foot and Mouth
Scrapie
What causes Anthrax?
Bacillus anthracis
If a sheep had foot and mouth disease, where would you see blisters?
Tongue, teats, coronary band, dental pad
How is Bluetongue spread?
Culicoides imicola
Give some clinical signs of Bluetongue
Fever Swelling of head and neck Lameness Mouth ulcers Drooling Skin haemorrhages Respiratory problems Tongue swelling (rare)
What are the 2 forms of scrapie?
Classical and atypical (rare)
Describe classical scrapie in sheep
Infectious neurological disease of sheep
Fatal, chronic, progressive TSE
Prion disease: prions accumulate in brain -> neuro dysfunction: excitable, nervous, depressed, aggressive, trembling, ataxia, high step ataxia, wide back legs, pruritus, wool loss due to scratching
2-5 years old
If you suspect scrapie who should you report it to?
AHVLA
How do you treat sheep scab?
Macrocyclic lactones or organophosphate dip
Give some problems caused by nutrition seen around lambing time
Metabolic disease: -Pregnancy toxaemia or twin lamb disease -Hypocalcaemia -Hypomagnesaemia Ewe: -Mastitis -Dystocia (over feeding) Lamb Mortality/Morbidity: -Low lamb birth weight -Poor colostrum -Poor milk production
Briefly describe pregnancy toxaemia in sheep
Lack of glucose availability due to consumption by foetus. Hypoglycaemia -> neurological signs
Hyperketonaemia
Why are molasses given to ewes carrying triplets?
They are very high in energy
What is ‘milk fever’?
When does it occur in sheep and cows?
Hypocalcaemia
Sheep: before lambing
Cows: after calving
Where should you not inject magnesium into sheep?
Veins -> death
What is meant by ‘flushing the ewe’?
Feeding the ewe so she is gaining weight about 2 weeks before tupping
Increasing the BCS by 0.5 will improve the number of eggs produced#
White muscle disease in lambs and calves is caused by a deficiency in what?
Selenium
How should a ewe’s BCS change during mid-pregnancy?
Maintain BCS or decrease by 0.5 as this is when the placenta develops. Care: if underfed -> small placenta -> low birth weights
What are the aims of feeding a ewe in late pregnancy?
To support foetal growth
To support mammary tissue development and colostrum production
To maintain ewe health and prevent pregnancy toxemia (ketosis)
To ensure lambs are born strong, healthy and of proper birth weight
When should we start feeding ewes cake during pregnancy?
90 days to lambing
What major events happen in a ewe when there is 90 days to lambing?
Uterus is expanding -> rumen capacity decreases
70% of foetal growth occurs
Colostrum development begins
What should you measure in a ewe’s blood 3 weeks before lambing?
BOHB (ketone bodies), albumin, urea
Give some problems with fat ewes
More prone to pregnancy toxemia Fat ewes experience more dystocia More likely to prolapse Large fetuses can cause dystocia Oversized lambs have a higher mortality Fat is expensive to put on
When are lambs weaned?
12-16 weeks old
Give some clinical signs of pregnancy toxaemia in sheep
Separate from group Inappetant Apparent blindness Tremors of face and ears Can progress to recumbency Dead foetuses Death BOHB >3mmol/L
What is a ‘hybrid’ feeding system for lactating cows and what are some problems with it?
TMR at barrier and extra cake in parlour
Risk of acidosis
Cow eats less at barrier (-> less long fibre)
Shouldn’t be feeding in parlour (bad for rumen health- peaks of acidosis)
What is the ‘Dolly Parton effect’?
Get peaks of acidity after milking seen when giving cake in the parlour: cake causes a drop in pH (temporary acidosis), then pH returms to normal
What do we want rumen pH to be?
Around 6.5
How can we monitor a cow’s nutritional status?
BCS and observation (DMI, cudding, rumen fill, lying time)
Milk quality
Can sieve faeces to look for fibre
Biochemistry (metabolic profiles)
What condition score should a dry cow be?
What about during peak lactation?
Dry: 2.5 - 3
Peak lactation: 2 - 2.5
What score is used for rumen fill? What score is optimum?
Scored from 1-5. Should be 3-4
What are the 5 scores of faeces?
1= brick solid 2= like a horse 3= target 4= like pudding 5= diarrhoea
What % of cows should be cudding at any one time?
75-80% (if not sleeping or actively eating)
A low butterfat % in milk indicates what?
Lack of fibre in diet
The comfort quotient for cattle should be which value?
85%
Which biochemical tests would you carry out to assess nutritional status?
BHOB (betahydroxybuterates)-ketone body. Indicative of fat mobilisation.
NEFA-evidence of fat mobilisation (high levels=serious health problem)
Urea
How many cows would you test when doing biochemical tests to assess nutritional status?
At least 12 per group
What should you look at in a diet when assessing cow nutritional status?
Fodders in clamps (DM, smell, texture)
Diet as fed (smell, consistency, evidence of sorting, feed surface, feed barrier, should always be food in front of cows)
How can you predict DM of a fodder?
25%= can easily squeeze water out 30%= cannot squeeze water out
What maintenance should a cow get per day?
65-70 MJ/day
How much energy is required for a cow to produce 1L milk?
5MJ/litre
What allowance should you provide when calculating diets for cows in late pregnancy?
20-40MJ
20MJ for early dry period
40MJ for transition period
What should the fodder:concentrate ratio be for cows?
60:40 fodder:conc is best
If changing a cow’s diet, what time period should you do it over?
3 weeks
What DMI should you aim for when feeding cows?
3-4%
How much energy do the following contain: Good silage Average silage Maize silage Big bale silage Straw Hay Concentrates
Good silage: 11-11.5 MJ/Kg DM Average silage: 10-10.5 MJ Maize silage: 11-11.3 MJ Big bale silage: 8-10 MJ Straw: 6.5 MJ Hay: 9 MJ Concentrates: 12.5 MJ
How does maedi visna affect sheep?
Causes encephalitis (‘visna’) and chronic pneumonitis (‘maedi’)
How do you treat sheep scab?
2 ivermectin injections, 7 days apart)
What is the target % for lamb mortality from birth to sale?
8%
How much colostrum should a newborn lamb receive?
50ml/kg in first 6 hours of birth (200ml)
250ml/kg in first 24 hours (1 litre)
When can you test to see if a lamb has had sufficient colostrum?
Zinc sulphate turbidity blood test <7 days old
When do you wean a lamb?
4-6 weeks old, at 15kg
What is the normal rectal temp of a newborn lamb?
39-40oC
How long does brown fat last (in lambs)?
6 hours
How do you treat a lamb with hypothermia with a rectal temp of 37-39oC which can still suckle and hold its head up?
Dry it if wet Feed warmed colostrum Check ewe's milk/health Return to ewe Provide shelter Supervise
How do you treat a lamb with hypothermia with a rectal temp of <37oC which is weak, depressed, arched back or recumbent?
Intra-peritoneal 20% glucose, 10ml/kg Dry the lamb Warm to 37oC Give colostrum (50ml/kg) Warm to 39oC Return to ewe Provide shelter and monitor
Which sized needle should you use when giving a lamb an intra-peritoneal glucose injection?
19G 1”
What causes watery mouth in lambs?
Lack of colostrum/delay in getting colostrum allows gram -ve bacteria into the SI (esp. E.coli)
Give some clinical signs of watery mouth
Profuse salivation, reluctance to suck, depressed, swollen abdomen (gut stasis), collapse, death (endotoxaemia)
How do you treat watery mouth?
Can be fatal
Oral fluids (50ml/kg q6 hrs)
NSAIDs eg flunixin
Broad-spectrum ABs eg amoxicillin/clavulonic acid
Give some causes of neonatal diarrhoea in lambs
Lamb dysentery (Cl. perfringens type B) E.coli Rotavirus Cryptosporidia parvum Salmonella (typhimurium or dublin)
What is the most common cause of joint ill?
Streptococcus dysgalactiae
Give some clinical signs of joint ill
Lame, heat, pain, swelling over joints
Reduced suckling, ill thrift
Neuro signs if spinal abscesses occur
How do you treat joint ill?
ABs (penicillin, amoxicillin) for at least 5 days
Poor prognosis unless caught early
Give some clinical signs of navel ill
Hunched back, poor body condition, poor suckling
Navel moist, swollen and painful
Swelling may continue to bladder or liver
How do you treat navel ill?
ABs
Poor prognosis
What would you suspect in a lamb that is weak, depressed, fitting, and has congestion of blood vessels around the eyes?
Meningitis
Give some clinical signs of Drunken Lamb Syndrome
Acute ataxia and incoordination -> recumbency
Death quickly follows within 24-48 hrs
How can you treat Drunken Lamb Syndrome?
50mmol sodium bicarbonate dissolved in tap water given orally to treat the metabolic acidosis
Amoxicillin
Give some clinical signs of lamb nephrosis syndrome
What age of lambs are affected?
2-12 weeks old
Lose condition, diarrhoea, increased thirst
How do you diagnose lamb nephrosis syndrome?
Raised urea and creatinine, metabolic acidosis, hyperkalaemia, decreased albumin globulin ratio
Can you treat lamb nephrosis syndrome?
No
Give the clinical signs of a patent urachus
Swollen umbilicus
Dribbling urine
Why does swayback occur in lambs?
Copper deficiency in ewes
What clinical signs would you see in a lamb with swayback?
HL weakness (problems with myelination of spinal cord)
Which age of lambs usually get coccidiosis?
4-8 weeks old
Give some clinical signs of coccidiosis in lambs
Severe haemorrhagic diarrhoea, tenesmus, fever, weight loss, death
Poor growth
Which Eimeria species cause coccidiosis in lambs?
E. crandalis, E. ovinoidalis
How do you diagnose coccidiosis?
Faecal samples, coccidial count
How do you treat coccidiosis?
House sick animals and separate
Oral fluids
Diclazuril or toltrazuril
How do lambs usually pick up Eimeria (coccidiosis)?
Shed by ewes and older lambs
Which worms contribute to PGE?
Nematodirosis
Teladorsagia
Haemonchus contortus
Trichostrongylus
How is cobalt used in the body?
Used to make vitamin B12 in the rumen
RBC development
Amino acid synthesis
Energy metabolism
Give some clinical signs of cobalt deficiency
Weight loss Anaemia Slow growth Debility Watery eye discharge
How do you diagnose cobalt deficiency?
Vitamin B12 levels in the blood and liver
Response to cobalt therapy
How do you treat cobalt deficiency?
Cobalt drenches/boluses/supplement
Vitamin B12 injections
Give some clinical signs of selenium deficiency
White Muscle Disease:
Ill-thrift in lambs
Weakness, collapse, lameness
Poor reproductive performance in ewes
Give some clinical signs of iodine deficiency
Death, weakness, illness in newborn lambs
Late abortions
Thyroid goitre in lambs
Give some clinical signs of copper poisoning
Intravascular haemolysis and jaundice, ataxia, head-pressing, HBuria, recumbency, death
How do you treat copper poisoning?
Sodium calcium EDTA
Supportive therapy
What causes pneumonic pasteurellosis?
Mannheimia haemolytica (present in the nasopharynx of healthy sheep)
Give some clinical signs of pneumonic pasteurellosis
Pyrexia, mucopurulent nasal discharge, cough, death
How do you treat pneumonic pasteurellosis
Oxytetracycline, amoxicillin for 5-7 days
Give some clinical signs of Mycoplasma pneumonia
Which kind of sheep is it commonly seen in?
Cough, slight nasal discharge
Housed sheep
When is lungworm seen?
Give some clinical signs
Dictyocaulus filaria (thin worm)
July-September in lambs at pasture
Coughing, dyspnoea
What is the target BCS for weaning in lowland sheep?
2.0-2.5
What is the target BCS for tupping in lowland sheep?
3.5
What is the target BCS for lambing in lowland sheep?
3.0
How do you treat pregnancy toxaemia in sheep?
Propylene glycol 50ml twice daily (max 2-3 days)
IV glucose: 50-100ml 40% dextrose; can repeat in a couple of hours)
Give some clinical signs of hypocalcaemia in sheep
Initial weakness and excitement -> recumbency
Dilated pupils, constipated, bloated, comatose, death
How do you treat hypocalcaemia in sheep?
Slow i.v 40-80ml 20% calcium borogluconate or 20-40ml 40% given very slowly, or SC 1ml/kg 20% calcium borogluconate (50-100ml)
When does hypomagnesaemia occur in sheep?
Post lambing, peak lactation
Lush grass or bare pastures
Give the clinical signs of hypomagnesaemia (staggers) in sheep
Rapid onset, neurological symptoms
Excitable, tremors, convulsions death
Found dead
How do you diagnose hypomagnesaemia (staggers) in sheep?
Blood sample: Mg <0.6mmol/L
How do you treat hypomagnesaemia (staggers) in sheep?
20ml-40ml 20% calcium i.v
50ml-80ml 25% Mg So4 s.c
Give some differential diagnoses for sick/recumbent ewes at lambing time
Hypocalcaemia Pregnancy toxaemia Hypomagnesaemia Listeria Mastitis Metritis
