Small ruminants Flashcards
1
Q
Outline the steps involved in undertaking a flock or herd investigation
A
- History: event timeline, determine losses, treatments
- Examination of env: pasture (soil type, availability, water supply), indoors (hygiene, ventilation, overcrowding)
- Examination of animals: at a distance, clinical exam, PM exam
- Use of ancillary aids: parasite tests, haematology, biochem, histopath, etc
- Data analysis and decision making: tentative diag, prognosis, therapy
- Reporting and further monitoring
2
Q
MCQ: the average normal resting heart rate for an adult ewe is:
a. 20-30 beats/min
b. 30-40 beats/min
c. 40-60 beats/min
d. 70-90 beats/min
e. 100-120 beats/min
A
d. 70-90 beats/min
3
Q
What % of ewes should be scanned in lamb after a 5 week, seasonal joining if ewes are in CS 3 or better?
A
95%
4
Q
What type of clovers can cause permanent infertility?
A
Sub clover and red clover
5
Q
When are the three main times that repro loss may occur and when are they diagnosed?
A
- Failure to get in lamb/early embryonic loss –> diag at scanning
- Second half preg +/- frank abortion –> diag before lambing, often at marking
- Neonatal losses 1-5 days –> diag at marking
6
Q
For each BCS >1.5 to 4 you can expect…
A
- 5% increase in conception rate
- increase in lamb birthweight and survivability
- increase in lamb weaning weight
7
Q
How can you increase BCS for reproductive gains?
A
- Change lambing time –> pasture availability
- Some level of supp with grain
- Flushing: provide nutritional spike in lead up to joining
8
Q
Aside from decreased lambing %, what other signs of clover disease may you see?
A
- Dystocia secondary to uterine inertia and fibrotic labia
- Increased rates of pre-lambing vaginal prolapse
- Teat elongation and inappropriate lactation
- Urolithiasis in wethers
9
Q
What is the rate of embryonic mortality in the first 18 days?
A
20-30%
10
Q
What are the signs of abortion
A
- Ewes scanned in lamb detected as likely not in lamb at pre-lambing treatments, skinny, no udder dev
- Frank abortion
- If not scanned at marking: not lactating, lactating but no lamb (udder involuting)
11
Q
What are the three most common causes of abortion?
A
Campylobacter, Listeriosis, Toxoplasmosis
12
Q
Answer the following about Campy:
a. What species cause abortions?
b. What % lamb loss do they cause?
c. How is it transmitted?
d. How can it be prevented?
A
a. C. fetus fetus, C. jejuni
b. 10-60%
c. Ingestion, direct contact with discharges from vagina, aborted foetuses, placenta, crows and magpies can carry
d. Infect ewe hoggets while not pregnant, vaccine (2 doses 3-8 wks apart, yearly booster pre-joining)
13
Q
What are some of the clinical signs of Campy?
A
- Abortion mid to late preg
- Stillbirths
- Births of premature apparently normal but not viable lambs
- Ewes no signs of sickness
- Retention of foetal membranes and dev metritis (rare)
14
Q
How are sheep infected with Toxoplasma?
A
Ingestion of feed or water contaminated with cat faeces (very resistant in env)
15
Q
Describe the clinical signs of Toxoplasma at different stages of pregnancy, including how you would distinguish from Campy
A
- If not preg: no signs
- If early preg: no signs, foetal death and resorption
- If mid preg (d60-120): stillbirth, weak lambs, mummification (distinguish from CAMPY), abortion
- If late preg (>d120): normal offspring (immune)
16
Q
What are the two species that cause Listeriosis and what specific symptoms do they cause?
A
Listeria monocytogenes: abortion, lamb septicaemia, meningoencephalitis
Listeria ivanovii: abortion and enteritis
17
Q
What is the source of Listeriosis infection?
A
Survive for a long time in soil and on decaying vegetation (disease in wet, muddy conditions)
18
Q
What are the two species of Salmonella that cause abortions?
A
S. typhimurium and S. bovis-morbificans (systemic)
19
Q
What causes hairy shaker disease?
A
Ovine pestivirus
20
Q
What are the clinical signs of ovine pestivirus at different stages of preg?
A
Not preg: mild fever, immunity
<50d: foetal death, resorption, abortion, ewes show no signs
50-85d: foetal death and abortion, “hairy shakers”
21
Q
Describe some of the risk factors of preg toxaemia
A
- Very fat ewes (BCS<4)
- Very skinny ewes
- Twins
- Older ewes
- British breeds + crossbreds
- Anything that decreases feed intake e.g foot abscesses, cold weather, transport
- Anything that increases energy req: twins, cold, shearing, GI parasites
22
Q
Describe the clinical signs of preg tox
A
- Dullness
- Loss of appetite
- Lag behind mob
- Recumbency
- Stargaze
- In coma and die
23
Q
Describe the clinical signs of hypocalcaemia
A
- Sudden onset
- Affected ewes become isolated and stiff gait with muscle tremors
- Soon ewes become weak and recumbent
- Fatal if not treated
24
Q
Describe the treatment and prevention of hypocalcaemia
A
- Calcium borogluconate
- Magnesium sulphate
25
Describe the differences between preg tox and hypocalcaemia
1. Preg tox is usually a low number over a longer period after precipitating event vs hypocal can be very large no all at once
2. Demeanor: preg tox = very depressed vs hypocal = BAR but unable to get up, frogs legs sitting position
3. Response to Tx: poor for preg tox, good for hypocal
26
What kind of pastures are high risk for hypomagnesemia?
- Lush grass dominant pastures or rapidly growing fodder crops in late winter are low in Mg
- Fertilisers rich in potassium and nitrogen
- Acid soils may decrease Mg availability
27
Describe some of the clinical signs of hypomagnesemia
- Often found dead in paddock 1-4 wks post lambing
- Ataxia, muscle tremors, tetanic signs
- Collapse, convulsions with severe limb paddling, froth at mouth
- Death w/in 4-6 hrs
28
Describe the treatment and prevention of hypomagnesemia
- Treat ASAP
- Mg + Ca IV/SC therapy followed by SC Mg salts
- Prevent by min. stress and handling in first wks of lactation
- Hay with Mg oxide (causmag)
29
Question: describe a simple post-mortem technique that your client could perform to determine whether a dead lamb:
1. Was born alive or still-born
2. Managed to get up is feet and walk
3. Died before or after all its reserves of energy were exhausted
1. Lungs inflated or not
2. Has "slippers" on
3. Amount of BAT
30
List the 3 major causes of perinatal lamb mortality
1. Starvation, mismothering, exposure (SME)
2. Dystocia
3. Predation
31
List some of the minor causes of perinatal lamb mortality
- Death in utero/prematurity
- Infectious diseases
- Trauma --> stood on by ewe
- Trace element deficiencies
32
Describe how you will investigate perinatal lamb loss
- Estimate losses
- History: nutrition, trace element supp, lambing paddock, pre-joining exams of ewe, breed, age
- Lamb PM: weight, sex
33
What may indicate hypothermia in a PM exam?
Yellow subcut oedema of extremities
34
Explain primary vs secondary predation
Primary: lamb appears normal but suffered fatal injury
Secondary: lamb is abnormal --> more susceptible
35
Describe the effects of Selenium, Copper and Iodine deficiencies
Selenium: white muscle disease, heart/skeletal muscle lesions
Copper: swayback - enzootic ataxia, hypomyelinogenesis of CNS
Iodine: goitre, subclinical (NO foetal stores of iodine)
36
Describe some of the clinical signs of iodine deficiency
- Small woolless lambs, weak, susceptible to cold stress
- High incidence of stillbirths
- Goitre
- Goats more susceptible
37
Describe the treatment and prevention of iodine deficiency
- Lugols iodine to lambs for 15d
- Shelter
- Potassium iodine drench ewes 8 and 4 wks before lambing
- Iodised salt blocks
- Prevent ewes grazing crops containing goitrogens (white clover, Brassica)
38
Describe some of the ways in which you can control and decrease neonatal lamb mortality
- Ewe health: BCS 3-3.25
- Scan ewes to ID multiple preg
- Good lambing paddocks --> shelter, feed
- Predator control
- Avoid disturbing lambs
- Cull ewes that can't rear lambs
- Cull ewes w/ mastitis
- Adjust lambing time
- Supp w/ melatonin
39
MCQ: The desirable minimum scrotal circumference of a normal 2-year-old Merino ram is:
A. 26 cm
B. 28 cm
C. 30 cm
D. 32 cm
E. 34 cm
D. 32 cm
40
MCQ: Brucellosis in rams:
A. is caused by Brucella abortus
B. is transmitted by homosexual activity (ram to ram)
C. is usually associated with abortions in maiden ewes
D. is successfully prevented by vaccination
E. is commonly diagnosed by culture of semen
B. is transmitted by homosexual activity (ram to ram)
41
Briefly describe your approach to perform a ram breeding soundness examination.
- History: breed, age, ID, previous illness, recent transport
- General exam: 5T (toes, torso (BCS), teeth (age, wear), testicle, tossle (penis)
- Genitalia exam: palpate scrotal skin, scrotal contents, prepuce and penis
- Other tests: semen evaluation, ultrasound of genitalia, evaluate libido
42
Outline the aetiology, treatment and management of pizzle rot in wethers.
Aetiology:
- Corynebacterium renale
- grazing lush, clover dominant pastures (protein-rich) --> increased urea in urine --> ammonia --> damage skin of pizzle
Treatment
- isolate affected animals
- restrict diet
- acidify urine
- antiseptic on pizzle
- slit pizzle
Prevention
- ringing
- restrict diet
- testosterone injection: increases wool fibre diameter
43
Describe the main epidemiological features and diagnostic methods of Ovine Brucellosis.
Epidemiology
- bacteria enter bosy through any mucous membrane
- venereal disease from infected semen
Diagnosis
- history
- testicular palpation
- blood test --> complement fixation test, ELISA, gel diffusion test
- semen culture
- microscopic exam of semen
44
Which bacteria causes knob rot in rams?
Trueperella pyogenes
45
What are the three methods of eradicating Brucellosis ovis?
1. Test and slaughter: better for large flocks or if valuable rams, expensive
2. Total replacement: good for small flocks, high cost
3. Two flock system: buy new rams and separate from infected, hard to manage
46
MCQ: which one of the following combinations of anthelminthics is the least likely to show resistance when used to control Telodorsagia (ostertagia) circumcincta in sheep in south east SA.
A. albendazole, levamisole
B. fenbendazole, levamisole
C. albendazole, levamisole, abamectin
D. albendazole, levamisole, abamectin, closantel
E. albendazole, levamisole, abamectin, derquantel
E?
47
MCQ: Haemonchus contortus is most commonly found in the?
A. Omasum
B. Abomasum
C. Duodenum
D. Jejunum
E. Large intestines
B. Abomasum
48
MCQ: use of which of the following products is most likely to cause the development of anthelmintic resistance by sheep nematodes?
A. Moxidectin injections
B. Levamisole oral drench
C. Ivermectin oral drench
D. Napthalophos oral drench
? Moxidectin as it is long-acting
49
Outline THREE (3) important practices a producer can implement to slow down the development of drench resistance.
1. Don't under-dose
2. Regular drench resistance testing
3. Use combination products
50
What are the most important worms for winter high rainfall areas of southern Australia?
- Telodorsagia circumcincta
- Trichostrongylus
- Occasionally Nematodirus
51
Compare merino ill-thrift vs prime lamb ill-thrift
Merino: survival to 1yo should be >95%, should be 45% of mature BW by start of 1st winter
Prime-lamb: inadequate growth to meet target dates, meat sheep should grow at 150g/day, if ewes are going to lamb at 1yo, must be 75% of mature BW by 7mths
52
Describe some weaner management strategies
- Do not wean before 30 days or 8-10kg
- For max survival, should be 15kg
- Wean lambs 6-10 wks before ewes next joined
- Wean abruptly
- Drench at weaning
- Wean onto GREEN PASTURES
53
How much green pasture do merino weaner lambs need?
800-1000 FOO kg green pasture w/ 10 MJ ME/Kg DM and 15% protein
54
How much green pasture do meat weaner lambs need?
1200kg FOO 10 Mj ME/Kg DM and 17% protein
55
How do sheep get Yersiniosis and what are the signs?
Usually when prior damage to gut wall and animal stressed. Faecal-oral trans
- Most show no signs
- Profuse watery diarrhoea
- Morbid. 20-70%
- Mort. 2-5%
- PM: ulcerative enterocolitis with micro-abscesses in GIT wall and mesenterial LN
56
How can you treat Yersiniosis?
- Treat underlying cause: usually worm
- Treat with AMS --> oxytet
57
What would be the DDx for scouring in weaner sheep?
Yersinia, worms, coccidia, salmonella
58
How can you determine a sheep has coccidiosis? How will you treat?
- Diarrhoea, ab pain, weight loss
- Haemorrhagic enteritis, ulceration, mucosal thickening, characteristic white plaques
- Presence of many oocysts
- Treat with Toltrazuril, Sulphadimidine
- Prevent by reducing stress
59
What causes Eperythrozoonosis? What are the signs?
Mycoplasma ovis
- spread by biting/blood sucking insects
- anaemia, fever, jaundice
- splenomegaly, haemoglobinuria
60
What are the clinical signs of Selenium deficiency?
- Selenium responsive ill-thrift
- White muscle disease: non-inflam degen or necrosis of muscles
- Ewe fertility
61
What are the signs of white muscle disease as a result of Se deficiency?
- Heart failure
- Resp distress
- Weakness, stiffness
- Arched back
- Recumbency
- Cattle: disruption of scapular girdle (bulldog look)
62
How can you treat Se deficiency?
- Supp pre-lambing
- Oral drenches: 0.1 mg Se/kg LW, sodium selenate
- Injectable: long-acting (barium selenate) 1mg Se/kg LW 4 wks before mating or short-acting (sodium selenate) to lambs at marking time
- Intraruminal pellets
- Topdress pastures
63
What are the clinical signs of Cobalt deficiency?
- Decreased GR and wool growth
- Anorexia
- Ill-thrift
- Watery discharge from eye
- Photosen
- Anaemia
- White liver disease
64
How can you treat Cobalt deficiency?
- vit B12 injection SC in neck (won't work against phalaris staggers)
- Cobalt pellets
- Oral dosing
- Topdressing
65
Describe the two types of Copper deficiency
Primary: dietary levels insufficient --> soil or plant deficiency
Secondary: ruminal abs inhibited by high levels of Mo, Fe, S, Mn
66
Describe the clinical signs of Copper deficiency
- Enzootic ataxia: hypomyelinogenesis of motor neurons
- Bone fragility
- Fleece derangement: loss of crimp, banding of pigmented wool
- Ill- thrift +/- anaemia
67
How can you treat and prevent copper deficiency?
- Cu in fertiliser
- Cu oxide bullets
- Cu EDTA injection: 0.5-1mg/kg LW
- Cu sulphate drench
- Loose licks and blocks
68
Name two plants that can cause copper toxicity
Heliotropium, Paterson's curse
69
What are the signs of acute and chronic copper toxicity?
Acute
- ab pain
- red-brown urine
Chronic
- depressed, off-feed
- red-brown urine
- severe jaundice
70
How can you prevent Ricketts?
1. Ca supp
2. vit D injections
3. Spike grain with Ca
71
Aside from leaving a paddock destocked, outline TWO (2) other methods you could use to make a paddock low worm-risk?
1. Graze paddock with different animal species e.g cattle or horses
2. ? put less susceptible animals on paddock
72
What is worm resistance?
Sheep may be resistant to worms and prevent them from establishing resulting in lower egg counts
73
Outline the steps you would undertake to develop an effective and sustainable worm control program for a self-replacing Merino wool farmer in a winter rainfall area such as Western Victoria.
- Determine important worms
- Strategic drenching: 1st summer in nov/dec, 2nd in feb
- Weaning drench to lambs
- Quarantine drench new stock
- Monitor WEC
- Breed worm-resistant sheep
- Maintain good nutrition and BCS
74
When would you routine drench sheep in summer rainfall regions with Barbervax?
- Oct/Nov
- Weaning drench to lambs
75
When should you routinely check WEC in summer rainfall regions?
- Prior to Oct/Nov drench
- Pre-lambing
- Ewes before shearing, lamb-marking, weaning
- Weaners every 4-6 wks (summer) or 6-8 wks (winter) after a drench
- Late Feb
- Mar-Oct: every 4-6 wks after significant rain that has follow up rain
76
MCQ: Which of the following treatment methods would you recommend to MOST likely achieve eradication of lice (Bovicola ovis) in sheep?
A. A backline application using Imidacloprid (Neonicotinoid)
B. Plunge dipping 4 weeks post shearing using diazinon (OP)
C. Hand jetting with ivermectin (ML)
D. Cage dipping 2 weeks post shearing using cyromazine (IGR)
E. Backline application using cypermethrin (SP)
A. A backline application using Imidacloprid (Neonicotinoid)
- resistance D and E
- B bad for humans
- C hand jetting not most effective
77
MCQ: All of the following statements regarding scabby mouth (contagious pustular dermatitis) of sheep are true EXCEPT:
A. It is common
B. It is usually diagnosed on the basis of clinical findings
C. It has zoonotic potential
D. It can be eliminated in a flock by the use of systemic antibiotics
E. It produces good immunity in individuals against subsequent infection
D. It can be eliminated in a flock by the use of systemic antibiotics
(it is a virus)
78
MCQ: Dermatophilosis (lumpy wool) is most likely spread by
A. Lice when they infect other sheep
B. Penning wet sheep in close contact when they have short wool
C. Working sheep in dusty yards
D. Failure of shearers to disinfect their combs and cutters after shearing infected sheep
E. Contaminated vaccinating equipment
B. Penning wet sheep in close contact when they have short wool
79
MCQ: A client who runs a self-replacing Merino wool flock is concerned about the presence of cheesy gland amongst her sheep. Cheesy gland in sheep in Australia:
A. is caused by Mycobacterium pseudotuberculosis
B. responds well on parental penicillin treatment
C. is spread by flies during warm and wet weather
D. is usually self-limiting with sheep recovering without treatment within 2-3 weeks
E. can be prevented by vaccination
E. can be prevented by vaccination
80
A client seeks your advice on the use of caseous lymphadenitis (CLA, cheesy gland) vaccine in her First-cross ewe flock. She currently runs 3000 cross-bred ewes which are purchased on an as need basis. Her chief objective is to supplement income from wool by the sale of lambs.
Discuss the epidemiology and control of CLA and develop a suitable vaccination program for this particular property.
- lambs being sold don't need vacc
- ewes that are kept should be vaccinated with clostridial x2, 4 - 6wks apart, annual booster prior to shearing
81
How can you diagnose, treat and prevent infections with scabby mouth?
Diag: clinical signs
Treat: spontaneous recovery within 3-4wks
Prevention: live vacc on bare area of skin
82
How can you treat and control facial eczema/photosensitisation
Treatment:
- treat underlying cause
- remove from toxic pastures
- keep in shed and feed low protein diet
- early culling
Control
- spore count after high risk weather
- spray pastures with fungicides
- drench with zinc oxide slurry to decrease liver damage
- breed for resistance
83
How can you diagnose lice infestations?
10 - 20 partings per side on min. 10-15 sheep that show signs (rubbing, biting at wool, ragged appearance, discolouration)
84
How can you eradicate lice?
- complete musters
- avoid split shearing
- avoid treating ewes with lambs at foot
- quarantine new sheep
- apply chemical correctly
- treat all sheep at shearing
85
What bacteria is fleece rot caused by? What are the typical signs?
Pseudomonas aeruginosa
- canary stain, yellow banding
- mostly on shoulders, withers, back
86
How can you treat and prevent fleece rot?
Treat: usually self-limiting
Prevention
- change shearing time (short wool in late spring, summer)
- genetic selection
87
It is October (autumn). You are doing a locum in a mixed practice in the UK. 17 sheep that are part of a flock of 70 animals are presented to you with signs of pruritis, alopecia and crusting, with patches of wool loss particularly over the shoulders, flanks and back. There is also matting and a yellow to brown discolouration of he fleece. Alopecic areas are variably erythematous, excoriated and heavily crusted. Rubbing the lesions evokes a ‘nibbling’ response in most individuals
1. What is your DD for sheep with these clinical signs?
2. How would you confirm the diagnosis?
3. How should these sheep be treated?
1. Sheep scab, dermo, lumpy wool, mycotic dermatitis
2. Skin scrapings looking for Psoroptes ovis
3. Injectable MLs
