Sheep Flashcards
Outline the clinical signs + gross pathology of abortion by Chlamydia (Chlamydophila) abortus in sheep.
(sep 2016)
- abortion often no premonitory signs, may get RFM
- PM (Gross) – placenta acutely inflamed, intercotyledonary allantochorion oedematous, thickened and leathery. Degeneration and necrosis of foetal cotyledons and thick yellow deposits on chorion
Outline the treatment + control of abortion by Chlamydia (Chlamydophila) abortus in sheep.
(sep 2016)
- Antibiotics – reduce (but not eliminate) abortions. As soon after 95-100 days gestation repeat every 10-14 days.
- Vaccination – Inactive vaccine preparation available for use during outbreak
- Isolate aborting ewes until discharges dried up
- Disposed of infected bedding and clean and disinfect
- Discourage foster lambs and do not use lambs as replacements
- Vaccination – based on risk High risk (yearly or biannually), low risk (ewes vaccinated just once)
- Biosecurity – keep closed flock
- EAE monitoring / accreditation can be undertaken.
Definitive diagnosis of abortion by Chlamydia (Chlamydophila) abortus in sheep.
(sep 2016)
Laboratory – Smears from placenta and foetal skin stained with modified ZN stain reveal intracellular inclusion bodies acid fast cocci
Serology – antibody in foetal fluid or precolostral lamb FAT or CF. Paired serology at abortion and 3-4 weeks later (rising titre)
Action for severe hypothermia (<37oC) in lambs
sep 2016
> 5hr old (feed, dry, heat, feed)
- if can’t lift head/swallow, glucose
- if can, stomach tube
- then dry lamb and place in heat box, before next stomach tube
<5hr old (dry, heat, feed)
- dry lamb, then warm in heat box, then stomach tube
If vigorous suck after stomach tube, return to ewe
Action for mild hypothermia (37-39oC) in lambs
sep 2016
dry and feed (no heat) stomach tube (no glucose)
If vigorous suck after stomach tube, return to ewe
Aetiologies of polyarthritis in 10-14d.o. lambs
sep 2016
Usually bacterial infection most likely Erysipelothrix rhusiopathiae.
(Others Histophilus spp. e.g. H.ovis, E. coli, Strep dysgalactiae, Strep spp, Staph, also Chlamydia, Mycoplasma!)
Causes of polyarthritis in 10-14d.o. lambs (NOT aetiology, but how are lambs infected?)
(sep 2016)
Bacteria enter through broken and softened skin
Likely to become infected soon after birth, via the umbilical cord
Also at tail docking, castration or marking and ear notching.
Erysipelothrix – ubiquitous survives in soil, faeces and water, also found in the tonsils and pharynx of ewe
Sheep, 11 clostridial diseases
sep 2016
C. perfringens
- Type A = enterotoxaemia, gas gangrene, sudden death
- Type B = LAMB DYSENTRY, enterotoxaemia
- Type C = STRUCK, enterotoxaemia
- Type D = pulpy kidney, enterotoxaemia
- C. tetani
- C. botulinum
- C. chauvoei = BLACK LEG/quarter
- C.novyi type B = BLACK DZ, infectious necrotic hepatitis
- C. sordelli = sudden death
- C. septicum = MALIGNANT OEDEMA/BRAXY
- C.haemolyticum = RED WATER DZ
Sheep, clostridial disease vaccination protocol
sep 2016
Ewe, 2-6wk pre-lambing
Maternal Ig lasts 12 wk protection
Can vaccinate lambs from 2w.o. (6-8wm usually) (2 injections, 4-6wk apart)
YEARLY BOOSTER
You are approached by a client who wishes to establish a flock of pedigree Texel sheep. What advice would you give regarding biosecurity in purchasing and running such a flock? 8 points
(sep 2016)
- Purchase sheep from known sources and health history and status to reduce risk of infection. Never bring in sheep without knowing their vaccination history
- Limit purchases to ewe lambs and gimmers not older sheep
- Quarantine all new arrivals for at least 30 days and preferable until after lambing. Opportunity to detect disease in sheep.
- Isolation of sheep prevents contact between groups of sheep after arrival on farm.
- Gives time for appropriate treatments Vaccination, hoof trimming, footbaths, SCOPS worming strategy
- Movement control includes vehicles, animals and people traffic.
- Cleaning and disinfection of vehicles and people entering the farm.
- Biocontainment: aim to prevent/reduce movement of infectious disease on the farm
Diseases widely present in national sheep flock
sep 2016
- Parasites (PGE, fluke, ectoparasites)
- Contagious causes of abortion (EAE, Salmonella Abortisovis, Campylobacter fetus subsp. fetus (intestinalis) C. jejuni)
- Foot problems (footrot, contagious ovine digital dermatitis)
- Respiratory tract (Sheep pulmonary adenomatosis,
- Other: caseous lymphadenitis, Scrapie, Maedi-visna, Johnes disease, orf, infectious keratoconjunctivitis
If giving Footvax vaccine to sheep, to treat for , which drug can never be given again in this animals lifetime?
1% cydectin, or 1% MOXIDECTIN
2% moxidectin or oral drench are fine!
5 Preventions of mastitis in dry period
sep 2016
- Dry Off: Abrupt cessation of milking,
- DCT – Aim to prevent new and cure existing mastitis infections. Antibiotic or teat sealant. Parenteral antibiotics may be used (useful Staph aureus mastitis) Choice based on SCC and clinical mastitis records
- Ensure diet is optimal so immune system is not compromised (Vitamin E/Se)
- Environmental cleanliness 60% of clinical mastitis in first 100 days after calving are due to infections picked up during the dry period.
- External teat sealents,
Drying off/dry period summary for feeding cows
sep 2016
3 stages
- Involution
- steady state
- colostrogenesis
6-8wk total
Ideally 2.5-3.5 BCS
Split into 2 blocks of 3 weeks (early and late)
Early
- reduce nutritional density of diet (hay/straw ideal)
- avoid getting too fat! (risk fatty liver –> ketosis –> reduced intake early lactation, dystocia)
- low Ca, high Mg and Ph
- selenium and biotin
Late (CRITICAL PERIOD)
- increase in energy and protein demand with foetus, but reduced DMI!
- increase energy density of food
- may need DUP source for high yielders (protein that survives rumen!)
NO WEIGHT LOSS, can gain up to 0.5BCS
3 reasons why nutrition is important during dry period in cows to prevent reproductive dz?
(sep 2016)
- avoid -ve energy balance
- poor nutrition can cause uterine disease (ca2+, mg, ph)
- avoid getting too fat, dystocia risk
3 ways prevention of lameness with nutrition in dry period in cows
(sep 2016)
- Nutrition to avoid toxaemias (metritis or mastitis) in early lactation associated with coriosis (laminitis)
- Foot trimming at dry off
- Nutrition: Biotin???