sheep Approach to scour adult and lamb

History

·    What aged lambs affected? – neonates vs older lambs

·    Is lambing hygiene good? – poor hygiene = E. coli

·    Indoor or outdoor lambing? – indoor = risk of Haemonchus and protozoa

·    Recent weather conditions? – cold = N. battus, Jan-May time = incr. coccidiosis risk

·    How have the lambs been growing? – ill thrift/poor growth = coccidiosis, cryptosporidium, PGE

·    Any weight loss?

·    How are they managed, e.g. stocking density, age groups? – mixed aged groups = coccidiosis

·    Any dams affected? – salmonella (affects lambs + adults)

·    Any deaths? – clostridia

·    Appearance of scour? – bloody = coccidiosis, green + fetid smell = crypto, watery = N. battus

·    Any recent diet/management changes? – just put out to pasture = N. battus

·    Other clinical signs seen?

o  Abortion? – salmonella

o  Poor fleece quality? – PGE

Investigations

Full clinical exam of affected lambs:

·    TPR – pyrexic = cryptosporidium, E. coli

·    Examine head – hypersalivation (watery mouth) = E. coli

·    Assess hydration status – dehydration = N. battus, coccidiosis

·    Abdominal palpation – pot belly = E. coli, abdominal pain = cryptosporidium

·    Examine back end – straining + blood = coccidiosis

Further investigations:

·    If <7d take blood sample to check for FPT

·    McMasters of faecal sample - crypto

·    PM examination – haemorrhagic enteritis = clostridia

Treatment

·    Supportive treatment: replace fluid losses, keep warm, probiotics

·    Isolate

·    Antibiotics if pyrexic/systemically unwell

·    Coccidiostats

Causes

Neonates:

·    E. coli

·    Clostridium perfringens type B (lamb dysentery)

·    Salmonella

·    Rotavirus

·    Cryptosporidium (zoonotic)

Older lambs:

·    Rumen acidosis

·    Nematodirus battus

o  Most susceptible at 6w-4m (protected <6w by maternal antibodies), will develop immunity after first grazing season

·    Coccidiosis (Eimeria)

·    PGE – Teladorsagia, Trichostrongylus

Prevention

·    Good hygiene at lambing – clean/dry pens (bleach), change between ewes (prevent faeco-oral transmission)

·    Good colostrum management – 50ml/kg first 6h, 200ml/kg first 24h

o  Colostrum quality determined by ewe nutrition and BCS

·    Don’t mix age groups

·    Reduce stocking density

·    Vaccinate ewes against clostridial disease, can vaccinate lambs from 3w of age

·    Worming – benzomidazole for Nematodirus battus

·    If high risk pasture for N. battus (if lambs grazed previous year) then test regularly

History

·    What is their worming protocol?

·    What are they fed?

·    How many sheep affected?

·    Which animals affected?

·    Are they systemically well?

·    Other clinical signs?

·    What is the scour like?

·    Are they eating?

·    How long been going on for?

·    What season/time of year? – winter – kept indoors = easier spread of salmonella

·    Any abortions? – salmonella

Investigations

Clinical examination of affected animals:

·    TPR – pyrexic = salmonella

·    Auscultate rumen

·    Abdominal palpation – bloat = rumen acidosis

Further investigations:

·    Gram smears, culture, PCR – salmonella (gram -ve rods)

Treatment

·    Replace fluid losses

·    NSAIDs – reduce inflammation (meloxicam)

·    Amoxicillin for salmonella

·    Mineral oil drenches for rumen acidosis

·    Isolate affected animals

Causes

·    Rumen acidosis – too much grain/concentrate ® change in rumen acidity and bacteria species

o  Increased pH ® inflammation of rumen wall

o  Clinical signs: depression, off feed, bloat, scour, death

·    Salmonella

Prevention

·    Proper feeding management – correct amount of concentrates

·    Maintain closed herd, test animals before buying in