Calf diarrhoea Flashcards
What are the five agents that cause majority of calf scours?
*Rotavirus
*Coronavirus
*Cryptosporidia
*K-99 E.coli
*Salmonella
How does rotavirus + coronavirus cause diarrhoea?
*Damage intestinal lining - tips of intestinal villi
*Malabsorption of milk
=Fluid + electrolyte loss = dehydration, acidosis + death
How does E.coli cause diarrhoea?
*Enterotoxigenic E.coli - toxin causes hypersecretion of water + electrolytes from cells
Why is salmonellosis different? What are the clinical signs?
*Pathogenic for cows + calves
*CS = diarrhoea, pyrexia, abortion, pneumonia, sudden death
What are different sources of agents?
*Adult cows
*Other calves
*Environment - esp cryptosporidium (resistant oocyst)
What are host defences in diarrhoea?
*Passive immunity = IgG + IgA
*Healthy gut flora = suppress growth of pathogens
What are calf factors of diarrhoea?
*Colostrum status
*Stress, chilling
*Nutrition
How can you prevent calf scour?
*minimise exposure
*maximise protection
*minimise stress
How can you minimise exposure in a herd?
*Calve outside / clean calving area
*Tight calving period, flow system
*Isolate sick calves
How can you maximise protection within a herd?
*Vaccinate dam - Rotavec / E.coli
* Make sure there’s good passive transfer - 2-3litres of colostrum within first 2 hours
*Adequate cow nutrition
When would you vaccinate the dam?
*Roughly 30days prior to calving
-calves must suckle vaccinated dam
What are sandhills calving systems?
*Move non-calved cows to new pasture for calving - roughly every week
-eliminates pathogen multiplier effect
*Need multiple pasture blocks
When is coccidiosis seen? What are the causes + CS?
*Seen in older calves (>21days)
*Poor hygiene - near feeding troughs
*CS = dark scour +/-blood, Tenesmus (straining to shit)
How would you diagnose + treat coccidiosis?
*Dx = Faecal oocyst count
*Tx = Sulfonamides, Diclazuril
What age of calves does necrotic enteritis affect? What are the clinical signs?
*Affects 2-6month old suckler calves
*CS = Pyrexia, pale MM, leucopenia, thrombocytopenia
*PM = necrotic lesions of gut + resp tract
