Diarrhoea Flashcards
What diseases are considered ‘production diseases’?
Mastitis, respiratory diseases, lameness
List some bacterial causes of diarrhoea in cattle?
- Salmonella
- Bovine Johne’s
- Yersinia
- Campylobacter jujuni
- Clostridium perfringens (Type A)
Calves:
- E.coli
- Salmonella
- Clostridium difficile
List some viral causes of diarrhoea in cattle:
- Bovine viral diarrhoea
- Malignant catarrhal fever
- Bovine adenovirus (emerging disease in NZ)
Calves:
- Rotavirus
- Coronavirus
List some parasitic causes of diarrhoea in cattle:
- Ostertagia ostertagi
- Cooperia
- Haemonchus
- Eimeria
Calves:
- Cryptosporidium
- Giardia
List some nutritional causes of diarrhoea in cattle:
- Copper deficiency
- Acute copper toxicity
- Cobalt deficiency
- Selenium deficiency
- Lush, rapidly growing pasture
Calves:
- Overfeeding
- Indigestion
- Poor-quality milk replacer
- Poorly stored colostrum
List common toxic causes of diarrhoea in cattle:
- Aresnic
- Salt
- Mercury
- Nitrate/Nitrate
- Molybdenum (secondary copper deficiency)
- Mycotoxins
List some non-enteritis causes of diarrhoea in cattle:
- Diseases of the forestomachs
- Toxaemia
- Hepatitis
- Peritonitis
- Congestive heart failure
- Renal amyloidosis
What are important history Q’s to ask in a case of diarrhoea?
- diet / ration
- appetite
- worming
- vaccination status
- introduction of new animals
What is the most common disease associated with acute diarrhoea in adult dairy cows?
Salmonellosis
(esp. Salmonella typhimurium)
Describe the pathogenesis of salmonella:
Infection by ingestion -> bacteria invade enterocytes -> colonise distal small intestine (ileum) and colon -> produce enterotoxins -> damage to villi -> inflammation and necrosis of the mucosa -> malabsorption and maldigestion
Carrier state: organisms survive in macrophages, lymph nodes, gall bladder and bile ducts
Why does magnesium oxide supplementation increase the risk of salmonellosis?
It increases the pH of the rumen (alkalinises) which allows salmonella to thrive
List some risk factors for salmonellosis:
- overcrowding
- parturition (lowered immunity)
- sudden dietary changes
- poor BCS
- magnesium oxide supplementation
- effluent spread on pastures
- after major surgery
What is shown in this image?
Fibrin cast mucosa in diarrhoea
What is effective colostrum management?
Feed colostrum ASAP and vaccinate mature animals prior to calving (where possible) to increase antibody production
What is the predominant species causing yersiniosis?
Yersinia pseudotuberculosis
Which animals are ost likely to get yersiniosis?
Usually yearlings - seen in the best animals in the mob
Describe the diarrhoea seen in a case of yersiniosis:
What other disease causes similar diarrhoea?
Green-brown feaces (non-haemorrhagic) without a bad odour
Similar to diarrhoea seen in parasitism
What are the presenting signs of Johne’s disease?
- lowered milk production
- chronic weight loss, despite a normal appetite
- diarrhoea (‘hose-pipe’ in advanced disease)
This cow has been suffering chronic weight loss, despite a normal appetite. Milk production has decreased and diarrhoea has been intermittent, though increasing in frequency over time. It now looks like this:
What is your diagnosis?
Bovine Jone’s Disease
What age group is affected by enterotoxigenic e.coli (ETEC) infection?
Only occurs in the first 4 days after birth
The animals in these images have high fever, profound depression and anorexia and generalised lymphadenopathy to accompany the following lesions. What is your diagnosis and how should they be treated?
Malignant catarrhal fever - euthanasia (no recovery)
What age group are typically affected by coccidiosis?
4 weeks - 12 months
This calf is producing profuse, dark, blood-tinged diarrhoea. The diarrhoea is malodourous and the calf has been excessively straining.
What is a likely diagnosis?
Coccidiosis
What is the most common cause of calf diarrhoea in Australasia?
Rotavirus
