Diarrhoea in Farm animals Flashcards Preview

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Flashcards in Diarrhoea in Farm animals Deck (16):
1

3 factors involved

Pathogens
Calf Factors (immune system, stress)
Environment and Management

2

calf diarrhoea - pathogens

E. coli
rotavirus
Coronavirus
Cryptosporidium
Salmonella
mixed infections
(Coccidiosis)

3

rotavirus

Calves aged 1 – 3 weeks
High morbidity but low mortality
Duodenum and jejunum

4

coronavirus

Slightly older calves
? Slightly higher mortality
Ileum, caecum and colon

5

salmonella

Zoonosis- Public Health Issue
Culture of Salmonella is always significant
Any age of animal
Systemic illness and pyrexia
Species important in identifying source

6

coccidiosis

Slightly older weaned calves
May give blood stained faeces
May also be subclinical giving poor growth rate

7

diagnosis

Pathogens may be present in the absence of clinical disease
take faecal samples, not swabs
Sample healthy and affected animals
Send to competent laboratory
Bacteriology only is not sufficient

8

faecal appearance - calves

can be variable
notoriously unreliable

9

growing animal/adolescent - causes

Endoparasites
Rumen Acidosis
Salmonella
Nutritional
Post Weaning Scours

10

bovine viral diarrhoea virus (BVDV)

causes diarrhoea v.rarely

11

adult diarrhoea - causes

Johne’s Disease (MAP)
Sub Acute Rumen Acidosis (SARA)
Salmonella

12

Johne's disease

hosepipe diarrhoea
highly infectious
Mycobacterium avium subspecies paratuberculosis (MAP)
MAP

13

MAP 1

In clinical cases it causes severe diarrhoea and weight loss in adult cows
affected adult cows are infectious esp faeces
No treatment or cure – need to be culled on humane grounds
Potentially a zoonosis- MAP may be involved in Crohn’s Disease an inflammatory bowel disease in humans

14

MAP 2

Infection is usually acquired by youngstock but it only becomes clinical several years later
Control largely relies on preventing young animals becoming infected - faeces + infected colostrum
Subclinical Disease is hard to detect.
It is difficult to identify subclinically affected animals due to issues with Lab tests

15

MAP - prevention

Prevent calves getting infected
Prevent calves drinking infected colostrum from infected dam.
Avoid pooled colostrum
Prevent calves getting contaminated with adult faeces
Identification of subclinical infected adults difficult- lab test issues

16

diagnosis of MAP

Blood Test (ELISA) has Low Sensitivity but High Specificity
Many infected cows are not detected by blood test
A positive test is reliable
Milk test also available
Diagnosis is difficult when screening for infected cows
In clinically infected cows tests have a much higher sensitivity