FAC22: Diarrhoea in Adult Cattle

Question 1

What is the physiological cause of diarrhoea?

Answer 1

Increased osmolality

• Change in diet
• Access to milkd
• Liver damaged

Increased secretion

Decreased absorptive area

• Thickening of GIT
• Desctruction of vili/epithelial lining

Deragned motility

• Vagal indigestion
• Bloat
• Intussusception

Question 2

What are the Bacteria and viral causes of diarrhoea?

Answer 2

Johne’s

Salmonella

Winter dysentery

BVD

Malignant catarrhal fever

Toxic metritis/mastits

Question 3

What are the toxins that cause diarrhoea?

Answer 3

Ragwort

Acorns

Lead

Mercury

Copper

Nitrite

Question 4

What parasites cause diarrhoea?

Answer 4

Fluke

Parasitic gastroenteritis

Coccidia

Question 5

What nutritional factors cause diarrhoea?

Answer 5

Acidosis

Excess dietary protein

Rapid dietary change

Question 6

What causes winter dysentery?

Answer 6

Coronavirus

Question 7

Who gets winter dysentery?

Answer 7

Housed dairy cows

Question 8

How do you treat winter dysentery?

Answer 8

Generally self-limiting

Symptomatic therapy - oral fluids, spasmolytics

Question 9

Describe the faeces of a cow with winter dysentery.

Answer 9

Profuse often bloody, watery.

Question 10

Can Salmonellosis cause abortion?

Answer 10

Yes.

Question 11

What are the causative agents of salmonellosis? Which one is zoonotic? Which must be reported to AHO?

Answer 11

Salmonella Dublin

Salmonella Typhimurium - zoonotic

BOTH

Question 12

How do you confirm salmonellosis?

Answer 12

Fecal sample

Question 13

Describe the pathogenesis of salmonella.

Answer 13

Evade abomasum

Multiply in Peyer’s patches

Effects the immunosuppressed

Results in enteritis > septicemia > abortion

Question 14

How do you treat salmonellosis?

Answer 14

Antibiotics: florfenicol, trimethoprim-sulphadiazine, potentiated amoxicillin, fluoroquinolones

Supportive therapy

Fluids

NSAID

Nursing

Question 15

Describe the faeces of a cow with salmonellosis.

Answer 15

Profuse watery

Question 16

What is another name for Johnes Disease?

Answer 16

Paratuberculosis

Question 17

What is Johnes Disease?

Answer 17

A chronic granulomatous bacterial enteritis of adult cattle, sheep, and goats caused by Mycobacterium Avium Paratuberculosis (MAP)

Question 18

Describe the faeces of a cow with Johne’s

Answer 18

Watery and possibly bubbly

Question 19

How does Johne’s get into a herd?

Answer 19

Replacement heifers or bulls, poor biosecurity, infected slurry, wildlife reservoirs (rabbits and deer)

Question 20

How does Johne’s spread in a herd?

Answer 20

Faeces, colostrum, milk

Question 21

Why is Johne’s so hard to get rid of?

Answer 21

Clinical onset is >2 years, at which point they already have a calf and gave it to that calf.

Tests are not sensitive in pre-clinical cows

Question 22

How do you manage Johne’s in an infected herd?

Answer 22

1. Clean calving pens
2. Clean food and water troughs
3. Don’t share or pool colostrum
4. Snatch calves at birth
5. Don’t spread slurry on land grazed by youngstockDispose of bedding from infected beasts
6. Good biosecurity
7. Quarantine arrivals
8. Test during quarantine
9. Buy from low-risk farms
10. Test all animals >2y old annually
11. Remove all positives
12. Do not keep heifer from replacements from positives

Question 23

Describe the pathogenesis of Johne’s.

Answer 23

• Ingestion of MAP
• Localises in ileum and gut-associated lymph nodes
• Phagocytosed by macrophages

Host may then become:

• Resistant: infection controlled - no clinical disease or faecal shedding
• Intermediate: subclinical disease an intermittent/persistent shedder
• Clincial: clinical disease and heavy shedder