FAC22: Diarrhoea in Adult Cattle Flashcards
What is the physiological cause of diarrhoea?
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
What are the Bacteria and viral causes of diarrhoea?
Johne’s
Salmonella
Winter dysentery
BVD
Malignant catarrhal fever
Toxic metritis/mastits
What are the toxins that cause diarrhoea?
Ragwort
Acorns
Lead
Mercury
Copper
Nitrite
What parasites cause diarrhoea?
Fluke
Parasitic gastroenteritis
Coccidia
What nutritional factors cause diarrhoea?
Acidosis
Excess dietary protein
Rapid dietary change
What causes winter dysentery?
Coronavirus
Who gets winter dysentery?
Housed dairy cows
How do you treat winter dysentery?
Generally self-limiting
Symptomatic therapy - oral fluids, spasmolytics
Describe the faeces of a cow with winter dysentery.
Profuse often bloody, watery.
Can Salmonellosis cause abortion?
Yes.
What are the causative agents of salmonellosis? Which one is zoonotic? Which must be reported to AHO?
Salmonella Dublin
Salmonella Typhimurium - zoonotic
BOTH
How do you confirm salmonellosis?
Fecal sample
Describe the pathogenesis of salmonella.
Evade abomasum
Multiply in Peyer’s patches
Effects the immunosuppressed
Results in enteritis > septicemia > abortion
How do you treat salmonellosis?
Antibiotics: florfenicol, trimethoprim-sulphadiazine, potentiated amoxicillin, fluoroquinolones
Supportive therapy
Fluids
NSAID
Nursing
Describe the faeces of a cow with salmonellosis.
Profuse watery
What is another name for Johnes Disease?
Paratuberculosis
What is Johnes Disease?
A chronic granulomatous bacterial enteritis of adult cattle, sheep, and goats caused by Mycobacterium Avium Paratuberculosis (MAP)
Describe the faeces of a cow with Johne’s
Watery and possibly bubbly
How does Johne’s get into a herd?
Replacement heifers or bulls, poor biosecurity, infected slurry, wildlife reservoirs (rabbits and deer)
How does Johne’s spread in a herd?
Faeces, colostrum, milk
Why is Johne’s so hard to get rid of?
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
How do you manage Johne’s in an infected herd?
- Clean calving pens
- Clean food and water troughs
- Don’t share or pool colostrum
- Snatch calves at birth
- Don’t spread slurry on land grazed by youngstockDispose of bedding from infected beasts
- Good biosecurity
- Quarantine arrivals
- Test during quarantine
- Buy from low-risk farms
- Test all animals >2y old annually
- Remove all positives
- Do not keep heifer from replacements from positives
Describe the pathogenesis of Johne’s.
- 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
