Diarrhoea in Adult Cattle Flashcards
What are the common Salmonella serotypes?
S. Dublin and S. Typhimurium
What are the clinical signs of salmonella?
- Diarrhoea, often pyrexic/systemically ill
- Other features
- Carrier state
- Abortions
- Septicaemia/pneumonia/polyarthritis/ear tip necrosis in calves
What is the pathogenesis of salmonella?
- Ingestion
- Faecal-oral route
- Survival in rumen and abomasum
- Colonisation and invasion of intestinal epithelium
- Clinical signs often enteritis but may include systemic signs
What is the “salmonella cycle?”
What mixed infection is common with salmonella?
F. Hepatica
What is the most common cattle source of infection?
- Source of infection for herds is usually bought-in cattle
- Or contaminated feed/pasture/water?
How can salmonella infections happen in a clsoed herd?
- Shedding of the organism activated by stress
- Calving, weather, transport
How can we diagnose salmonella? (3)
- Can be difficult
- Clinical signs/PM not unique
- Enteritis
- Faecal samples
- Sample prior to antibiotics!
- PM samples of mesenteric Lnn
- Faecal samples
- Abortion
- Foetus, placenta
- Infected herds: slurry samples?
- Screen for fluke!
How can you treat salmonella?
- Antibiotics important?
- Prevent systemic disease
- Longer carrier state
- Select for resistant strains
- Culture and sensitivity important!
- Resistant strains!
- S. typhimurium DT104
How can we use antibiotic therapy in adults and calves?
- Adult cattle
- Amoxicillin, Sulphadiazine & trimethoprim (TMPS)
- Systemic route (IM, 5 days)
- Oral antibiotics interfere with rumen flora in adults!
- Systemic route (IM, 5 days)
- Amoxicillin, Sulphadiazine & trimethoprim (TMPS)
- Calves
- Oral antibiotics pre-weaning
- Will kill all of the good bacteria in the rumen in the adult but in calves they do not have the rumen flora so can be given it orally
- Consider sensitivity testing results?
- Oral antibiotics pre-weaning
What vaccine is available for salmonella?
- Dead vaccine available
- Bovivac S: S. dublin and S. typhimurium
- Licensed in the face of an outbreak
- Serological and colostral immunity
- 2 doses 21 days apart, whole herd
- Calves from 3 weeks of age
- Boost prior to calving
How can you prevent salmonella? (7)
- Salmonella can persist in environment for years
- Closed herd
- Carrier animals (often calves)
- Disinfection protocols
- Prevent concurrent liver fluke infection
- Wildlife biosecurity
- Feed and pasture contamination
- Clean water source (mains)
What is winter dysentery?
Winter dysentery is the term usually given to a characteristic syndrome of diarrhoea and mild milk drop (reduction in yield) almost always seen in groups of animals.
What is the aetiology of winter dysentry?
The causal agent is thought to be a coronavirus with a tropism for GI and respiratory tracts
What are the clinical signs of winer dysentry?
Self-limiting profuse diarrhoea (usually dark in colour, often described as “explosive”!). Usually accompanied by a reduction in milk yield (often of 10-30%, depending on stage of lactation). Occasionally causes colic in severely affected individuals.