Calf scour Flashcards
How can the calf’s immunity and resistance to disease be boosted?
- timing of feeding (first 6-12hrs)
- fed twice a day for first 3 wks of life
- colostrum storage in a lidded drum, stirred regularly and refridgerated or added preservation
- should be fed highest quality of colostrum
- new born calves need 2l of warm colostrum at first feed
How can minimising infectious pressure be achieved via housing?
Calf housing should be at least 20m from milking shed
Calves should be moved around shed as little as possible. Bobbies should be housed separately
Stocking density- calves need a minimum of 1.5m2. no more than 100 calves per shed or 20 per pen
Clean ,dry bedding replaced completely between seasons and refreshed during the season
Housing-should be dry and draught free with good drainage and ventilation systems. Partitions between calf pens should be solid
Define secretory diarrhoea
Electrolytes excreted, water follows
Define osmotic diarrhoea
Water drawn into intestinal lumen
Define malabsorption diarrhoea
intestinal lining damaged, can no longer absorb
what are the bacterial causes of calf scour?
salmonella, e.coli and campylobacter
Name the viral causes of calf scour
rotavirus, coronavirus
What are the parasitic causes of calf scour?
worms, cryptosporidia, coccidosis
Describe E.coli
- gram negative
- anaerobic rod bacteria
- common in calves <5 days
- signs= pyrexia, blood, wet mouth, distended abdomen, foul smelling
Describe salmonella
- mainly in calves <2 months
- via mothers milk or environment
- engulfed into intestinal lymphoid cells
- signs= pyrexia, blood, septicaemia, vascular necrosis
Describe rotavirus
age= 5-21 days adult immune carriers found in normal calves invade enterocytes signs- older, white scour, dehydrated
Describe cryptosporidium
age= 1wk-3months
- invagination of luminal membrane
signs= dehydration
Descrie coccidiosis
age= 3wks-3mths
rupture of enterocytes
signs- older/bloody scour, abdominal pain
adult immunity
When does necrotic enteritis commonly occur in beef calves?
7-10 weeks old
What are the consequences of scouring?
- dehydration
- azotaemia
- electrolyte losses
- acidosis
- hyperkalaemia
What percent of dehydration is considered fatal?
12-14%
What are the causes of metabolic acidosis?
intestinal loss of sodium
loss of bicarbonate into the gut
lactic acid production in shocked tissues
How does metabolic acidosis present in the calf?
Progressive depression Decreased suckle reflex Weakness and incoordination Inability to stand or sit up Coma
How would you know if there is D lactate?
absent suckle reflex
What should be given for mild acidosis?
lactated/acetate fluids
lactated ringers
What should be given for moderate acidosis?
lactated/acetate fluids plus 15g bicarb
What should be given for severe acidosis?
Lactated/acetate fluids plus 35g bicarb or bolus 10ml/kg of 8.4% hypertonic sodium Bicarb
What is the general rule of bicarb?
only admin it in calves older than 7 days that failed to respond to fluids only and also have clear signs of acidosis
What rate should bicarb be given?
80 ml/kg/hr
