Dealing with diarrhoea – Part 2

Calf diarrhoea can cause a greater financial loss than any other disease-related problem.

Dealing with diarrhoea – Part 2
- Advertisement -

Diarrhoea (purging, scours) in calves can prove fatal, as these animals are hit hard by the dehydration and loss of body salts. The younger the animal, the greater the chance of death. Eight causes of diarrhoea are described below.

Rotavirus diarrhoea

This can occur within 24 hours of birth. There will be severe drooling and watery diarrhoea, with the faeces varying in colour from yellow to green. The calves will not eat and the death rate may be as high as 50%.

Coronavirus diarrhoea
This occurs in calves over five days of age. Initial signs may be the same as in rotavirus, but later the faeces may contain clear mucus similar to the white of an egg. Mortality is low, at 1% to 25%. 

Bovine virus diarrhoea (BVD)
BVD begins two to three days after exposure to the germ and may last for a long time. Signs include ulcers on the tongue, lips and in the mouth. The condition can be controlled by vaccinating all replacement heifers one to two months before breeding. Pregnant heifers should not be vaccinated, however; consult your vet before starting a vaccination programme.

- Advertisement -

Colibacillosis (Eschericia coli)
E. coli is a major cause of diarrhoea in young calves. It causes inflammation of the intestinal lining – enteritis – and can lead to death within hours. A less severe form is usually characterised by diarrhoea with progressive dehydration. Colibacillosis lasts for two to four days; its severity will depend on the calf’s age. E. coli is excreted in the faeces and can contaminate kraals, paddocks and even water supplies. It can be difficult to control after a severe outbreak in the herd.

Early detection and treatment of scours help to prevent new cases. It is also important to isolate affected animals. Ask your vet or animal health technician for advice on remedies; these are usually mixtures of sulphonamides and antibiotics.
Animals should be vaccinated twice: at six weeks and again at three weeks before calving. However, for the vaccine to be effective, it is essential that the calves get colostrum in the first few hours of life.

This is a bacterium that produces a poison called an endotoxin. Calves are usually affected at six days of age or older. Symptoms include diarrhoea, the presence of blood and yellow clots in the faeces, and a high temperature.
Bacteria multiply in the intestine and many reach the bloodstream, causing infection and sudden death. Tick-borne diseases and underfeeding make calves more vulnerable to salmonella. Consult your state vet for advice on medication.

Enterotoxaemia (pulpy kidney)
Enterotoxaemia usually starts quite suddenly. Affected animals become listless and kick at their abdomen. It is associated with a change in the weather, a change in the feed, or management practices that cause the calf to nurse for longer than usual. The hungry calf may drink too much milk, which encourages the growth of toxins in the gut. The disease can be controlled by vaccinating cows 60 and again 30 days before calving.

This parastic disease occurs in calves three weeks and older, usually following stress, poor sanitation, overcrowding or sudden changes of feed. A typical sign of coccidiosis in young calves is diarrhoea with faeces smeared over the rump as far around as the tail will reach. The symptoms are diarrhoea with slimy and bloody faeces, extreme weight loss and weakening. The affected calves strain excessively when they defaecate. Your vet will advise you about treatment with appropriate remedies such as sulphonamides and Amprolium.

Nutritional diarrhoea
This is caused by anything that disrupts the normal nursing pattern, such as storms, strong wind or the mother’s temporary absence. When the hungry calf gets the opportunity to nurse, the cow’s udder may contain more milk than normal and the calf may take in excessive quantities, resulting in nutritional scours. Milking the cow to limit the milk intake by the calf usually clears up the problem.

The treatment of the various forms of diarrhoea is very similar. This should be directed towards correcting the loss of fluids (dehydration), acidosis (acidity) and loss of salts. Calves may be given milk diluted with an equal quantity of clean water. Antibiotic and/or sulphonamides treatment can be given simultaneously with the treatment for dehydration. Salt powders (also called electrolyte powders) can also be mixed with water for oral administration.

If these powders are unavailable, oral preparations can be made on the farm. Combine 1 tablespoon baking soda, 1 teaspoon salt and 250ml of 50% dextrose (or light Karoo syrup), and add enough water to make 5l. You can also combine two-and-a-half dessertspoons of salt, two-and-a-half dessertspoons of baking soda, and eight dessertspoons of glucose, adding water to make 2l.

Source: Diarrhoea in cattle, by D Luseba, Directorate Agricultural Information Services, department of agriculture, in co-operation with ARC-Institute for Tropical and Subtropical Crops.