Scour is the most common cause of disease and death in calves before weaning. Most cases are seen around 2 weeks after birth, but disease can occur anywhere between 24 hours and 3 weeks.

Affected calves show 3-4 days profuse yellow/white diarrhoea during which there is marked weight loss with increasing dullness and lethargy. Calves can become very weak and have trouble rising. Faeces becomes progressively watery and commonly hind quarters are stained yellow or hair is lost. In terminal stages, respiratory rate increases, eyes become sunken, saliva overflows from the mouth and heart problems can occur.

Gazette & Herald: Ensure calves receive good quality colostrum from their dam within6 hours of birthEnsure calves receive good quality colostrum from their dam within6 hours of birth

Scour may be nutritional or infectious. The main viral causes are Rotavirus and Coronavirus but bacteria such as E. coli and protozoan parasites like Cryptosporidia also cause infectious scour. Regardless of the cause, rehydration is the key to survival. When you first see a scoured calf, it will have been losing fluids into its gut for 12 hours already! The best way to achieve rehydration on farm is with additional feeds of electrolyte solution. These have a much lower energy content than milk so must always be given in addition to normal milk feeds.

If there is no improvement or clinical signs worsen (deep sunken eyes, cold ears/nose, unwilling to suck or stand) despite rehydration on farm then veterinary attention should be sought as intravenous fluids may be required to save the calf.

Depending on the cause, there may be additional treatments which can be given to aid recovery and prevent disease in other calves. A 10 minute, in house test on a faecal sample can be used to detect some of the more common infectious causes of scour and direct treatment protocols.

Gazette & Herald: Using vaccines pre-calving can boost antibody levels in colostrum at calvingUsing vaccines pre-calving can boost antibody levels in colostrum at calving

Ensuring adequate colostrum intake is essential to give calves the best start in life. A calf is born without the circulating antibodies required to provide immune protection. Antibodies cannot pass through the placenta so are not transferred from cow to calf during gestation. Consequently, it is essential that a calf receives enough of these antibodies from the dam’s colostrum as soon as possible after birth to provide protection against infectious diseases during the first months of life. Straight after birth, antibodies can easily pass through the calf’s intestine and into the blood, but this ability rapidly reduces to almost zero by 24 hours. Current guidelines suggest that calves should receive 3-4 litres, or at least 10% of their bodyweight of colostrum within 2-4 hours of birth. Whether a calf remains healthy or gets scour is determined by a balance between resistance of the calf to infection and the level of infection the calf is exposed to.

Colostrum quality can be maximised by vaccinating cows for infectious causes of scour between 12 and 3 weeks pre-calving. This reduces the incidence, severity and shedding of Rotavirus, Coronavirus and E. coli. by enhancing the levels of antibodies in colostrum.

For more information or to discuss cases on your farm, please phone the practice on 01751 469343 or contact

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