BEST PRACTICE ARTICLE: CALF SCOUR
Neonatal diarrhoea is the outward symptom of a variety of causes. Whilst infectious
organisms such as Coccidia, Cryptosporidium and viruses play a large part, management
aspects have an equally important role. Diagnosis can be a challenge as some of the
infectious agents are not always present and others may occur as an incidental finding. This
article will focus on a general approach to immediate treatment of the scouring calf.
However, to control future outbreaks it can be very useful to know the predisposing factors.
With changes in distribution category for some of the vaccines it is important that XL
practices need to be adding something else for the farmer other than a superficial fix of
vaccination.
Some infections cause diarrhoea by damaging the gut lining, leading to reduced absorption
of liquids. Treatment is aimed at supporting the calf while the infection clears and the gut
repairs itself.
Some basic figures are helpful to bear in mind. The normal daily fluid intake from milk for a
healthy calf is 5-7% of bodyweight: approximately 4 litres for a 60kg calf. However, this
figure may be an underestimate. When scouring, calves will lose an additional 5-10% (3-6
litres) of fluid and bicarbonate.
If unaddressed, these losses will result in dehydration and acidosis: in practical terms,
collapse and death. Therefore, fluid intake, including bicarbonate, of 7-10 litres daily needs
to be maintained in order to cope with these losses. This fluid has to be administered on a
little and often basis. Too frequently, calves will receive fluids only twice a day.
Factors to consider in the treatment of scouring calves:
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Isolation. Many causes of scour can be passed on to other calves through contact.
Therefore, the sooner an affected calf is moved to an isolation pen, the fewer the
number of calves are likely to need treating.
Maintain nutrition. Do not stop milk – it is essential for gut repair. If calves are not
sucking, give 1litre at least four times daily. Adding a gel such as Rehydion will aid
milk clotting in the stomach, and hence improve digestion.
Avoid dehydration. Between milk feeds, additional water with electrolyte should be
given, for example Effydral or Lectade: these feeds should total 3-6 litres daily. This
will avoid dehydration, and the high bicarbonate content will reverse acidosis,
hopefully keeping the calf on its feet.
Pain relief. Scouring calves are in pain, and will recover more quickly with the aid of
non-steroidal anti-inflammatory drugs such as Metacam. They should be used with
care if the animal is hypovolaemic.
Antibiotics. In some cases, a dose of antibiotic may prevent septicaemia and deal
with gut bacterial overload. This has to be weighed against the risk of resistance.
Fluoroquinolones should be avoided unless there is no alternative.
TLC. The benefits of warmth, and a draught-free dry bed, should not be
underestimated. The effective treatment of scoured calves is very labour intensive, a
point that needs to be emphasised to the client
Veterinary examination and treatment should be sought if calves are not responding to
treatment. If a calf is unable to lift its head, intravenous fluids are needed – this is worth
considering with a valuable calf.
Follow up
A farmer asking for scour treatment is an excellent point to start a farm investigation. A farm
visit should look at all aspects of calf management, from colostrum to bedding. For example
if there is insufficient feed for the calf, is it surprising that they will eat their own bedding
thereby increasing the risk of coccidiosis? We have to consider all aspects such as this if we
are to sell our advice in an ever more competitive market.
Miranda Josephson BVSc MRCVS
Calweton Veterinary Group