During the week of the Easter Rising over 100 years ago, there were adverts in the national press marketing novel remedies for white scour in calves. They were being touted as cure-alls, but, alas, those remedies are no more, yet scour control remains as challenging today as it was then.

It is worth noting that at that time, the discovery of antibiotics was still decades away and yet today, despite the many antibiotics available, most scour treatment and control is achieved without a major reliance on antibiotics.

The lining of the calf’s intestine is not actually a smooth surface, but more like a thick brush of papillae, akin to a tightly bound deep pile carpet. These papillae greatly increase the surface area of the gut lining, thereby ensuring that fluid and nutrient absorption/retention is maximised.

The common pathogens (bugs) affecting young calves (rotavirus, crypto, etc) can affect this absorptive process and, in many cases, damage and stunt the papillae, thereby greatly reducing the absorptive function of the gut, resulting in scour.

Whole milk contains factors which can help repair gut papillae, which is why it is so important to feed some milk to scouring calves as well as fluids.

An important point to remember is to feed milk and electrolytes separately, as diluting whole milk with water or electrolytes may reduce the digestibility of the milk, which is particularly critical in the scouring calf. There are three important stages.

Dehydration

This is very noticeable when it presents. Apart from the obvious scour symptoms, such calves will present with a sunken eye and a skin tent will be easily observed if the skin is pulled. Mild dehydration may be reversed using oral rehydration therapy and electrolytes, but more severe dehydration would need to be corrected by intravenous fluid therapy.

Acidosis

This can be more subtle and, quiet often, affected calves may present with a normal-looking eye with no evidence of dehydration. Some acidotic calves may present with shallow breathing with or without a slight abdominal fullness, which may be as a result of excess poorly digested milk. Intravenous fluids spiked with an alkalising agent can reverse the acidosis in most cases.

Cachexia

Cachexia is the result of muscle wastage and is found where the scour becomes more persistent, resulting in prolonged malabsorption. This is best observed where the outline of the bones in the hind limb becomes obvious in calves with persistent diarrhoea. Cachexic calves are more difficult to manage and reversing the situation here will take time. If there are many such calves, it may be an indicator that the management of calf scour needs to be reviewed.