Hypothermia is a particular risk to newborn lambs born outdoors or in exposed sheds. The normal rectal temperature of newborn lambs is between 39ºC and 40ºC. Lambs with a temperature between 37ºC and 39ºC are weak, but should be able to feed.

Lambs with a temperature less than 37ºC stand with an arched back, empty flanks and a lowered head. Their stance may give the impression they are suckling, however, these lambs are not able to suckle. If left unattended they will die. At post mortem examinations, such lambs will have empty stomachs and their fat reserves will be depleted. They need to be dried thoroughly, warmed up to 39ºC and fed.

Ideally, they should be warmed up with a fan-type heater rather than a heat lamp. The importance of newborn ruminants receiving enough colostrum (biestings) cannot be overemphasised. Acidosis as a result of difficult calvings and lambings can reduce the animal’s ability to absorb colostrum. This transfer of immunity is crucial for good health. Failure to achieve this predisposes the lamb to a variety of conditions, including septicaemia, scour, meningitis, peritonitis, liver abscesses, spinal abscesses and endocarditis.

Several of these conditions may be introduced into the body through the navel. In the early days, the navel should be treated like an open wound, in that it allows access of bacteria into the body. Bacteria building up in the environment is another predisposing factor to the occurrence of many of these navel related conditions occurring. A clean environment and maintenance of a clean, dry bed for newborn animals is crucial. While it is important to disinfect the navel, this in itself won’t overcome an unhygienic environment. The use of very concentrated iodine-based solutions may actually irritate the navel, thereby giving rise to infections. Therefore, the choice and concentration of navel disinfectant should be carefully considered. Rotavirus and cryptosporidium continue to be the main causes of scour in young ruminants, with E.coli K99 and coronavirus being the less common causes. There are vaccines available to boost the protection from colostrum for all of these pathogens, apart from cryptosporidium. Therefore, it is important to know what is causing scour so that the best preventative measure can be put in place. Lamb dysentery (bloody scour), caused by clostridium perfringens type B, can be a significant cause of sudden death in flocks, where clostridial vaccination is not administered to ewes during pregnancy. It usually affects lambs up to two weeks of age. Outbreaks occur in cold, wet springs, when ewes are confined to sheltered areas and conditions become dirty. Like all clostridial diseases, it tends to affect the strongest individuals in the group.

*Damien Barrett is a vet who works at the Sligo regional veterinary lab.