Almost a quarter of ewes tested for Maedi Visna (MV) by SAC Consulting Veterinary Services are carrying the disease. This could mean that large numbers of livestock are at threat of ill-thrift, failing to grow at a healthy rate, this winter.
The tests were carried out on flocks throughout England, although vets are warning that the disease is also present in Scotland and Wales. Most flocks tested were cross-breeds and mules and the owners reported ewes being thin, breathless and sometimes lame. The ewe mortality rates were increased and lambing percentages and growth rates reduced.
Maedi Visna is a chronic viral disease which was introduced into the UK through imported sheep. It has since spread, especially in commercial flocks. The condition is highly contagious, difficult to diagnose and is fatal.
As flock owners and shepherds are preparing their flocks for mating in the weeks ahead, SAC Consulting is urging them to investigate any cases of ill-thrift in ewes with their veterinary surgeon.
“Ewes should be in good condition at tupping this year given the good weather we have seen this autumn” says Brian Hosie, Head of SAC Consulting Veterinary Services. “This makes it all the more important farmers and crofters quickly work out why some ewes may not be performing”.
Farmers worried about their flock should condition score their ewes and manage them accordingly; this will allow them to identify ewes which are not improving. There are many diseases other than MV that can cause ill-thrift in sheep flocks. These include liver fluke, worms, trace element deficiency, Johne’s Disease and OPA/Jaagsiekte.
Veterinary surgeons can find out what is causing ill thrift through collecting samples of faeces or blood for analysis or through arranging for some animals to be examined post mortem. Often more than one condition is responsible, however the results will allow flock owners and shepherds to set up a suitable treatment and control programme for the flock.
