Scottish vets issue warning on incurable sheep disease
Published:  26 June, 2014

Vets are urging sheep farmers to be on their guard to the increasing threat from Maedi Visna (MV), a disease that is incurable to sheep.

Scotland’s Rural College’s (SRUC) vets fear the industry has adopted an “out of sight, out of mind attitude to the threat”.

Specialists from Veterinary Services, part of the College’s SAC Consulting Division, said there was evidence of infection increasing in the sheep population, with a high level discovered in some flocks. The college said that analysed samples showed that, in one flock, 11 of 12 ewes tested positive, and in another 41 of 48 were positive.

Ian Pritchard, health schemes manager, said: “It is true to say that these flocks suspected an issue and were prepared to deal with it. But how many flocks out there could have an issue, but have not, or are afraid to look for MV? Producers cannot afford to be complacent and underestimate the risks of the disease. It could have a severe effect on the productivity and economics of their sheep system.”

According to SRUC, the disease can lead to poor body condition, poorer fertility, increased mastitis, smaller and weaker lambs and increased mortality, with no cure for MV and no vaccine.  

Pritchard said that warning signs suggest the problem is growing: “Statistics from veterinary laboratories in England, Wales and Scotland show an increase in outbreaks. Several larger flocks have encountered MV to their cost. One example is a flock with 8% ewe mortality, a high cull rate due to mastitis and poor condition resulting in a high net replacement cost, and lambs often with poorer growth rates.”

He recommended that sheep farmers join the MV accreditation scheme, run by Premium Sheep and Goat Health Schemes, whose members test their sheep regularly and follow certain rules and conditions. “If you are already a member of the MV accreditation scheme, then you are at a very low risk providing you follow the stringent biosecurity regulations that are designed to protect your flock and the flocks of your customers,” he added.