POST mortem reports consistently show that the increase in sudden deaths in lambs in the autumn is down to pasteurellosis.
Many of these deaths could have been prevented by vaccination.
Veterinary surgeon, Andrea Turner of Langford farm animal practice, Langford Vets, Bristol says: "At this time of year we always see a rise in the number of lamb losses which can be attributed to clostridial disease and more commonly pasteurellosis."
Pasteurellosis is caused by two main types of bacteria - Mannheimia haemolytica is more likely to cause pneumonia in younger lambs and Bibersteinia trehalosi will cause systemic pasteurellosis in lambs four to 10 months of age.
"The bacteria are present in healthy sheep but stress causes the lamb's normal immune defences to be reduced and allows the bacteria to cause disease.
This can be triggered by a number of factors which are especially prevalent in the autumn including change of diet, handling, bad weather, transport or other disease.
"Lambs will go downhill very quickly or often die having had no clinical signs of illness. If an outbreak develops there is very little that can be done at that stage, so it really is a case of prevention is better than cure and vaccination is a cost effective option.
"Even if lambs have been vaccinated at younger age their immunity may be starting to wane particularly if under stress and if you are buying in store lambs of unknown provenance it is certainly worth vaccinating them.
"If they are lambs which will ultimately be slaughtered, a four-in-one vaccine should be sufficient, but for ewe lambs intended to be kept for breeding a seven-in-one vaccine is a better option.
"Also beware of buying in a parasite burden which impact on a lamb's immune system. Talk to your vet and have a vaccination and parasite treatment plan in place to prevent avoidable losses."
FARM FACTS
- Clostridial diseases and pasteurellosis are one of the most common causes of sudden death in lambs, but can be mostly prevented by vaccination.
- Providing ewes are on a vaccination programme and have received a booster four to six weeks before lambing they should pass protective antibodies to their lambs via colostrum. However, this will start to wane after several weeks.
- Lambs can be vaccinated from three weeks old and will require a second dose between four and six weeks later.
- Stress due to increased handling, change of diet and weather can trigger pasteurellosis in store lambs in autumn so an additional course of vaccination is recommended even if they have previously been vaccinated.
