PNEUMONIA CONTINUES to be a significant cause of death in sheep over 12 months of age.

Indeed, post mortem data show that pneumonia is the single biggest reason for these animal losses.

Disease outbreaks are also being seen in young lambs (up to two weeks of age) and in 6-10 month animals, but the reality is pneumonia affects sheep of all ages.

“With ewe and lamb values rising recently, Scottish sheep producers simply can’t afford to ignore the threat of pneumonia in the run up to lambing,” said livestock veterinary adviser, Rosemary Booth, from Intervet/Schering-Plough Animal Health.

“The disease can have a variety of causes, but the majority of outbreaks are caused by pasteurellosis. Pasteurella are a group of bacteria, with mannheimia haemolytica and bibersteinia trehalosi being the most important types to cause disease in sheep.

“On average, eight out of every 10 sheep harbours these bacteria, rising to 95% in some flocks. As with clostridia, under normal circumstances the pasteurella bacteria do not cause disease unless a trigger factor such as weaning, bad weather or a change of food causes them to multiply rapidly, spread round the body and release toxins. The end result is usually death.”

Antibiotics are often used when an outbreak occurs, but as the disease cause is usually very short they rarely save any seriously affected lambs. “The unpredictability and rapid onset of an outbreak of pneumonia, the uncertainty of treatment success and the sheer cost of lost animals – means a comprehensive vaccination programme can be easily justified,” Ms Booth added.

“For example, ewes that are vaccinated with Heptavac-P Plus in the run up to lambing can also confer immunity onto their lambs. As well as covering the ewe, the vaccine also increases the concentration of antibodies in the ewe’s colostrum, which pass to the new born lamb when it suckles.”