Vaccination protocols questioned

A report in the Veterinary Record (26/7/08) suggests that some farmers are still not providing adequate protection to ewes and lambs against the threat posed by clostridial diseases.

The report claims that outbreaks of cloistridial disease in May were common following inadequate or no vaccination, and states that 18 Scottish flocks were diagnosed with pulpy kidney.

On one Ross-shire farm, four apparently healthy three-week-old charollais lambs died suddenly after turnout. In this case, the ewes had not been vaccinated, although the lambs had received a single dose of a clostridial vaccine.

Intervet/Schering-Plough animal Health's veterinary adviser, Rosemary Booth, is keen to emphasize the need for correct vaccination protocols. "Failing to complete a course of the two doses required to deliver disease protection will leave ewes and lambs at risk from clostridial diseases and pasteurella," warns Ms Booth.

"Giving ewes an annual booster 4-6 weeks before lambing boosts their immunity and provides a level of protection to newborn lambs via the colostrum before they too can be vaccinated," Ms Booth advises. "Newborn lambs should receive one dose of a suitable vaccine from around three weeks of age, and another 4-6 weeks later – see fig 1. Failure to give this second dose will result in lambs with little or no immunity whatsoever, leaving them at risk."

At this time of year, many farms will be buying in replacement stock. Irrespective of their vaccination history, the safest approach is to assume all new arrivals have not been vaccinated against clostridial diseases and pasteurella. Two doses of a suitable vaccine 4-6 weeks apart as soon as they arrive on the farm will protect them against these diseases. A further single dose each year, 4-6 weeks prior to lambing, will then be all that is required to maintain this immunity.