Variable weather patterns and waning maternal immunity could leave lambs exposed to clostridial diseases this spring.
Experts are urging farmers to review vaccination protocols to protect youngstock – especially as immunity passed on through antibodies in their mother’s colostrum starts to fade after just a few weeks.
“Once this protection declines, lambs can be hit hard by diseases that progress rapidly and are often fatal,” says MSD Animal Health veterinary adviser Kat Baxter-Smith.
Unnecessary losses from clostridial disease are particularly common during the spring. Data from Farm Post Mortems showing a peak in pulpy kidney cases among lambs aged 2-8 weeks, with almost all affected animals unprotected by vaccination.
“Stressors that farmers cannot control, such as sudden weather changes, dietary shifts or parasite burdens, can trigger outbreaks.”
“This means farmers with lambs at risk would be wise to speak with their vet and consider vaccination for clostridial disease, even in lambs not intended for replacements.”
Common clostridial diseases affecting sheep include lamb dysentery, tetanus, pulpy kidney, black disease, blackleg, struck and braxy. But almost 20% of sheep farmers do not carry out any routine vaccinations.
Critical time
“Vaccinating lambs at the right time is critical,” stresses Dr Baxter-Smith.“Farmers using Heptavac P Plus in their ewes should follow up with a primary course for replacement ewe lambs from three weeks of age.
Lambs intended for finishing should also be considered for vaccination with Ovivac P Plus, even if they are destined for slaughter this year. This protects against four key clostridial pathogens and helps control pasteurellosis.
Clostridial infections progress quickly and intensive antibiotic treatment is rarely effective.
Control is best achieved through vaccination – with Heptavac P Plus for breeding stock and Ovivac P Plus for growing lambs.
“With unpredictable stress triggers, farmers must be proactive rather than reactive,” adds Dr Baxter-Smith. “A timely vaccination programme is the best safeguard against costly and preventable losses.”