By Kindra Gordon

Clostridial vaccines, also commonly referred to as “7-way” or “8-way” vaccines, are primarily administered to calves to prevent blackleg, malignant edema and redwater. All of these diseases can cause rapid death of affected cattle.
During a Cattlemen’s College session this past winter, in Phoenix, Ariz. Victor Cortese offered tips to ensure efficacy of clostridial vaccinations in cattle. Cortese is a veterinarian and director of cattle and equine immunology for Zoetis.
He suggested vaccinating a pregnant cow is ideal, so the newborn calf can gain early protection via colostrum. Ideally, Cortese advises administering a clostridial vaccine 4 to 11 weeks prior to calving to allow the cow to respond to the vaccine and the protection to be passed to her colostrum. “Six to 9 weeks prior to calving is the optimum time, and that coincides with administration of other scours vaccines,” he pointed out.
Because clostridial spores are always present in the soil, Cortese also suggests minimizing overgrazing can help prevent cattle from picking up the spores into their system. As well, because the clostridial organisms are commonly picked up in grazing, the ideal time to vaccinate or booster calves and cows is typically in late spring or early summer.
Cortese notes that Clostridial vaccinations almost always cause a small knot or lesion on the animal’s neck. To help minimize this, vaccinations should be given subcutaneously. Newer, less reactive vaccines are available, and might be preferred for show cattle, he shares.
Additionally, Cortese says proper handling of the vaccine can help decrease injection site lesions and maximize protection. This includes:
• Storing the vaccine correctly at 35-45°F. “Don’t store the vaccine in the door of the refrigerator because the temperature fluctuates every time you open that door,” he says.
• Get dosage sizes you can use quickly. “Once you break the seal on a clostridial vaccine, they degrade 14 to 21 days later. So use it up as quickly as possible. Don’t store a partial bottle beyond 30 days,” says Cortese.
• Don’t use a clostridial vaccine if it has been frozen. “Freezing can increase the toxins in those vaccines,” he concludes.