What is the recommended vaccination schedule for sheep?

The recommended vaccination schedule for sheep primarily focuses on preventing clostridial diseases, which can be life-threatening and are caused by bacteria present in the environment. Administering vaccinations at weaning is critical because young sheep are particularly vulnerable to these pathogens. Once the initial vaccination is completed at weaning, annual revaccination is essential to maintain immunity and protect the animals as they grow and face various environmental challenges. This approach helps ensure that the flock remains healthy and minimizes the risk of outbreaks of these serious diseases.

In contrast, the other options either do not provide an effective vaccination strategy or omit crucial protection for the sheep. For example, vaccinating only before shearing and annually does not account for the specific timing needed to protect young sheep immediately before they are stressed by weaning. A biannual vaccination schedule is often unnecessary and could lead to unnecessary costs and labor without significant benefits in terms of immunity. Additionally, vaccinating only once in a lifetime would leave sheep unprotected for the majority of their lives, significantly increasing their susceptibility to communicable diseases.