Rabies vaccinations should be given to horses:

Rabies vaccinations for horses are generally recommended to be administered annually. This is because rabies is a fatal viral disease that can affect all mammals, including horses, and the vaccination provides critical protection against this serious illness. Most veterinary guidelines and regulatory bodies suggest that horses should receive this vaccination once every year to ensure sufficient immunity, as the duration of the vaccine's effectiveness can vary and is most reliably maintained with annual boosters.

While some other vaccines may have longer intervals or may be effective for several years, rabies vaccination should be more frequent due to the high risk of exposure in certain environments and the severe consequences of contracting rabies. Keeping up with the annual schedule helps to safeguard not only the health of the horse but also public health, as rabies is transmissible to humans.