Bovine babesiosis in dual purpose calves in the state of Yucatan, Mexico.

Thirty-eight dual purpose calves in the 3 agricultural zones of the state of Yucatan, Mexico were monitored for antibodies to Babesia bovis and B. bigemina from close to birth up to 12 months of age. The results showed that infection with both parasites is widespread throughout the 3 zones. Many of the animals had produced antibody to both parasites by 6 months of age indicating high transmission rates resulting in enzootic stability for both parasites. Any changes to agricultural practices in the state that could affect disease stability through either reduction in numbers of tick vectors or the introduction of susceptible adults will have to be accompanied with measures such as vaccination to limit losses due to clinical babesiosis.