By Gregg A. Hanzlicek, DVM, PAS, PhD
In 2017, the Kansas State Veterinary Diagnostic Laboratory and the Kansas State College of Veterinary Medicine initiated a state-wide Kansas cow-calf anaplasmosis prevalence study.
One hundred and sixty four licensed veterinarians collected blood samples from herds in their practice area. In total, 925 herds (9,250 animals) were sampled. Veterinarians, herds, and animals within each herd were randomly selected for this study. Diagnostic testing was completed on each blood sample to estimate the percentage of positive Anaplasmosis herds residing in each Kansas Agricultural District. This study did NOT determine what percentage of animals within each herd were positive.
The results were surprising for some producers and veterinarians in Western Kansas. The percentage of herds found anaplasmosis positive ranged from 18.0% in the NW district to 33.9% in the SW district. (Map below) Much greater prevalence numbers were found in Eastern Kansas where it is considered to be endemic. The central portion of the state was found to have intermediate prevalence levels, compared to Western and Eastern districts.
Herds using insecticide ear tags or the anaplasmosis vaccine were more likely to be positive. Interestingly, herds that burnt a greater portion of their pastures, as a practice management technique, each year were more likely to be anaplasmosis positive compared to those who did not practice pasture burning or burnt less than 20% of their total pasture acreage.
Producers are encouraged to work with their local veterinarian to design appropriate Anaplasmosis prevention and control programs.