Comparisons of serotests with calf inoculations for detection of carriers in anaplasmosis- vaccinated cattle.

Fifteen months after discontinuing vaccination for anaplasmosis in a herd of 131 cattle, 126 of the animals were reactive to the complement-fixation or card-agglutination tests. Inoculation of splenectomized calves proved that 9 animals were carriers and 117 animals were free of anaplasmosis. Anaplasmosis vaccination induced titers detectable by the standard serotests that persisted for at least 15 months.