Prevalence of antibabesia antibodies in racehorses in Tuscany.

Babesia equi and Babesia caballi, worldwide diffused intraerythrocitic protozoa, are responsible for equine piroplasmosis. Their distribution depends on biological vectors, represented by 13 species of Ixodides. Indirect immunoflurescence test (IFAT) seems to be quitespecific and sensitive test. In the present work, the prevalences of infection caused by B. caballi and B. equi are reported. Serum specimens of of 440 thoroughbred and standardbred horses have been examinated by IFAT, for anti B. caballi and anti B. equi antibodies. All samples were collected during the period January 1997-July 1999. One hundred seventy two horses showed signs referable to Babesia and/or low racing performances. The other animals were checked within periodical control to prevent equine piroplasmosis. One hundred one specimens scored positive to IFAT: 84 (19%) for B. equi and 17 (4%) for B. caballi. Only one subject resulted positive both for B. equi and B. caballi (title 1/160 for B. equi and 1/1280 for B. caballi). All positive horses showed clinical signs (fever, icterus, anaemia) or worsening of racing performances. No significative difference on the basis of geographical distribution of horses, with regard to the positivity for B. equi, was observed. Sixteen out of the 17 animals positive to B. caballi lived together in the same district.