Theileria annae (syn. Babesia microti-like) infection in dogs in NW Spain detected using direct and indirect diagnostic techniques: Clinical report of 75 cases

Background: in north-western spain,piroplamosis caused by theileria annae is now recognized as a serious problem because veterinarians,despite being aware of the clinical signs of piroplasmosis,lack the necessary information on its epidemiology or specific diagnostic tools for its management. this,along with the fact that t. annae infection is also refractory to current piroplamosis treatments,prompted this study designed to assess the clinical presentation and diagnosis of this largely unknown parasitic disease in dogs. methods: one hundred and twenty dogs in nw spain suspected clinically of having piroplasmosis were examined and piroplasm species detected by light microscopy (lm) observation of giemsa-stained blood smears,immunofluorescent antibody test (ifat),and pcr plus sequencing. results: seventy five of the sick dogs were confirmed to be infected with t. annae by pcr (designated true infection cases). intraerythrocytic ring-shaped bodies morphologically compatible with small piroplasms were observed by lm in 59 (57 true infections) of the 120 blood samples. anti-babesia antibodies were detected by ifat in 59 of the 120 sera (55 of which were true infections). using pcr as the reference method,moderate agreement was observed between positive lm vs pcr and ifat vs pcr results (kappa values: 0.6680 and 0.6017,respectively). microscopy examination and ifat were moderately sensitive in detecting the pathogen (76% and 73.3%,respectively). in the 75 cases of true infection