Heat pretreatment of canine samples to evaluate efficacy of imidacloprid？+？moxidectin and doxycycline in heartworm treatment

Considering the recent information on the increase of Dirofilaria immitis antigen detection by rapid assays in canine blood samples after heat treatment, the proposal that immune complexes block D. immitis antigen detection and that macrocyclic lactone？+？doxycycline (alternative protocol) might lead to increased production of those immune complexes, resulting in the erroneous diagnosis of adult worm elimination, and that there is no recommended adulticide marketed in Brazil, a study was performed to evaluate the interference of moxidectin？+？doxycycline (moxi-doxy) on diagnostic procedures when heartworm positive dogs are treated with this alternative protocol. Twenty-two naturally infected pet dogs were treated monthly with topical 10% imidacloprid？+？2.5% moxidectin and with oral doxycycline (10 mg/kg BID/30 days) (moxi-doxy). All the dogs had their microfilaremia level determined prior to the first day of treatment, and were tested every 6 months for microfilariae (Mf) detection prior to heating, and for antigen detection prior to and after heating, the sample