ABSTRACT
The canine immune response to Dirofilaria immitis is one of the most intriguing aspects of canine dirofilariasis. Dogs which are otherwise immunologically competent will support live adult worms and microfilariae. Humoral immune responses to experimental D. immitis infections in dogs have been studied by various investigators. The most recent study concerned with lymphocyte function in dogs with experimental infections demonstrated that B cells from Peripheral blood lymphocytes (PBL) of microfilaremic dogs were impaired in their ability to respond to a T-dependent antigen. The principal reason for immunodiagnosis of D. immitis infection is the diagnosis of occult dirofilariasis. The ectopic infections may be of significance in immunodiagnosis of dirofilariasis. These infections result from aberrant migration of developing larvae and, accordingly, adult worms may be observed in a variety of locations outside the cardiopulmonary system. In addition to the diagnosis of occult dirofilariasis, in general, there are other specific diagnostic questions which could potentially be answered with immunologic assays.
