Dirofilariasis in a female dog in the municipality of Belo Horizonte, MG - Case report

Resumo

Canine dirofilariosis is a parasitic disease caused by Dirofilaria immitis. It has a worldwide distribution and is of significant importance in veterinary clinical practice due to its potential to cause cardiopulmonary and systemic abnormalities. This study aims to report an unusual case of canine dirofilariasis associated with osteoproliferative changes in a female dog treated at a veterinary clinic in the Pampulha region of Belo Horizonte, Minas Gerais. The female patient was referred to the clinic in July 2024 presenting with hindlimb lameness, respiratory abnormalities, and myoclonus, and was initially investigated for canine distemper. Diagnostic evaluation revealed severe regenerative anemia, persistent proteinuria, and elevated inflammatory markers. Radiographic examinations performed for the surgical planning of a cranial cruciate ligament rupture revealed extensive periosteal reactions in the femurs, ribs, and humeri, initially suggestive of osteomyelitis, hypertrophic osteopathy, or a polyostotic neoplastic process. Further investigation via abdominal ultrasound did not identify any primary neoplasms. The definitive diagnosis was established through echocardiography, which revealed adult Dirofilaria immitis worms in the right atrium. Following the initiation of specific treatment for dirofilariasis, progressive clinical improvement, normalization of hematological parameters, regression of bone abnormalities, and the absence of parasites on follow-up echocardiographic examinations were observed. It is concluded that dirofilariasis should be considered a differential diagnosis in dogs presenting with multifocal osteoproliferative lesions and nonspecific systemic manifestations—particularly in areas where the parasite is endemic—highlighting the importance of an integrated diagnostic approach for accurate diagnosis and therapeutic monitoring.