Heartworm in a southern tiger cat (Leopardus guttulus) in Santa Catarina, Brazil

Abstract

Heartworm disease, caused by Dirofilaria immitis, is a vector-borne illness primarily affecting dogs but also documented in domestic and wild felines. In Brazil, a previous case was reported in a southern tiger cat (Leopardus guttulus) in São Paulo. This report describes the first documented case of heartworm disease in a Leopardus guttulus in Santa Catarina, Brazil. An adult female southern tiger cat was found on a city road in Joinville and presented with hypothermia, apathy, respiratory distress, and weakness. Despite supportive treatment, the animal did not recover and ultimately succumbed to its injuries. Necropsy revealed hemoperitoneum and hypovolemic shock due to trauma, with bite-associated wounds. Additionally, seven adult nematodes identified as D. immitis were found in the right ventricle, pulmonary artery, and femoral artery. Histopathological examination confirmed intravascular microfilariae, pulmonary vascular hypertrophy, hepatic congestion, and cardiac fibrosis, findings consistent with heartworm disease and congestive heart failure. This case underscores the need for further studies on heartworm disease in wild felines and potential zoonotic risk in endemic regions.