Clinical and echocardiographic findings in dogs with heartworm caval syndrome.

Abstract

Dirofilaria immitis is a nematode parasite that causes proliferative endoarteritis in infective dogs. The presence of the parasite in contact with the intima of blood vessels causes pulmonary hypertension which, if left untreated, can lead to right congestive heart failure. The pathology is commonly characterized by exercise intolerance, lethargy, and severe cardiorespiratory signs. Caval syndrome is a specific complication of the disease in which the parasite migrates from the pulmonary artery to the right heart and even to the cava veins. The purpose of this study is to determine clinical signs and echocardiographic findings in dogs affected by caval syndrome. A total of 51 animals were divided into three equal groups; healthy animals, animals affected by D. immitis and animals with caval syndrome, in order to determine the relevance of some clinical parameters for the identification and management of the disease. The investigation was based on the main clinical signs and on 11 different echocardiographic measurements performed ((RPADi, RVOT-FS, RVEDAi, RAAi, TRPG, TAPSE, AT:ET, PT:Ao, PV:PA, PRPG and Global-TDI). The results showed significant differences in the animals suffering from caval syndrome for the following parameters: respiratory symptoms, right congestive heart failure, breaths per minute, NT-ProBNP, hemoglobinuria and pulmonary hypertension, and also for all echocardiographic measurements, determining the importance of these measures for the diagnosis of pulmonary hypertension and other cardiovascular alterations in the caval syndrome, these being essential for its correct diagnosis and management.