Abstract
Pulmonary hypertension (PH) in dogs is a syndrome that could be primary or secondary due to pulmonary disease, pulmonary thromboembolism, heartworm disease, heart failure. Due to the inability of right heart catheterization in veterinary patients, there is a lack of differential criteria between PH forms. In some acute cases, it is impossible to provide a full EchoCG or catheterization study. In this situation, circulating markers could be useful to discover the possible mechanism of pulmonary hypertension form and provide specific therapy.
Following all previous data in human and veterinary studies, we supposed that plasm concentration of serotonin, endothelin-1 and VEGF-D would show a predominance of affected part of pulmonary circulation.
We studied 59 small-breed dogs of different sexes and ages. Groups were formed according to a primary pathology: healthy dogs (HD, n=8); dogs with MMVD and postcapillary PH (PostPH, n=23); dogs with MMVD and precapillary PH (PrePH, n=28). Animals in the study were diagnosed with the primary disease by standard echocardiographic methods and algorithms. Blood samples were collected at the presentation and frozen in a -80oC fridge. For biochemistry analysis we used species-specific ELISA kits, provided by Cloud-Clone Corp. (USA) The tests were provided by the means of Almazov National Medical Research Center, IEM laboratory.

Key words: Pulmonary hypertension, dog, biomarkers, endothelin, VEGF-D, Serotonin