Ultrasonographic and elastographic findings of the liver of dogs exposed to cigarette smoke.

Smoking is identified as one of the main causes of non-transmissible diseases, damaging organs such as the lungs, liver, kidneys, and heart. Owing to their proximity to smokers, dogs are passively exposed to substances present in cigarette smoke. We aimed to describe the ultrasonographic and elastographic findings of the livers of dogs exposed to cigarette smoke. The study involved 13 dogs chronically exposed to cigarette smoke and 10 with no history of exposure to cigarette smoke or progressive liver changes in the preceding 6 months. The animals were subjected to laboratory testing, B-mode ultrasound, and Shear Wave elastography. Statistical analyses used a binomial model for categorical variables and a negative binomial or Poisson model for numerical variables, considering a p-value <0.05. Dogs exposed to tobacco smoke showed reduced liver stiffness. This result may be associated with a congestive process or fatty liver disease. Hepatic congestion may be associated with pulmonary hypertension caused by the inhalation of cigarette smoke. Exposure to tobacco smoke leads to the progression of hepatic fatty infiltration. However, histopathology and a detailed cardiopulmonary investigation are required to confirm these hypotheses. Dogs exposed to cigarette smoke tended to exhibit hepatomegaly and altered liver echotexture. Dogs over 5 years of age tended to show altered liver echogenicity. The B-mode ultrasonography and elastography findings suggest that passive exposure to cigarette smoke can adversely impact animal health. The findings may provide a basis for future investigations among relatively large and homogeneous populations.