Thoracic and abdominal mesothelioma in a dog: a cytologist’s view

Mesothelioma is an uncommon tumour in dogs, whose diagnosis can be a challenge to the veterinary cytologist. This paper aims to report a case of mesothelioma in a dog, obtained from the cytological analysis of pleural and abdominal fluid, which allowed an in vivo diagnosis. A 4.10-year-old-boxer dog was presented for clinical care with abdominal distension, difficulty in breathing and loss of appetite. Laboratorial and imaging tests were performed, and the cytology of abdominal and pleural effusions suggested the presence of mesothelioma. The cytology was ratified later by a histopathology of the lungs, ovaries, liver, spleen, peritoneum and omentum.