Diagnosis and surgical treatment of associated papillary lung adenocarcinoma to canine distemper: case report

Lung neoplasms in dogs have a multifactorial etiology, and animals aged 10 or older are the most affected, with no sexual or racial predisposition. Adenocarcinoma is the most common type of cancer and represent around 80% of the cases. The aim of this study was to describe a case of an 11-year-old dog of no defined breed (SRD) with papillary lung adenocarcinoma and canine distemper virus. Clinical examination revealed a body condition score (BCS: 5.0), normocardial, tachypneic, normothermic, mild dehydration (5 - 6%), hyporexia, hypocolored mucous membranes, normodipsia, normuria and normoquesia. Hematological tests (blood count, biochemistry) were carried out, initially showing leukocytosis and regenerative anemia. Imaging tests of the chest (x-ray) and computed tomography (CT) showed a nodule, with approximately 7cm in circumference in the ventral portion of the right caudal lung lobe. Treatment was by thoracotomy to excise the nodule. The excised material was sent for histopathological and immunohistochemical diagnosis, which confirmed the diagnosis of lung adenocarcinoma. Infection with the distemper virus was confirmed by the identification of the Lentz corpuscle, which was found in the blood sample during the differential leukocyte count, when the animal was returned for re-evaluation. The animal did not respond to treatment and died 48 hours after the diagnosis of distemper, in response to cardiorespiratory arrest, 12 days after the removal of the nodule. Infection with the distemper virus led to an unfavorable prognosis and made post-surgical treatment impossible, culminating in the animal's death.