Intracardiac rhabdomyosarcoma in a dog.

Intracardiac rhabdomyosarcoma was diagnosed in a 14-month-old Golden Retriever referred for evaluation of syncope. The dog was weak, with irregular heart rate, pulse deficit, heart murmur, and hepatomegaly. Thoracic radiography revealed generalized cardiomegaly, and electrocardiography revealed sinus rhythm with multiform ventricular premature complexes and intermittent ventricular tachycardia. Two-dimensional echocardiography revealed extensive soft-tissue density masses in both ventricles. An intracardiac neoplasm seen at postmortem examination was identified histologically as rhabdomyosarcoma, an uncommon intracardiac tumor in dogs.

Acquired myasthenia gravis and cholangiocellular carcinoma in a dog.

Acquired myasthenia gravis and cholangiocellular carcinoma were diagnosed in a 7-year-old English Setter referred because of forelimb lameness, exercise-induced weakness, and fever. Three months earlier, the dog had had a pleuropulmonary infection caused by a Fusobacterium sp. The concurrent development of myasthenia gravis and cholangiocellular carcinoma in this dog may be explained by a paraneoplastic syndrome, although it is unproven. The cholangiocellular carcinoma may have possessed an acetylcholine receptor-like antigen on the tumor surface, which induced autoantibodies to cross-react with acetylcholine receptors at the neuromuscular junction.

Chronic obstructive pulmonary disease in a dog.

Chronic obstructive pulmonary disease was diagnosed in a 3-year-old Basset Hound that was referred to the hospital because of respiratory distress. Results of radiography, bronchoscopy, and pulmonary function tests indicated lung hyperinflation, airflow restriction, and loss of elastic recoil of the lungs. Because of the poor response to treatment, the dog was euthanatized. Postmortem findings revealed emphysema, bronchiectasis, and bronchitis, which comprise chronic obstructive pulmonary disease.