Paraneoplastic syndromes

Hypertrophic Osteopathy Associated with Mycotic Pneumonia in a Roe Deer ( Capreolus capreolus)

Aspergillus fumigatus is one of the most common Aspergillus species causing disease in individual animals but it rarely affects deer species. We report a case of A. fumigatus infection causing mycotic pneumonia and hypertrophic osteopathy in a roe deer ( Capreolus capreolus).

Hypertrophic Osteopathy Associated with Mycotic Pneumonia in Two Juvenile Elk (Cervus Elaphus)

Two yearling bull elk ( Cervus elaphus) from the same farm developed anorexia, weight loss, and lameness. On physical examination, both elk were thin and showed diffuse swelling of all lower limbs. Radiographs of the lower limbs showed periosteal thickening of the distal extremities, consistent with hypertrophic osteopathy. Thoracic radiographs indicated the presence of pulmonary nodules. Cytologic evaluations of tracheal washes on both elk were consistent with inflammation. Acid-fast stains on both samples were negative. Because of the poor prognosis, both elk were euthanized. At necropsy, the carpal, metacarpal, tarsal, and metatarsal bones, as well as the radius, ulna, and tibia had thickening of cortical bone. There were multiple encapsulated nodules throughout the lungs, lymph nodes, and kidney, and smaller nodules in the myocardium. On microscopic examination, these nodules contained myriads of hyphae, and immunohistochemistry for Aspergillus sp. was strongly positive. Aspergillus fumigatus was isolated from affected tissue in 1 elk. Necropsy findings in both elk were consistent with disseminated fungal granulomas and periosteal hyperostosis. This case presents the first description of hypertrophic osteopathy in elk. The source of infection was undetermined, but inhalation of spores from contaminated feed or bedding was suspected.

Secondary Erythrocytosis Associated with Schwannoma in a Dog

An 11-year-old, spayed female mixed-breed dog showed clinical signs of right forelimb lameness and pain by palpation around the neck. Radiography and computed tomography (CT) revealed an extradural mass at the 6th and 7th cervical vertebrae, which compressed the spinal cord. The mass was surgically removed and histopathologically diagnosed as schwannoma. The dog recovered her normal gait after hemilaminectomy and removal of the mass. Ten months after the surgery, the tumor recurred with absolute erythrocytosis and was surgically removed again. This removal temporarily resolved the erythrocytosis with a decrease in plasma erythropoietin (EPO) concentration. EPO protein was detected immunohistochemically in the tumor cells. Erythrocytosis in this dog may be caused by ectopic EPO produced in the schwannoma tissues.