Cystic renal disease in the domestic ferret.

Cystic renal diseases in domestic ferrets are a common anecdotal finding but have received scant systematic assessment. We performed a 17-y, case-control retrospective analysis of the medical records of 97 ferrets housed at our institution between 1987 and 2004, to determine the prevalence and morphotypes of cystic renal diseases in this species. Histologic sections stained with hematoxylin and eosin, Masson trichrome, or periodic acid-Schiff were evaluated by a comparative pathologist, and statistical analysis of hematologic and serum chemistry values was correlated with morphologic diagnosis. Of the 97 available records, 43 were eliminated due to lack of accompanying tissues. Of the 54 remaining cases, 37 (69% prevalence) had documented renal cysts, and 14 of the 54 ferrets (26%) had primary polycystic disease consisting of either polycystic kidney disease affecting renal tubules or, more commonly, glomerulocystic kidney disease. Secondary polycystic lesions were identified in 11 ferrets (20%), and 12 ferrets (22%) exhibited focal or isolated tubular cysts only as an incidental necropsy finding. Ferrets with secondary renal cysts associated with other developmental anomalies, mesangial glomerulopathy, or end-stage kidney disease had hyperphosphatemia and elevated BUN in comparison with those with primary cystic disease and elevated BUN compared with those without renal lesions. Although reflecting institutional bias, these results implicate primary and secondary cystic renal diseases as highly prevalent and underreported in the domestic ferret. In addition to the clinical implications for ferrets as research subjects and pets, these findings suggest a potential value for ferrets as a model of human cystic renal diseases.

Acute paraplegia in a young adult long-evans rat resulting from T-cell lymphoma.

We describe an unusual case of acute paraplegia in a young adult (7.5-month-old) Long-Evans rat that resulted from a spontaneous T-cell lymphoma. At presentation, a neurologic exam revealed normal pelvic limb flexor reflexes, the absence of an anal reflex, and deep pain recognition. Radiographs did not identify any obvious spinal abnormality or osseous trauma, although the liver and spleen were prominent. Hematologic analysis disclosed leukocytosis with atypical lymphocytes. At necropsy, red, friable to gelatinous masses were found associated with the ventral aspect of the vertebral column at the levels of the thoracic and lumbar vertebrae. Impression smears of the mass revealed a monocytic cell population with cells averaging 7 to 10 microm in diameter and having scant cytoplasm and pleomorphic nuclei, characteristics consistent with a lymphoid neoplasm. Histologically, the neoplasm was unencapsulated, poorly demarcated and highly infiltrative, invading and effacing the bone marrow and epidural space of the vertebral column. Neoplastic cells also were identified in the femoral bone marrow, spleen, liver, iliac and sacral lymph nodes, and lung. Immunophenotyping showed the neoplasm to be of T-cell origin. Although the lymphoma did not invade the meninges of the spinal cord, its impingement on the central and peripheral nervous systems resulted in foci of Wallerian degeneration that contributed to the paraplegia. This case report highlights the importance of having lymphoma and leukemia among the differential diagnoses in cases of acute paralysis in rodents.