Proliferative parathyroid lesions in captive-bred American bullfrogs (Lithobates catesbeianus) with metabolic bone disease.

Parathyroid gland lesions in anurans are infrequently reported and most often occur secondary to experimental interventions. Husbandry-related parathyroid changes have not been documented in this order of Amphibia. Three American bullfrogs (Lithobates catesbeianus) living in a captive colony were euthanized due to clinical concern for metabolic bone disease secondary to lack of consistent dietary supplementation with vitamin D3. Necropsy revealed cystic dilation and variable proliferation of unidentified structures within the cranial coelom corresponding to the anatomical location of anuran parathyroid glands. Histologically, the structures consisted of sheets and whorls of elongated cells. Immunohistochemistry for pan-cytokeratin revealed strong cytoplasmic staining and Grimelius staining identified neuroendocrine granules in the elongated cells of these structures, supportive of a parathyroid origin.

Total protein concentration as a predictor of neoplastic peritoneal and pleural effusions of dogs.

BACKGROUND: The diagnosis of neoplastic cavitary effusions requires the identification of neoplastic cells in effusions, yet the cytologic appearance of neoplastic effusions can be highly variable due to the varied mechanisms of formation. Additional parameters might aid in the interpretation of equivocal cytologic results. OBJECTIVES: Our goal was to evaluate whether total protein concentrations can be used to support the diagnosis of neoplasia in the peritoneal and pleural effusions of dogs with lower cellularities (≤5000 nucleated cells/µL). METHODS: Pleural and peritoneal fluid analyses from dogs presented to the University of Illinois Veterinary Teaching Hospital between 2014 and 2019 were evaluated retrospectively. Effusions were categorized as neoplastic or non-neoplastic based on histology or cytology. Non-neoplastic effusions were subcategorized according to mechanism: decreased oncotic pressure, increased hydrostatic pressure, increased vascular permeability, leakage of urine, and leakage of lymph. The TP and blood albumin to fluid TP ratio (Albblood :TPfluid ) were compared among groups. RESULTS: Twenty-seven neoplastic and 65 non-neoplastic cases were evaluated. TP was higher in the neoplastic group (P = .001) than in the non-neoplastic group. Neoplastic effusions had a lower Albblood :TPfluid than non-neoplastic (P = .001), and effusions with Albblood :TPfluid of ≤0.6 were 5.6 times more likely to be neoplastic (95% CI 1.69-17.36; P = .003). CONCLUSIONS: Fluid TP concentrations were significantly greater in neoplastic than non-neoplastic effusions; however, given the considerable overlap between groups, the diagnostic utility of this difference is low. A neoplastic etiology might be more likely in cases with an Albblood :TPfluid ≤0.6.