Chronic heart failure due to severe endocardiosis in a Gambian giant pouched rat (Cricetomys gambianus)

SQUAMOUS CELL CARCINOMAS WITH PULMONARY METASTASIS AND ENDOCARDIOSIS IN THE SIBERIAN CHIPMUNK ( EUTAMIAS SIBIRICUS): TWO NECROPSY CASES

Reports of neoplastic diseases in the Siberian chipmunk ( Eutamias sibiricus) are limited. The authors describe herein two necropsy cases of Siberian chipmunks with squamous cell carcinoma; both of which showed self-biting behaviors on presentation to the clinician. In both cases, the neoplasms comprised trabeculae and islands of polyhedral cells, supported by moderate amounts of fibrous stroma. Anisocytosis and anisokaryosis were moderate to prominent. Neoplastic cells were occasionally keratinized, with a keratin pearl formation. In one case, valvular endocardiosis of the left and right atrioventricular valves with secondary pulmonary and hepatic lesions was incidentally diagnosed. This report provides the first documentation of squamous cell carcinoma and endocardiosis in the Siberian chipmunk.

Mandibular osteosarcoma in a nutria (Myocastor coypus)

A four-year-old neutered male nutria (Myocastor coypus) was presented for a one-day history of lethargy and anorexia. A right-sided facial swelling and loose right mandibular fourth molar that exuded caseous exudate from the root were noted; however, the animal continued to decline despite removal of the affected tooth and antibiotic and anti-inflammatory therapy. Radiographs showed a lytic proliferative bony lesion on the right mandible that appeared to expand in size over the course of a week. Due to its declining clinical condition and poor response to therapy, the animal was euthanized. Necropsy revealed an invasive bony neoplasm of the right mandible, histologically consistent with an osteosarcoma, that was invading the mandible and dental arcade, likely contributing to tooth root infection and osteomyelitis. Endocardiosis of the tricuspid valve was incidentally found as well with early cardiac remodeling of the right ventricle. This is the first report of an osteosarcoma and endocardiosis in a nutria.