Mixed germ cell-sex cord-stromal tumor with a concurrent interstitial cell tumor in a ferret

A 5-year-old male ferret presented with an enlarged canalicular testis in the left inguinal region. Microscopically, the enlarged testis consisted of a diffuse intimately admixed proliferation of c-kit-positive germ cell-like and Wilms tumor-1 protein-positive Sertoli cell-like components, but no Call-Exner body was detected. In addition, the compact proliferation of steroidogenic acute regulatory protein-intense positive interstitial cells was identified in a separate peripheral area of the mass. Based on histopathological and immunohistochemical findings, the tumor was diagnosed as a mixed germ cell-sex cord-stromal tumor with a concurrent interstitial cell tumor.     

Hyperinsulinism and hypoglycemia associated with pancreatic islet cell tumor in a ferret

Pancreatic islet cell tumor causing hypoglycemia and hyperinsulinism was diagnosed in a ferret with a history of progressive neurologic dysfunction. The diagnosis was suspected by the findings of hypoglycemia when the ferret was not fed, hyperinsulinism, and an amended insulin/glucose ratio approaching infinity. A focal pancreatic mass was removed by partial pancreatectomy, resulting in euglycemia and the resolution of clinical signs. Histologic diagnosis of the pancreatic mass was consistent with islet cell tumor (insulinoma). The ferret remained clinically normal for 8 months, but died after recurring episodes of hyperglycemia and glucosuria. Necropsy revealed no evidence of islet cell neoplasia involving the pancreas or other structures.     

Spontaneous Pancreatic beta cell tumor in the rat. A light and electron microscopic study.

Fine structural study of a pancreatic neoplasm found at autopsy of a 27-month-old female Long-Evans rat showed that the tumor consisted of, and derived from beta cells of the islets of Langerhans.     

Bleomycin chemotherapy for metastatic squamous cell carcinoma in a ferret.

Bleomycin, an antitumor antibiotic, was effective in temporarily reducing the size of a metastatic squamous cell carcinoma in a ferret. The tumor had recurred after previous excision and had metastasized to the right submandibular lymph node. The ferret was treated without effect at a dosage of 10 U/m2, sc, once a week. The dosage was increased to 20 U/m2 once a week, and reduction of tumor size was observed.     

Blastomycosis in a ferret

An 18-month-old female ferret with an ulcerated metacarpal pad and signs of respiratory illness was diagnosed as having blastomycosis by visualization of organisms on a tissue imprint, an agarose gel immunodiffusion test, and thoracic radiography. The ferret was treated intravenously with amphotercin B at 0.4 to 0.8 mg/kg and orally with ketoconazole at 8 mg/kg for approximately 1 month, during which time clinical and radiographic improvement was noted. A change to SC amphoterocin B therapy resulted in relapse of clinical signs despite continuation of ketoconazole therapy, and necessitated euthanasia. Necropsy revealed granulomatous lesions typical of Blastomyces dermatitidis infection in the lungs, thoracic pleura, spleen, meninges, and brain. Comparisons between this case and canine blastomycosis cases are made and alternative treatment regimes for mustelid blastomycosis are suggested.     

Hyperadrenocorticism in a ferret

A 7-year-old adult male ferret had progressive hair loss that was bilaterally symmetric. Also clinically evident were severe dehydration, polydipsia, muffled heart sounds, weak femoral pulses, hepatomegaly, lethargy, weakness, temporal muscular atrophy, dyspnea, and weakness. The blood profile of the ferret indicated profound leukopenia, eosinopenia, and high phosphorus, BUN, creatinine, and potassium concentrations, as well as high aspartate transaminase activity; the albumin concentration was low. The serum cortisol concentration was 8.1 micrograms/dl. Necropsy and histologic findings confirmed a diagnosis of hyperadrenocorticism, complicated by dilatative cardiomyopathy, chronic active hepatitis, and renal disease.     

Insulinoma in a ferret

Insulinoma was diagnosed in a 7-year-old female ferret examined because of generalized seizures, intermittent paraplegia, and abnormal behavior. Low serum glucose, high serum insulin, and infinite amended insulin/glucose ratio values in this ferret supported the clinical diagnosis of insulinoma. Histologic examination of the pancreas confirmed the diagnosis of insulinoma. The clinical signs and laboratory evaluations in this case and in a previously reported case of insulinoma in a ferret were consistent with variations reported in dogs with insulinoma.     

Polycystic kidneys in a ferret

Polycystic kidneys were found at necropsy in an adult ferret with a history of seizures and a palpable abdominal mass. Both kidneys contained numerous fluid-filled cysts of various sizes. The ferret may provide an animal model for the study of polycystic disease in man.     

Pregnancy toxemia in a ferret

A late-gestation jill was presented for depression, anorexia, and weakness. The working diagnosis became pregnancy toxemia. Supportive care was initiated and an emergency cesarian section performed. Twelve live kits were delivered; however, all soon perished despite home care. Surgery and recovery are discussed, including information regarding pregnancy toxemia in general.     

Renal adenocarcinoma in a ferret

A spontaneous case of renal tumor was observed in a 7-year-old ovariectomized female pet ferret (Mustela putorius furo). Clinical signs included exhaustion, emaciation, anorexia, and stooping position. At necropsy, a solid and cystic mass replaced the left kidney and adrenal gland. The tumor was composed of pleomorphic epithelial cells with a large number of giant cells. Metastases were recognized in the lung, liver, greater omentum, right renal pelvis, and systemic lymph nodes. Immunohistochemical stains revealed that the tumor cells were positive for CD10, cytokeratin (CAM 5.2), and Ki-67 (MIB-1). On the basis of morphologic and immunohistochemical features, the tumor was diagnosed as a pleomorphic renal adenocarcinoma. This type of neoplasm is very rare in all species and has never been reported in a ferret.     

Recurrent adenocarcinoma in a ferret

A 4.5-year-old, neutered male ferret with a history of recurrent adenocarcinoma in the preputial region was given 2 radiation treatment courses designed to control the rapidly growing neoplasm. The tumor regressed completely after the first 3.5-week course of therapy. The ferret remained clinically disease-free for 4 months, at which time small masses were noticed in the inguinal area and the original tumor site. A second course of therapy was administered, which again resulted in complete clinical regression of the neoplasm. However, the duration of remission was brief. Local recurrence and abdominal metastasis were observed within 2 months of the completion of therapy.     

Cryptococcus gattii chorioretinitis in a ferret

Bilateral exudative chorioretinitis was diagnosed in an 18‐month‐old male neutered ferret (Mustela putorius furo) with a generalized Cryptococcus gattii infection confirmed by PCR. The animal was referred to the Ophthalmology Service of the Autonomous University of Barcelona (VTH‐UAB) for acute onset blindness. Complete ophthalmic examination revealed absent menace response and dazzle reflex in both eyes (OU), as well as subretinal edema located in the tapetal fundus. At that time, the clinical ophthalmologic diagnosis was bilateral exudative chorioretinitis. Treatment with prednisone (0.5 mg/kg PO q24 h) was instituted in addition to the ongoing treatment with fluconazole (10 mg/kg PO q24 h). The following rechecks revealed secondary cataracts with subsequent lens subluxation and panretinal degeneration OU. Despite being blind and the poor prognosis of disseminate cryptococcosis, the patient remained active and in good body condition during 6 months after the initial diagnosis. At that time, the ferret showed ataxia, incontinence, and generalized pain. A magnetic resonance imaging study revealed a mass affecting the spine. The owners declined further investigations and the ferret was humanely euthanized. The postmortem histopathology confirmed the initial diagnosis of cryptococcosis and the presence of intraretinal Cryptococcus spp. To the authors’ knowledge, this is the first report of Cryptococcus spp. induced exudative chorioretinitis in a ferret.     

Thyroid follicular adenocarcinoma in a ferret

A 5-year-old male castrated ferret was presented to the Washington State University College of Veterinary Medicine for evaluation of progressive hair loss and a large, rapidly growing ventral neck mass. The patient had been diagnosed previously with an insulinoma, which was managed medically. Fine-needle aspirates of the neck mass were performed. The cytologic results were most consistent with epithelial neoplasia, likely a carcinoma; thyroid origin was considered likely based on tumor location and cell morphology. The tumor grew rapidly, and the owners elected euthanasia 1 week after examination. At necropsy, a circumscribed, ovoid mass disrupted the right cervical musculature next to the right lobe of the thyroid gland. Histopathologic evaluation revealed an infiltrative mass consisting of cuboidal cells arranged in solid sheets and irregular follicles enclosing colloid. The cells were large, with prominent nucleoli, and had a high mitotic rate. The histopathologic diagnosis was consistent with thyroid follicular adenocarcinoma. Immunochemical findings confirmed thyroglobulin production by neoplastic cells, but to a lesser extent than in normal ferret thyroid tissue. To our knowledge, this is the first case of thyroid follicular adenocarcinoma to be reported in a ferret, with only 1 other case of thyroid carcinoma, a C-cell carcinoma, described previously.     

Acute ibuprofen toxicosis in a ferret

A 20-month-old 1.44-kg (3.2-lb) castrated male ferret was examined because of vomiting, defecating in an abnormal location, dyspnea, and signs of depression. Within 5 minutes of initial evaluation, the ferret became nonresponsive to all stimuli except deep pain. Despite intensive supportive treatment, the ferret died. Toxicologic analyses for ibuprofen were performed on serum, urine, and liver, using gas chromatography and mass spectrophotometry. Serum ibuprofen concentrations were 245 micrograms/g before and 269 micrograms/g after death. Acute ibuprofen toxicosis may cause severe lethargy progressing to coma, apnea, and death in ferrets. Ibuprofen toxicosis should be considered in differential diagnoses for ferrets with signs of depression, with or without clinical signs of gastrointestinal tract dysfunction.     

Suspected pseudohypoparathyroidism in a domestic ferret

A 1.5-year-old ferret examined because of seizures was found to have low serum calcium, high serum phosphorus, and extremely high serum parathyroid hormone concentrations. Common causes of these abnormalities, including nutritional secondary hyperparathyroidism, chronic renal secondary hyperparathyroidism, tumor lysis syndrome, and hypomagnesemia, were ruled out, and a tentative diagnosis of pseudohypoparathyroidism was made. Pseudohypoparathyroidism is a hereditary condition in people that, to our knowledge, has not been identified in ferrets previously and is caused by a lack of response to high serum parathyroid hormone concentrations, rather than a deficiency of this hormone. The ferret improved after treatment with dihydrotachysterol (a vitamin D analog) and calcium carbonate. It was still doing well after 3.5 years of continued treatment.