Luteinizing hormone-dependent Cushing's syndrome in a pet ferret (Mustela putorius furo)

Hyperadrenocorticism in ferrets is associated with increased circulating concentrations of adrenal androgens, whereas plasma concentrations of cortisol and ACTH are usually not affected. Here, we report on a 5-year-old castrated male pet ferret (Mustela putorius furo) in which the major presenting signs were polyuria and polyphagia. Routine biochemistry values were within their reference ranges. The urinary corticoid:creatinine ratio (UCCR) was increased and the plasma ACTH concentration was suppressed. Abdominal ultrasonography revealed an enlarged right adrenal gland and atrophy of the left adrenal gland. Administration of hCG resulted in an increase of plasma cortisol and androstenedione concentrations. Based on these findings LH/hCG-dependent hypercortisolism and hyperandrogenism were suspected and treatment was started with a depot GnRH-agonist implant containing 9.4mg deslorelin. Within 3 weeks after placement of the implant all clinical signs had disappeared. Three months later the endocrine parameters had normalized, while abdominal ultrasonography revealed that the right adrenal gland had diminished in size and the left adrenal gland was considered of normal size. No recurrences of clinical signs were seen within 2 years after placement of the deslorelin implant. At that time urinary corticoid and plasma hormone concentrations were within their reference ranges, and no further change in the size of the adrenal glands was seen. In conclusion, this is the first confirmed case of LH-dependent hypercortisolism in a ferret that was treated successfully with a depot GnRH-agonist.     

Type 1 diabetes mellitus and hyperadrenocorticism in a ferret

Diabetes mellitus (DM) was diagnosed in a 6-year-old neutered male ferret with polyuria/polydipsia, symmetrical alopecia, and weight loss. Laboratory tests revealed severe hyperglycemia, glucosuria, and increased steroid hormone profile. Abdominal ultrasound revealed a bilateral enlargement of the adrenal glands. Significant clinical improvement was achieved with insulin- and leuprolide acetate-based therapy. After 2 months of therapy, the ferret showed a severe ketoacidosis, and the owner decided to euthanize the animal. Histological findings revealed carcinoma of the left adrenal cortex and cortical hyperplasia of the right adrenal gland. Moderate, chronic, and active pancreatitis with a marked decrease in the number of β-cells was also present. This is the first reported case of type 1 DM associated with hyperadrenocorticism and chronic pancreatitis in a ferret.

     

ADRENAL NEOPLASIA IN SEVEN FERRETS

Medical records from 7 ferrets presented to the VMTH with histologically confirmed adrenal neoplasia were reviewed. Three neutered female ferrets had adrenal cortical adenoma; four ferrets (2 neutered females, 2 neutered males) had adrenal cortical carcinoma. Ultrasound identified unilateral enlargement or abnormal shape of the adrenal gland in all ferrets. Only 1 ferret had adrenomegaly on abdominal radiographs. Adrenomegaly was identified in 1 ferret by magnetic resonance imaging (MRI). All ferrets were treated by adrenalectomy followed by a tapered dose of prednisone. Surgical complications were limited to fatal hemorrhage from the caudal vena cava in 1 ferret. Remission of clinical signs occurred in all 6 ferrets which survived surgery. The time of follow up varied from 3 to 16 months. The 3 ferrets with adrenal adenomas were still alive 3 to 7 months after surgery. AH 3 ferrets with adrenal carcinoma developed metastasis and were euthanized from 2 to 16 months after surgery.     

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.     

Adrenal adenoma in a cross-bred terrier

An adrenal tumour was diagnosed in a 12-year-old female cross-bred terrier. The dog was presented to the veterinary clinic because she had been gaining weight and had started urinating in the owners' house. Clinical findings included obesity, abdominal enlargement, thinning of the hair coat, seborrhoea sicca, and polydipsia and polyuria. The diagnosis was made by clinical pathology, endocrine function tests and abdominal radiography. Surgical removal of the neo-plastic right adrenal gland resulted in resolution of the clinical signs, including regrowth of the hair coat.     

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.     

Adrenal adenoma in a cross-bred terrier

An adrenal tumour was diagnosed in a 12-year-old female cross-bred terrier. The dog was presented to the veterinary clinic because she had been gaining weight and had started urinating in the owners' house. Clinical findings included obesity, abdominal enlargement, thinning of the hair coat, seborrhoea sicca, and polydipsia and polyuria. The diagnosis was made by clinical pathology, endocrine function tests and abdominal radiography. Surgical removal of the neoplastic right adrenal gland resulted in resolution of the clinical signs, including regrowth of the hair coat.     

Long-term outcome of domestic ferrets treated surgically for hyperadrenocorticism: 130 cases (1995-2004)

OBJECTIVE: To determine the long-term survival rate and factors that affect survival time of domestic ferrets treated surgically for hyperadrenocorticism. STUDY DESIGN: Retrospective case series. ANIMALS: 130 ferrets with hyperadrenocorticism that were treated surgically. PROCEDURES: Medical records of ferrets surgically treated for hyperadrenocorticism were reviewed. Data recorded included signalment, duration of clinical signs prior to hospital admission, CBC values, serum biochemical analysis results, anesthetic time, surgical time, concurrent diseases, adrenal gland affected (right, left, or both [bilateral]), histopathologic diagnosis, surgical procedure, caudal vena caval involvement (yes or no), postoperative melena (yes or no), days in hospital after surgery, and whether clinical signs of hyperadrenocorticism developed after surgery. RESULTS: 130 ferrets were entered in the study (11 of 130 ferrets were admitted and underwent surgery twice). The 1- and 2-year survival rates were 98% and 88%, respectively. A 50% survival rate was never reached. Combined partial adrenal gland resection with cryosurgery had a significantly negative effect on survival time. No other risk factors were identified. Survival time was not significantly affected by either histopathologic diagnosis or specific affected adrenal gland (right, left, or bilateral). CONCLUSIONS AND CLINICAL RELEVANCE: Ferrets with adrenal gland masses that were treated surgically had a good prognosis. Survival time of ferrets with hyperadrenocorticism undergoing surgery was not affected by the histologic characteristic of the tumor, the adrenal glands affected (right, left, or bilateral), or complete versus partial adrenal gland resection. Debulking was a sufficient surgical technique to allow a favorable long-term outcome when complete excision was not possible.     

Invasive histiocytic sarcoma of the lumbar spine in a ferret (Mustela putorius furo)

This report describes the history, clinical examination and histopathology of a histiocytic sarcoma in a domestic ferret. Clinical signs were acute paraplegia and dysuria. Physical examination revealed a firm, smooth, touch‐sensitive mass in and around the lumbar vertebral column. Neurologic examination was consistent with a lesion between spinal cord segments T3 and L3. Magnetic resonance images revealed bone lesions of L2 and L3 combined with compression of the spinal cord due to a homogenous, isointense mass that was diagnosed as a malignant round cell tumour and the ferret was euthanased. Histopathology confirmed the diagnosis of an infiltrative histiocytic sarcoma.     

Intervertebral disk prolapse in a ferret.

This case report describes the diagnosis and resolution of an inter-vertebral disk prolapse in a 6-year-old ferret. No predisposing causes were found in the patient's history. A right hemilaminectomy, performed 1 week after presentation, was chosen to treat the patient surgically, and complete remission of clinical signs was achieved 2 months after presentation.     

Surgical Management of Adrenal Tumors and Insulinomas in Ferrets

Domestic ferrets are popular pets and comprise a significant percentage of the caseload in many veterinary practices. This article describes the diagnosis and surgical techniques for treatment of 2 common endocrine disorders affecting ferrets, adrenal gland disease and pancreatic beta cell neoplasms. Although medical treatment options are used to reduce the severity of clinical signs associated with adrenal hyperplasia or neoplasia, surgical removal of the adrenal gland(s) is the treatment of choice. Clinical disease associated with pancreatic beta cell tumors includes hypoglycemia, and in many cases the tumor will metastasize early in the course of the disease. Although achieving a complete resolution of pancreatic beta cell neoplasia is unlikely, surgical removal of insulin-secreting tumors is recommended to temporarily alleviate the clinical syndrome and confirm the diagnosis.     

Thoracic vertebral chordoma in a domestic ferret (Mustela putorius furo).

A castrated adult male 1.0-kg domestic ferret (Mustela putorius furo) was referred for evaluation of a mass of >5 mo duration that was associated with the thoracic spine. The ferret had motor dysfunction and no conscious proprioception or pain perception in either hind limb. Segmental reflexes were present. Survey radiography, myelography, and magnetic resonance imaging showed a mass involving the ninth and 10 thoracic vertebrae and compressing the spinal cord. Decompressive surgery was performed, but clinical signs persisted. A diagnosis of chordoma was made using histopathology and immunohistochemistry. This is the first reported case of a chordoma involving the thoracic vertebrae in a domestic ferret.     

Subcutaneous neoplasms of the ventral abdomen with features of adrenocortical tumors in two ferrets

A ventral abdominal subcutaneous mass was removed from each of 2 young adult spayed female ferrets. In both cases, the neoplasms were composed of islands of polygonal cells separated by interlacing streams of spindloid cells reminiscent of ferret adrenocortical tumors with smooth muscle proliferation. Immunohistochemically, the polygonal cells demonstrated strong cytoplasmic reactivity for inhibin and weak cytoplasmic reactivity for pancytokeratin and S-100 protein. Spindloid cells demonstrated strong cytoplasmic reactivity for alpha smooth muscle actin, muscle-specific actin, desmin, and glial fibrillary acidic [corrected] protein. Ultrastructurally, the polygonal cells contained numerous intracytoplasmic clear vacuoles, mitochondria, scant rough endoplasmic reticulum, and few intermediate filaments. In one tumor, vesicular tubular mitochondria were found in polygonal cells. The spindloid cells contained numerous aggregates of parallel intermediate filaments. The histologic, immunohistochemical, and ultrastructural findings are suggestive of adrenocortical tumors with smooth muscle proliferation, but cannot be differentiated from an ovarian gonadal stromal tumor. Neither ferret had a clinically detected primary adrenal gland tumor or clinical signs of adrenal-associated endocrinopathy.     

ADRENAL ULTRASONOGRAPHY CORRELATED WITH HISTOPATHOLOGY IN FERRETS

The adrenal glands of twenty-six, 12-to 53-month-old, ferrets without clinical signs of adrenal disease were examined and measured by ultrasonography and the findings compared with those from gross examination and histopathology. Of 51 adrenal glands examined, 27 were normal, 23 had either nodular or diffuse cortical hyperplasia and 1 had an adenocarcinoma. There was no statistically significant difference between the sonographic nor gross size of normal adrenal glands and those with hyperplasia. Moderate correlation was found between gross and sonographic measurements of length for both right (r=0.783; p<0.0001) and left (r=0.609; p<0.001) adrenal glands; however, the sonographic measurements were less than the gross measurements. Correlation was found between the sex and weight of the ferret and adrenal gland length (p<0.01) and width (p<0.02). In female ferrets, the length, width, and depth of the right adrenal gland sonographically measured (mean±sd) 7.5±1.2 mm, 3.7±0.6 mm, 2.8±0.4 mm, respectively, and the left measured 7.4±1.0 mm, 3.7±0.4 mm, 2.8±0.4 mm; in males, the right adrenal measured 8.9±1.6 mm, 3.8±0.6 mm, 3.0±0.8 mm and the left measured 8.6±1.2 mm, 4.2±0.6 mm, 3.0±0.6 mm. Accessory adrenal tissue was not identified during the sonographic examination but was grossly found in 10 of the ferrets. It was associated with either the right, left or both adrenal glands.     

Adrenal gland disease in ferrets.

Adrenal gland disease in ferrets is unique to this species, with clinical signs and pathophysiology different from those seen in the dog. Its prevalence is increasing; 70% of pet ferrets in the United States were affected in 2003. The exact causes of the adrenal gland changes that lead to the disease are not known. Early oophorohysterectomies and neutering, combined with the artificially prolonged photoperiod experienced by indoor pet ferrets, and a possible genetic component, may be contributing factors. Signs of adrenal gland disease include progressive hair loss, pruritis, lethargy, atrophy, and, in female ferrets, vulvar swelling. An understanding of the signs and physiologic changes is necessary for diagnosis and treatment. A review of anatomy, physiology, and current surgical and medical options is presented.     

Distribution of Neospora caninum within the central nervous system and other tissues of six dogs with clinical neosporosis

Six cases of neosporosis in dogs were diagnosed on the basis of clinical signs, serology and immunohistochemistry. The brains and spinal cords, at several levels, and various other tissues were examined using anti-Neospora caninum serum by an immunoperoxidase technique. Parasite density varied markedly from case to case. Although found most consistently in the cerebrum, parasites were distributed throughout the central nervous system (CNS), both within the grey and white matter and within nerve roots. Clinical signs were not related to the position of parasites. Tissue cysts were found infrequently in all areas of the CNS, but not in other tissues. Parasite density was not related to the age of the dog or whether treatment had been given. However, with the exception of the only adult dog examined, more CNS parasites were found in dogs with a longer duration of illness and with higher antibody titres. Tachyzoites were present in skeletal muscles, in the muscularis of the oesophagus, in heart, lung and, less frequently, liver, and rarely in the adrenal gland, thyroid gland and uterus; no clinical signs were seen resulting from damage to these organs. Parasites were not observed in lymphoid tissue. In visceral organs, parasites were most widely distributed in peracute cases. For post mortem diagnosis of neosporosis, the CNS, particularly the cerebrum, is the optimum tissue to examine but parasites may also be found in many other tissues, especially in acute cases. Muscle biopsy of appropriate muscles (as suggested by the clinical signs) provides the possibility of a definitive pre-mortem diagnosis.     

Hyperadrenocorticism in six cats

The case records of six cats with hyperadrenocorticism presented to the Department of Clinical Veterinary Medicine, University of Cambridge, over an 11-year period were reviewed. Signalment and clinical signs were similar to previous reports but, in contrast to other reports, only three cats had diabetes mellitus on presentation. Abdominal radiographs revealed an adrenal mass in one case, obesity in all cases but no hepatomegaly. The adrenal glands were identified ultrasonographically in three out of six cases. Clinicopathological findings were non-specific. The diabetic cats had a significantly lower serum potassium concentration than the non-diabetic cats (P<0·05). Results of adrenocorticotrophic hormone (ACTH) stimulation tests were supportive of a diagnosis of hyperadrenocorticism in the five cats in which they were performed. Five cats had pituitary-dependent hyperadrenocorticism (PDH) and one had an adrenal tumour. Differentiation between the two forms of hyperadrenocorticism was possible preoperatively in five out of six cats. Adrenal histopathology confirmed hyperplasia in four cats and adenocarcinoma in one cat. Three cats with PDH underwent bilateral adrenalectomy and two of these cats had low, flat ACTH stimulation tests postoperatively and survived for significant periods. The cat with an adrenal tumour underwent partial unilateral adrenalectomy, maintained a positive ACTH stimulation test postoperatively and was euthanased one week after surgery.     

Hyperadrenocorticism and hyperprogesteronemia in a cat with an adrenocortical adenocarcinoma

A seven-year-old, neutered male domestic shorthair cat was evaluated for poorly regulated diabetes mellitus and increased skin fragility. Imaging studies revealed a right adrenal gland tumor, but cortisol testing did not support a diagnosis of hyperadrenocorticism. Serum concentrations of progesterone and testosterone were increased compared with a group of normal cats, and the clinical signs were attributed to hyperprogesteronemia. At necropsy, a diagnosis of adrenocortical adenocarcinoma was confirmed, and immunohistochemical staining confirmed the presence of progesterone within the tumor. Clinical signs of hyperadrenocorticism in cats may occur due to increased serum concentrations of hormones other than cortisol.