Malignant melanoma in the foot of a horse

A 24-year-old horse had a malignant melanoma of the right forefoot. Because surgical excision of the melanoma was incomplete, as determined by histologic examination of the excised tissue margins, the tumor margins were injected with a matrix therapeutic implant containing cis-diamminedichloroplatinum, epinephrine, and purified bovine collagen matrix. The foot healed and the horse remained clinically free of disease for 26 months before recurrence of malignant melanoma. Surgical exploration of the digit revealed extensive involvement of the foot, and the horse was euthanatized.     

Ultrasonographic evaluation of the adrenal glands in healthy dogs: repeatability, reproducibility, observer-dependent variability, and the effect of bodyweight, age and sex

Adrenal length and width were determined from two-dimensional ultrasound longitudinal images. In study 1, 540 measurements of adrenal glands were attempted from five healthy beagle dogs by three different observers with different levels of expertise in ultrasonography, to determine the variability of adrenal gland measurements. Of these, 484 measurements were included in the statistical analysis, since 16 measurements of the left adrenal gland and 40 for the right could not be visualised by the observer. In study 2, a single measurement of both adrenal glands was taken from each of 146 dogs by the most trained observer from study 1, and the effects of different health status (healthy dogs v dogs with non-adrenal diseases), bodyweight, age and sex were assessed. A total of 267 measurements were included in the statistical analysis. The lowest intra- and inter-day coefficient of variation values were observed for the left adrenal gland and by the most trained observer. The health status had no statistically significant effect on adrenal gland length or width, whereas age had a significant effect only for the left adrenal gland (the greater the age, the greater the width or length) and sex had a significant effect only for the right adrenal gland (the width was larger in males and the length larger in females). The bodyweight had a significant effect for the length of both adrenal glands (the greater the bodyweight, the greater the length), but not the width. The differences between sd and coefficient of variation values for the width of the left adrenal gland were not statistically significant between the three observers, whereas they were statistically significant for the right adrenal gland.     

Acute myelomonocytic leukemia in a horse

A 7-year-old Quarter Horse stallion with a myeloproliferative disorder was examined because of colic, and an enterolith was removed surgically. The horse experienced secondary complications after abdominal surgery, and leukopenia and thrombocytopenia were detected. Five months later, the horse was examined for recurrent peripheral edema and for repair of an abdominal incisional hernia. Acute myelomonocytic leukemia was diagnosed, and treatment with low-dose (noncytocidal) cytosine arabinoside was unsuccessful. Necropsy revealed neoplastic infiltrate in the spleen, liver, lung, adrenal gland, testes, and eye. The persistent hematologic abnormalities before the onset of overt leukemia may represent hematopoietic dysplasia or preleukemia.     

ULTRASONOGRAPHIC DETECTION OF ADRENAL GLAND TUMOR AND URETEROLITHIASIS IN A GUINEA PIG

A 5-year-old guinea pig was presented to the University of Berne Small Animal Radiology Department for an ultrasound examination of the abdomen to confirm a suspected diagnosis of Cushing's syndrome. The patient had bilateral alopecia, was apathic and obese. Ultrasonographically, a tumor of the left adrenal gland, obstruction of the left ureter by an ureterolith, as well as hydronephrosis of the left kidney were detected. During surgery to relieve the ureteral obstruction the adrenal gland tumor was removed. The guinea pig died post-operatively due to blood loss. The left adrenal gland tumor was found histopathologically to be an adenoma and the right adrenal gland also had multiple small adenomas, but grossly appeared normal. The ureterolith was analyzed and found by x-ray diffraction to consist of calcium carbonate.     

Three neoplasms in a Eurasian otter (Lutra lutra): malignant melanoma,trichoblastoma and mammary gland adenoma

An eighteen-year-old female Eurasian otter became emaciated and died. Necropsy examination revealed nose and thoracic cutaneous masses, abdominal subcutaneous mass, and multiple nodules in the liver and lungs. Malignant melanoma was found in the nose cutaneous mass and to have metastasized to the liver, lungs, kidneys, adrenal glands, mammary glands and left mandibular lymph node. The neoplastic cells were labeled for vimentin, melanoma, and S100. The cutaneous mass in the thoracic area consisted of spindle shaped neoplastic epithelial cells and was diagnosed as trichoblastoma. Mammary gland adenoma was observed in the abdominal subcutaneous mass. This is the first report of primary three neoplasms of malignant melanoma, trichoblastoma and mammary gland adenoma in a Eurasian otter.     

Four cases of neoplasia in captive wild birds

Four cases of malignant neoplasia in captive wild birds are described: an adenocarcinoma of the adrenal gland in a Mountain duck (Tadorna tadornoides), a malignant melanoma in the thoracic cavity of a Combed duck (Sarkidiornis melanotos), a hepatocellular carcinoma with pulmonary metastasis in an Asian Purple Swamphen (Porphyrio porphyrio), and an undifferentiated carcinoma in the abdomen with metastasis to skeletal muscle in a White-Breasted Waterhen (Amaurornis phoenicurus). The tumors were diagnosed during a 1-year period and represented an incidence of neoplasia of 3.1%. These appear to be the first documented cases of a malignant adrenal gland tumor and a non-ocular melanoma in the order Anseriformes. The hepatocellular carcinoma failed to react with an immunoperoxidase stain for alphafetoprotein.     

Primary sinonasal malignant melanoma with systemic metastasis in a non-gray horse

A 27-y-old Anglo-Arabian gelding with bay coat color was presented with a swelling of the left maxillary region. Fenestration on the left maxilla revealed that the left maxillary sinus was filled with black-red tissue. A portion of the tissue was excised and diagnosed histologically as malignant melanoma. Genotyping of the STX17 gene for gray coat color revealed that the horse did not have the “gray” factor. The horse was euthanized ~3 mo after first presentation. During autopsy, a black-to-gray mass extended from the left nasal cavity to the surrounding paranasal sinus and invaded the hard palate, cribriform plate, and the cranial portion of the left olfactory bulb. Moreover, identical black nodules were present in lymph nodes from the mandible to the larynx, and in the spleen, liver, kidney, and adrenal glands. However, masses were not found in the skin, perineal region, or pelvic cavity. All of the black-to-gray nodules were malignant melanomas that were histologically identical to the initial biopsy; tumor emboli were also found in the kidney. Sinonasal mucosal melanoma is a rare disease in horses.     

Multiple myeloma in a horse

Multiple myeloma was diagnosed in a 22-year-old Arabian mare with a history of chronic weight loss. Quantitative immunoglobulin analysis revealed monoclonal gammopathy (IgG(T), 9,800 mg/dl). Due to progressive weight loss, the horse was euthanatized. Microscopy of tissues revealed plasma cell infiltrates in bone marrow, spleen, pituitary gland, adrenal cortex, muscle of the tongue, and bronchial, renal, and mesenteric lymph nodes.     

Use of x-ray-computed tomography as an aid in localization of adrenal masses in the dog

Four dogs with clinical evidence of hyperadrenocorticism were evaluated by use of x-ray-computed tomography (CT). Adrenal masses were identified accurately and localized. Unilateral adrenal masses were diagnosed accurately in dogs 1, 2, and 3 and were removed surgically via a paracostal retroperitoneal approach to the adrenal gland. Using CT and IV contrast medium, the adrenal mass in dog 3 also was accurately diagnosed as being highly vascular. The histopathologic diagnosis was adrenal adenoma in dogs 1, 2, and 3. In dog 4, the CT-roentgen diagnosis was asymmetric bilateral adrenal enlargement. Necropsy examination of dog 4 indicated moderate enlargement of the left adrenal gland and severe enlargement of the right adrenal gland. Results of microscopic examination indicated chronic inflammation of the left adrenal gland and adenocarcinoma of the right adrenal gland. Use of CT facilitated localization of adrenal masses and fulfilled the needs of a localizing technique. A unilateral mass can be removed surgically via a limited exposure, retroperitoneal incision on the affected side of the animal instead of removal via abdominal laparotomy, which is more invasive. Advantages of CT can reduce the needs of other imaging modalities for the localization of adrenal masses.     

Malignant melanoma of the coronary band in a horse

A malignant melanoma developed in the digit of a horse. Metastasis was extensive.     

Ultrasonographic adrenal gland measurements in clinically normal small breed dogs and comparison with pituitary-dependent hyperadrenocorticism

Ultrasonography is a sensitive and specific screening method for assessing the adrenal glands. The upper limit of the normal adrenal gland width is used as 7.5 mm. It is not known if adrenal gland width remains consistent with body weight. A reliable criterion of adrenal gland width in small breed dogs should be established. Small breed dogs with body weights of less than 10 kg were divided into two groups: 189 normal dogs and 22 dogs with pituitary-dependent hyperadrenocorticism (PDH). A retrospective study was conducted on dogs seen between January 1, 2006, and February 10, 2008. One hundred eighty-nine dogs of 14 different small breeds were enrolled in the normal adrenal gland group; the median gland width was 4.20 mm. Twenty-two dogs were in the PDH group; the median gland width was 6.30 mm. The cut-off value between normal adrenal glands and PDH was 6.0 mm. This figure gave a sensitivity and specificity of 75 and 94%, respectively, for detecting PDH. The adrenal gland appeared as a peanut shape with homogeneous hypoechoic parenchyma in normal dogs and in most dogs with PDH as well. This study was performed in a large population of small breed dogs and suggests that the normal adrenal gland size in small breed dogs is smaller than previously reported. We believe that a cut-off of 6.0 mm may be used as the criterion for differentiating a normal adrenal gland from adrenal hyperplasia.     

Ultrasonographic measurement of the adrenal gland-to-abdominal aortic ratio as a valuable method of estimating normal adrenal size in rabbits

A wide range has been reported for the ultrasonographic measurements of the normal adrenal gland in rabbits. Therefore, having sufficient information about the normal measurements of the adrenal gland and their relationship with indicators such as weight, sex and the diameter of the internal abdominal aorta will be of great help in diagnosing diseases of the adrenal gland. In the present study, 21 healthy adult intact rabbits were selected. The abdominal cavity of the animals was examined using ultrasound; adrenal gland parameters such as length, width, height, circumference and area on the right and left sides were measured in both sagittal and transverse planes. Additionally, the diameter of the abdominal aorta in the sagittal plane was imaged. After statistical analysis, the parameters of the adrenal glands on the right and left showed a positive significant correlation with the weight and the diameter of the abdominal aorta, although no significant correlation was found between these parameters and sex. The ratio of adrenal gland parameters to abdominal aortic diameter was calculated and the statistical analysis of the values showed that, except for the ratio of left adrenal area to aortic diameter, the other ratio of adrenal gland parameters to abdominal aortic diameter was not significantly related to weight. Therefore, these ratios can be used as suitable indicators for assessing the change in size of the adrenal gland of rabbits of different sizes. Knowing the relationship between normal adrenal measurements and the indices such as weight, sex and diameter of the abdominal aorta can help clinicians and researchers evaluate the changes in the size of the adrenal gland.     

Conjunctival malignant melanoma in a horse

A case of malignant melanoma originating from the conjunctiva of a horse is reported. The tumor exhibited locally aggressive behavior as evidenced clinically by recurrence following two treatment episodes including surgical excision on each occasion and one application of cryotherapy. The orbit was subsequently exenterated and histologically malignant conjunctival melanoma was confirmed. Histopathologic features included variable pigmentation with amelanotic sites demonstrating marked cellular and nuclear pleomorphism with high numbers of mitotic figures. Cords of neoplastic cells invaded the sclera and cornea. Following exenteration, the horse exhibited no recurrence of the tumor for five years before being lost to follow-up. To our knowledge, this is the first report of primary malignant conjunctival melanoma in a horse.     

Tail-base mass from a "horse of a different color"

A 14-year-old bay Thoroughbred gelding was presented for evaluation of a mass at the base of the tail. The mass had been present for 1 year, and recently had begun to increase in size. Additional masses were found around the eye and shoulder. A fine-needle aspirate of the tail-base mass revealed highly anaplastic round to polyhedral cells containing dark green to black cytoplasmic granules interpreted to be melanin. Histologically, the mass was composed of pleomorphic, poorly pigmented, round to polyhedral cells interpreted to be neoplastic melanocytes. With immunohistochemistry, the cells were positive for vimentin and S-100, but negative for pancytokeratin and Melan-A. The cytologic and histopathologic diagnoses were amelanotic melanoma. The horse was treated with cimetidine, but the tumor continued to progress. In this report, we describe the cytopathologic features of an aggressive amelanotic melanoma in a non-grey horse and emphasize the unique correlation between cytologic and histologic findings.     

Ultrasonographic evaluation of the adrenal glands in six dogs with hypoadrenocorticism.

The purpose of this study was to determine the value of ultrasonographic characterization of the adrenal glands in dogs with hypoadrenocorticism. Measurements of adrenal glands were obtained in six dogs with hypoadrenocorticism. The adrenal glands on both sides were shorter (range: left adrenal gland length, 10.0 to 19.7 mm; right adrenal gland length, 9.5 to 18.8 mm) and thinner (range: left adrenal gland thickness, 2.2 to 3.0 mm; right adrenal gland thickness, 2.2 to 3.4 mm) than in normal dogs (range: left adrenal gland length, 13.2 to 26.3 mm; right adrenal gland length, 12.4 to 22.6 mm; left adrenal gland thickness, 3.0 to 5.2 mm; right adrenal gland thickness, 3.1 to 6.0 mm). Statistical analysis revealed a significant reduction in size of the left adrenal gland (p less than 0.05) in dogs with hypoadrenocorticism compared to the left adrenal gland in normal dogs. The results of this study show that atrophy of the adrenal glands in dogs with hypoadrenocorticism seems to lead to an ultrasonographic-measurable reduction in size of the adrenal glands.     

Hemithyroidectomy in a horse with confirmed hyperthyroidism

A 23-year-old Quarter Horse gelding was admitted to the hospital because of cachexia and hyperactive behavior of 1 year's duration. At admission the horse was severely emaciated, tachycardic with a grade V/VI diastolic murmur, pyrexic, polydipsic, enophthalmic, and alopecic. The right lobe of the thyroid gland was noticeably larger than typical. The horse was also hyperexcitable and had a ravenous appetite. A presumptive diagnosis of hyperthyroidism was made on the basis of clinical signs and high plasma thyroid hormone concentrations. Confirmation of the diagnosis was made on the basis of results of a triiodothyronine-suppression test. Following endocrine testing, the affected portion of the thyroid gland was removed and identified histologically as an adenoma. Return or plasma thyroid hormone concentrations to reference range values and resolution of the clinical signs of disease following hemithyroidectomy provided further conformation of the diagnosis. On the basis of finding in this horse, it appears that horses with hyperthyroidism may be successfully treated by hemithyroidectomy.     

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.     

Effects of mitotane therapy in dogs with pituitary dependent Cushing syndrome on the adrenal gland size--an ultrasonographic study]

The effect of mitotane therapy on adrenal gland size was evaluated in 13 dogs with pituitary dependent hyperadrenocorticism. Ultrasonographic measurements were obtained before and during mitotane therapy. During therapy both adrenal glands were shorter and thinner (median during therapy: left adrenal gland 19.4 mm long, 5.4 mm thick, right adrenal gland 18.1 mm long, 6.1 mm thick) than before mitotane therapy (median before therapy: left adrenal gland 23.6 mm long, 8.3 mm thick, right adrenal gland 21.6 mm long, 8.1 mm thick). Statistical evaluation showed a significant reduction in size. But ultrasonographic measurement of adrenal gland size is not useful in the evaluation of adrenal reserve during mitotane therapy. Inadequate adrenal reserve was not identified and adrenal size measurement by ultrasonography was not helpful to differentiate adequate and inadequate control of adrenal cortisol secretion during mitotane therapy.     

Evaluating the correlation between adrenal gland dimensions and aortic diameter in healthy dogs

In the present study, the relationship of normal adrenal dimensions with weight, aortic diameter, age and sex was evaluated. Moreover, a formula for estimating the normal dimensions of adrenal gland was provided. Thirty‐two intact adult dogs that were considered healthy based on history, physical examination, routine blood works and specific adrenal tests as well as absence of any abnormal ultrasonographic findings were included. Adrenal glands and abdominal aorta were imaged in the sagittal plane by ultrasound. Length, maximal height of the cranial and caudal poles, area and circumference of the left and right adrenal glands and also the internal diameter of the abdominal aorta were measured. Analysis showed that there is a positive correlation between the adrenal gland dimensions and weight and aortic diameter. The ratio of adrenal gland dimensions and the aortic diameter was calculated, but this ratio showed a great amount of variability in tandem with a significant correlation to the weight; Meaning that the ratio of the adrenal gland dimensions to the aortic diameter was not a reliable index for evaluating the size of the normal adrenal gland in animals with different weights. Therefore, we used the weight along with adrenal measurements in a linear regression model, and then, we were able to estimate the adrenal gland dimensions in different weights. Knowing the relationship of normal adrenal dimensions with the indices such as weight, age, sex and diameter of abdominal aorta can help the clinicians to diagnose the adrenal gland diseases.     

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.