Castration for treatment of perianal gland neoplasms in the dog

Neoplasms of the perianal gland are common in the dog, particularly the male. Adenomas of the gland develop about 4.5 times more often than do carcinomas of the gland. The adenoma is hormone dependent; thus, castration without excision of the tumor has been successful in promoting regression without recurrence. Microscopic examination of the testes from dogs with perianal gland neoplasms has revealed 1 in 10 with tubular atrophy and 1 in 3 with testicular neoplasia. Interstitial cell tumors have been seen more often than other cell types of testis tumors.     

Metastases of perianal gland carcinoma in a dog: palliative tumor therapy

Palliative radiation therapy may provide significant relief in symptoms in pets with incurable cancer. Therapy is applied over a short period of time, using larger than normal fractional doses. Palliative radiation leads to minimal or no side effects. This case report describes the situation of a miniature poodle that was presented with severe dyschezia as well as fresh blood in the feces. The dog had a large abdominal mass which was diagnosed as lymph-node metastasis of a perianal gland carcinoma. Therapy included palliative radiation as well as chemotherapy. Six months after initial presentation the dog is free of clinical symptoms.     

A pleomorphic adenoma of the lacrimal gland in a dog

A 13-year-old female mongrel dog had a pleomorphic adenoma of the lacrimal gland in the right upper orbit. The tumor measured 3.8 x 3.0 x 3.3 cm, appeared white, round, and firm, and pressed the right globe and surrounding tissues. Histopathologically, the tumor had a thin connective tissue capsule and was composed of tubules with two cell types, some resembling luminal epithelial cells making up the tubular structures and the other of myoepithelial cells. Epithelial tubules were disposed in an adenomatous fashion and separated from each other by proliferating pleomorphic myoepithelial cells. Immunohistochemically, large numbers of the luminal epithelial cells revealed an immunopositive reaction against keratin/cytokeratin (AE1/AE3), and some epithelial cells reacted against cytokeratin 14. Spindle-shaped myoepithelial cells revealed an immunopositive reaction against cytokeratin 14, alpha-smooth muscle actin, and vimentin. A small number of myoepithelial cells reacted against desmin. S-100 protein immunopositivity was frequently found in luminal epithelial cells and rarely in the pleomorphic myoepithelial cells. Glial fibrillary acidic protein positivity was commonly found in myoepithelial cells, myxoid matrices, and intracystic materials, but not in luminal epithelial cells.     

Functional thyroid gland adenoma in a dog treated with surgical excision alone

An 11-year-old male Golden Retriever presented with progressive weight loss, tachycardia, hyperthermia, polyuria and polydipsia. A freely movable mass, 4.5 x 4 cm in size, was palpated at the cranioventral cervical region. Hormonal study revealed high levels of serum thyroid hormones, and a tentative diagnosis of hyperthyroidism due to a thyroid tumor was made. The tumor was removed surgically and diagnosed histopathologically as thyroid gland adenoma. Serum thyroid hormone levels decreased after surgery with improved clinical signs. At 12 months after surgery, the dog maintained a good physical condition with no evidence of recurrence.     

Efficacies of osaterone and delmadinone in the treatment of benign prostatic hyperplasia in dogs

A multicentre randomised clinical trial was performed to compare the therapeutic potential of osaterone acetate with that of delmadinone acetate in the treatment of benign prostatic hyperplasia in dogs. The osaterone was administered orally at 0.25 mg/kg bodyweight once a day for seven days to 73 dogs. The delmadinone was administered by a single intramuscular or subcutaneous injection at 3 mg/kg bodyweight to 69 dogs. During the 180-day trial, the dogs were monitored five times for their clinical signs and prostate volume. The two drugs were similarly effective in reducing the clinical signs and inducing complete clinical remission, and both induced a similar level of minor, mostly transitory adverse effects. Osaterone reduced the volume of the prostate glands of the dogs significantly more quickly than delmadinone.     

Immunohistochemical expression of heat shock proteins,p63 and androgen receptor in benign prostatic hyperplasia and prostatic carcinoma in the dog

This study compared heat shock proteins Hsp60, Hsp72 and Hsp73, along with p63 and androgen receptor (AR) immunoexpression between 16 cases of benign prostatic hyperplasia (BPH) and 11 prostatic carcinomas (PCa) in dogs. The proportion of Hsp60‐positive cells was higher in PCa compared with BPH (P = 0.033), whereas the frequency and intensity of Hsp73 immunostaining did not differ significantly between the two groups. Hsp72‐immunostained nuclei formed a discontinuous layer along the basement membrane in BPH, whereas cells in this layer in PCa were negative or weakly positive. Hsp72 nuclear score showed significant positive associations with both p63 (P = 0.016) and AR (P = 0.009) scores. Double immunofluorescence revealed Hsp72‐p63 and Hsp72‐AR co‐expressions in basal cell nuclei. Aberrant cytoplasmic p63 immunolabelling was observed in 3 of 11 PCa cases. These results suggest a role of the combined expression of Hsp72, p63 and AR in basal epithelial cells in canine BPH and PCa.     

Immune response in hormonally-induced prostatic hyperplasia in the dog

We induced prostatic enlargement in castrated dogs using either androgen alone or androgen combined with estrogen. In addition to previously reported hyperplastic changes, marked infiltration with immune effector cells was observed. This mononuclear cell infiltrate was phenotypically characterized using CD3 as pan T-lymphocyte marker, CD79 for B-lymphocytes, MAC378 for macrophages, and antibodies against kappa- and lambda-immunoglobulin (Ig) light chains for plasma cells. The majority of inflammatory cells (>80%) in the mononuclear infiltrates were T-lymphocytes and the numbers correlated with the degree of inflammation. The B-lymphocytes were found particularly in areas with marked follicular formation and diffuse infiltration, whereas there were only a few positive cells (<10%) in areas with a moderate or slight inflammation. Macrophages were found primarily in areas with atrophic and cystic changes with and without inflammation. The expression of lambda-Ig-positive cells depended on the degree of inflammation (5-10%), whereas immunoreactivity of kappa-Ig did not correlate with the extent of inflammatory reaction. Our present findings together with the evaluation of longitudinal biopsies of hormonally-induced BPH indicate that hyperplasia preceded cell-mediated and humoral immune response.     

Zygomatic gland adenoma in a dog: histochemical and immunohistochemical evaluation

Orbital epithelial tumors in dogs are rare and most frequently malignant. Distinguishing their origin from the lacrimal or zygomatic gland is often challenging and is based mostly on tumor location. A case of adenoma involving the orbit in a 13-year-old, female, standard Schnauzer is reported. Histologically, the neoplasm was characterized by nests and cords of epithelial cells mostly forming small glandular structures. The origin of the tumor from the zygomatic gland was determined by histochemical characteristics (alcian blue pH 1 positive staining) of a small remnant of normal gland included within the tumor capsule. The benign nature of our finding was confirmed by follow-up information: 2 years after complete surgical removal of the mass no tumor recurrence or metastases was recorded.     

Cyclosporine and ketoconazole for the treatment of perianal fistulas in dogs

OBJECTIVE: To evaluate efficacy and cost of using cyclosporine and ketoconazole for the treatment of perianal fistulas in dogs. DESIGN: Clinical trial. ANIMALS: 12 dogs with perianal fistulas. PROCEDURE: Dogs received cyclosporine and ketoconazole orally (target whole blood trough cyclosporine concentrations of 400 to 600 ng/ml). Study endpoints were resolution of clinical signs, remission, and recurrence of disease. Adverse effects and cost of medications were reported. Results were compared with those from previous studies in humans and in dogs in which single agent cyclosporine treatment for perianal fistulas was used. RESULTS: All dogs had resolution of clinical signs. Eight dogs went into remission; however, 5 of those 8 had recurrence of fistulas. Adverse effects of treatment were minimal and well tolerated. Cost of treatment was comparable to traditional surgical options and less than single agent cyclosporine treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of cyclosporine with ketoconazole is an effective and cost-comparable treatment for perianal fistulas in dogs.     

Carcinoma ex pleomorphic adenoma with sebaceous differentiation in the mandibular salivary gland of a dog

A carcinoma ex pleomorphic adenoma was diagnosed in the left mandibular salivary gland of an 8-year-old female spayed dog. The animal presented with a large nonpainful swelling in the left submandibular region. A computed tomography scan detected an irregularly enhancing soft tissue mass that was closely associated with the left external ear canal and extended to the left wing of the atlas. On surgical exploration, the mass was intimately associated with the left mandibular salivary gland. Both the mass and the adjacent gland were removed, and the diagnosis was determined by histopathology. The tumor was comprised of basaloid and low columnar epithelial cells, many glandular units formed by well-differentiated sebocytes, and multifocal regions of necrosis, mineralization, and hemorrhage. Salivary gland tumors with sebaceous differentiation are very rare in animals, with one previously reported case in a cat.     

Duodenal Brunner's gland adenoma causing chronic small intestinal obstruction in a dog

An eight-year-old, neutered, female English springer spaniel was presented with a 14-month history of vomiting, marked weight loss and lethargy, all of which were non-responsive to medical therapy. Abdominal radiographs and ultrasonography showed an intraluminal soft tissue mass extending from the pyloric antrum to the proximal duodenum. Two spherical masses both approximately 8 cm in diameter were removed via a duodenotomy. Histopathological examination showed the first mass to be a trichobezoar and the aboral mass to be a Brunner's gland adenoma. Surgery resulted in a complete resolution of the clinical signs.     

犬外耳道耵聍腺腺瘤的病理学诊断

通过临床观察、组织学诊断结合免疫组织化学染色对一例犬外耳道肿瘤进行病理学诊断。本病例为13岁雄性苏格兰牧羊犬,肿瘤发生于左侧外耳道,眼观肿物呈灰白色,形成乳头状结节,与周围组织界限清晰。组织学观察可见结缔组织将实质分成小的囊状结构;实质细胞增生,呈典型的顶浆分泌性腺体结构,核大而圆,异型性小,形成乳头状突起;间质中有多量的血管,并伴有炎性细胞浸润。免疫组织化学中的CK染色发现增生的实质细胞为上皮细胞,而通过SMA染色可见腺上皮被覆一层完整的肌上皮细胞。通过以上诊断方法确定该犬患为外耳道耵聍腺腺瘤。     

Urethral prosthesis for treatment of prostatic abscess in a dog

A dog with a prostatic abscess was treated successfully with surgical implantation of a urethral prosthesis after 6 recurring episodes of abscess formation failed to respond to antibiotic therapy, surgical drainage, and bilateral marsupialization.     

High plasma estradiol-17beta levels in dogs with benign prostatic hyperplasia and azoospermia

The semen quality of 22 dogs (4 to 7 years old) with benign prostatic hyperplasia (BPH) was examined at the hospital of our university, and 4 of the 22 BPH dogs were diagnosed as azoospermic. The mean peripheral plasma estradiol-17beta (E2) level (17.3 pg/ml) of the 18 BPH dogs with spermatogenic function was higher than that of 5 normal male dogs and their mean T level (1.7 ng/ml) was lower. The mean E2 level (27.3 pg/ml) of the 4 BPH dogs with azoospermia was significantly higher than the value in the BPH dogs with spermatogenic function (P<0.01), and the mean T level (1.1 ng/ml) was significantly lower (P<0.05). Five normal male dogs were given 10 intramuscular injections of estradiol benzoate (E2B) 5 microg/kg, at 3-day intervals to investigate the relationship between high plasma E2 levels and the cause of the BPH and azoospermia. Their testes and prostates were measured and biopsied both before and 30 days after the start of E2B injections. At 30 days after the start of the E2B injections, the mean peripheral plasma T levels had decreased by half, and the mean testicular volume had decreased to 88% of original volume. The numbers of spermatocytes, spermatids, and spermatozoa in the seminiferous tubules of all of the dogs were significantly lower (P<0.05, 0.01). In addition, the mean prostatic volume increased to 130%, the mean height of the glandular epithelium decreased, and the glandular lumen became increased in diameter. These findings indicate that both BPH and serious spermatogenic dysfunction may be simultaneously induced by protracted high plasma E2 levels in dogs.     

Primary hyperaldosteronism in a dog with concurrent lymphoma

An 11-year-old, male castrated English springer spaniel was presented for muscle weakness, lethargy and anorexia while undergoing treatment of Stage IV lymphoma. Persistent hypokalemia prompted multiple diagnostic tests. Serum aldosterone levels, surgical exploration and histopathology confirmed primary hyperaldosteronism. Hyperaldosteronism is a rarely reported endocrinopathy in the dog. This report describes a case in which immunohistochemistry was utilized to confirm the diagnosis of an aldosterone-secreting tumour.     

Hyperthyroidism associated with a thyroid adenoma in a dog

Hyperthyroidism associated with thyroid adenoma was diagnosed in a dog. Typical clinical signs of hyperthyroidism were resolved with surgical excision of the adenoma. Hyperthyroidism in dogs usually is associated with thyroid carcinoma, which has a poor prognosis. This case emphasizes the importance of obtaining a histologic diagnosis of thyroid tumors in hyperthyroid dogs before giving a prognosis.