Polycystic kidney disease in goldfish (Cusrassius auratus)

Abstract Thirty percent of 60 goldfish in an outside pond showed progressive development of swollen abdomens and floatation problems. The occasional fish was found dead. Necropsy of an affected fish showed an abdomen almost filled with a large bilobed ventral mass comprised of masses of cysts filled with clear fluid. On histopathological examination, this mass appeared to be composed of large cystic spaces lined by a single flattened epithelium. Occasional remnants of normal kidney tissue were seen withen the mass.     

Radiographic,ultrasonographic, and computed tomographic characteristics of an accessory liver lobe in a cat

A 5‐year‐old male Norwegian Forest cat presented with increased hepatic serum biochemical parameters. Abdominal radiography showed an oval cranioventral mass and ultrasound revealed a mobile mass attached to one hepatic lobe. Computed tomography (CT) confirmed that the mass was attached to the right medial liver lobe. Differential diagnoses were an accessory liver lobe, benign neoplasia, and focal nodular hyperplasia. The mass was removed and histopathology confirmed the mass to be normal liver tissue. Accessory liver lobe should be included in the differential diagnosis of a mobile cranial abdominal mass with a similar ultrasonographic or CT appearance to the liver.     

Polycystic kidney disease in goldfish (Cusrassius auratus)

Thirty percent of 60 goldfish in an outside pond showed progressive development of swollen abdomens and floatation problems. The occasional fish was found dead.

Necropsy of an affected fish showed an abdomen almost filled with a large bilobed ventral mass comprised of masses of cysts filled with clear fluid. On histopathological examination, this mass appeared to be composed of large cystic spaces lined by a single flattened epithelium. Occasional remnants of normal kidney tissue were seen withen the mass.     

Surgical removal of a canine orbital lipoma

A 10-year-old, female, neutered Cairn terrier was presented with a progressively enlarging, cream-white fluctuant subconjunctival swelling in the right eye. A fine-needle aspirate performed under topical anaesthesia showed that the mass contained lipomatous tissue. Orbital ultrasonography showed the mass to have a distinct border and to extend into the posterior orbit. The mass was removed via a conjunctival incision. It had a distinct capsule anteriorly, while the border of the mass was less readily identified in the posterior orbit. Histopathological examination showed the mass to be a lipoma. The dog recovered uneventfully from surgery, and no recurrence has been noted after 12 months.     

Alveolar rhabdomyosarcoma of the limb in a sheep

Tumor mass was detected in the skeletal musculature of the tibia in a sheep slaughtered at abattoir. Histologically, the tumor cells were in a typical alveolar pattern, and showed a cartilaginous tissue differentiation in some areas of the tumor mass. This tumor examined by avidin-biotin-peroxidase method was found to be positive for myoglobin. The diagnosis of undifferentiated alveolar rhabdomyosarcoma was based on the results of histopathology and immunohistochemistry.     

Subcutaneous hemangiosarcoma induced by a foreign body (steel staple) in a cat

An 8-year-old, female domestic shorthair cat was presented with a ventral abdominal subcutaneous mass. A radiograph showed that the center of the mass contained what appeared to be steel sutures, presumed to be from an ovariohysterectomy performed 7 years earlier. The excised mass was irregular and contained numerous pockets filled with friable necrotic material and hemorrhages that were dissected by fibrous connective tissue bands. Multiple tangled and fragmented pieces of steel staples were deeply embedded within the mass. Histologically, the mass was non-encapsulated, densely cellular, and infiltrative. Neoplastic cells lined caverns and channels and were factor VIII-positive by immunohistochemistry. The neoplastic cells were oval to round with granular cytoplasm and vesicular nucleus and exhibited moderate cellular and nuclear pleomorphism. A diagnosis of subcutaneous hemangiosarcoma was made. To our knowledge, this is the first report of foreign body associated hemangiosarcoma and the first case of steel staple associated neoplasm in domestic animals.     

Surgical resection of a dysgerminoma in a mare

A mare was referred for further evaluation of a mass found in the left caudal abdomen during a routine postpartum reproductive palpation. The mare was clinically normal with no history of health problems. Ultrasonographic examination of the mass confirmed its presence, but the origin of the mass could not be accurately determined. Routine haematology and serum biochemistry results were within normal limits. The mare was initially treated conservatively with antibiotics, but the mass continued to increase in size, so it was surgically excised. The mass involved the left ovary. The mare showed transient abdominal pain after surgery, but developed no other complications and was in foal 7 months later. On histology, the mass was diagnosed as a dysgerminoma, a rare ovarian tumour of germ cell origin.     

Three cases of canine gastrointestinal stromal tumors with multiple differentiations and c-kit-expression

Three canine gastrointestinal stromal tumors (GISTs) were examined. Histopathologically, the tumor mass in the jejunum (Case 1) consisted of the proliferation of epithelioid cells with abundant eosinophilic or vacuolated cytoplasm. Gangliocyte-like or multinucleated giant cells were scattered. The tumor cells exhibited neural natures mimicking human gastrointestinal autonomic nerve tumors, which were immunopositive for several neuronal markers. Another jejunal mass (Case 2) was composed by a solid proliferation of spindle-shaped cells, arranging in interlacing fascicles and occasional storiform pattern. The tumor seemed to be classified undifferentiated GISTs, that showed no apparent neural or muscular features by ultrastructural and immunohistochemical examinations. In the pyloric mass (Case 3), the spindle cells having eosinophilic processes and elongated nuclei were arranged in sheets. Immunohistochemically, the tumor cells showed muscular natures as regards alpha smooth muscle actin and desmin expression.     

Megaesophagus was complicated with Billroth I gastroduodenostomy in a cat

A seven-year-old, female, domestic short hair cat was presented with a history of chronic anorexia. Radiographic examination revealed a large space-occupying calcified mass in the abdominal cavity. The mass was located in pylorus and did not extend into the duodenum and surrounding tissues. Billroth I gastroduodenostomy was conducted to remove the mass. Histopathological examination of the mass showed a lymphoma. Although Recovery following the operation was excellent, the patient showed intermittent vomiting unrelated to feeding. Radiographical examination revealed a megaesophagus, which was assumed to be a complication of the Billroth I procedure, since the condition was not observed before the procedure.     

Uterine leiomyosarcoma and pyometra in a dog

A seven-year-old entire female, mixed-breed dog, weighing 19 kg, was presented with a 2-day history of abdominal distension, reduced appetite and general dullness. Abdominal palpation revealed a large mass. Radiography showed a large mass occupying the left mid-abdominal area and convoluted loops of tubular fluid opacity occupying the right mid-abdominal area. Ultrasonography revealed a large heterogeneous mass with an anechoic area and some hyperechoic foci, indicative of calcification, in the mid-abdominal area. Furthermore, hypoechoic areas were found in the middle and caudal abdominal area and were presumed to be the fluid-filled uterine horns. At laparotomy, a 10·5×14·5-cm firm mass was found in the uterine body, while the uterine horns were filled with a thick red-brownish exudate; ovariohysterectomy was subsequently performed. A diagnosis of uterine leiomyosarcoma associated with pyometra was established by histopathology and immunohistochemistry.     

Abscess of bovine brain stem diagnosed by contrast MRI examinations.

A 3-month-old, female Japanese Black calf that showed signs of neurological dysfunction soon after birth was twice examined by magnetic resonance imaging (MRI). Survey MR images showed changes in a hydrocephalus from mild to severe and the existence of a mass above the brain stem that could be distinguished from the surrounding cerebral parenchyma. Contrast MRI examinations using Gd-DO3A-butriol showed the mass to have a doughnut-like form. As the mass changed, the clinical signs aggravated. We diagnosed a brain stem abscess, which we confirmed pathologically. To our knowledge there are no other reports of the use of contrast MRI to examine cattle.     

Ascites in a 13‐year‐old miniature horse mare with an ovarian granulosa theca‐cell tumour: A manifestation of Meigs' syndrome?

A 13‐year‐old miniature horse mare presented for evaluation of ascites. Abdominal ultrasound showed severe free peritoneal fluid accumulation as well as a caudal abdominal mass. The peritoneal fluid was characterised as a transudate with no evidence of sepsis. Surgical exploration of the abdomen was performed; copious free peritoneal fluid and a large right ovarian mass were discovered. The abnormal ovary was removed, and the mass was determined histologically to be a benign granulosa theca‐cell tumour. Although there was mild peritoneal fluid accumulation in the immediate post operative period, the ascites effectively resolved with removal of the tumour, and the mare returned to a normal lifestyle. This is similar to reports of Meigs' syndrome in human women, in which a benign ovarian mass of significant size causes ascites that resolves once the mass is removed.     

Energetic Requirements for Growth and Maintenance of the Cape Gannet (Aves; Sulidae)

Energetic requirements for growth and maintenance of the Cape gannet (Sula capensis) were studied by hand-rearing captive chicks and keeping juveniles in captivity at constant mass. Daily gain in mass was linear until 60 days of age; after 82 days the chicks lost mass prior to attaining fledging age (97 days). Daily relative growth decreased with age. Food intake increased to 70 days and thereafter decreased. Guano production increased to SO days. Relative food intake decreased with age. Energy content of guano and assimilation efficiency showed no clear changes with age. Mass recession prior to fledging may be related to the lack of post-parental care. Hand-reared gannets grew at an optimum rate when compared with field growth rates from the literature. Juvenile birds were maintained on a diet forming 12,4% of body mass at an assimilation efficiency of 74,2%. Aviary-existence maintenance was 2,4 times standard metabolic rate. The cost of free living in an adult gannet is roughly estimated to be 4,5 X SMR, corresponding to a food intake of 20% of body mass.     

Malignant melanoma of the pelvis as a possible cause of pelvic limb lameness in two gray mares

Two grey mares, a 12-year-old Arabian and a 13-year-old Lippizaner cross, were referred for chronic pelvic limb lameness and abduction of the limb during the non supporting phase of the stride. The clinical examination revealed melanomas under the tail and on the perineum, and oedema of the proximal lame limb. A mass in the pelvic area was detected on rectal palpation. Laparoscopy was performed and the provisional diagnosis of malignant melanoma was made. Histological examination of the biopsy taken under laparoscopic control from the mass in the pelvis confirmed the diagnosis of malignant melanoma. In the postmortem examination a large black mass in the pelvis and metastases in several organs were diagnosed. The process under the tail showed microscopically the characteristics of dermal melanomatosis. The metastases showed the appearance of a malignant melanoma. The lameness and abduction during the non supporting phase of the stride were possibly caused by a combination of pain, a mechanical limitation, and paresis/paralysis. When an older grey horse with melanomas on the predilection sites is submitted with pelvic limb lameness and abduction of the limb during the non supporting phase of the stride, a malignant melanoma in the pelvis is one of the differential diagnoses and a rectal examination should be performed. Diagnostic laparoscopy in the standing horse can be useful to confirm the provisional diagnosis.     

Immunological characterization of the major outer membrane protein of Haemophilus somnus

Antigens and molecular mass diversity of the Haemophilus somnus major outer membrane protein (MOMP) were investigated. The molecular mass of the MOMP of 53 strains of H. somnus varied from 43 to 33 kDa and four MOMP MAb reactivity patterns were detected in immunoblot analysis and immunodot assay. The molecular mass and MAb reactivity data were used for preliminary grouping of H. somnus strains. Disease strains fell into groups 1 and 3, including two of three Group 3 subgroups, whereas strains from asymptomatic carriers were found in all the four groups and three subgroups. Immunoblot analysis with convalescent phase serum showed strain specific reactivity with MOMPs from three isolates used to reproduce disease in cattle. The reaction with the MOMP was only detectable at dilutions of 1:100 or less, whereas the same convalescent sera showed strong reactivity at dilutions of 1:1000 (or more) with other H. somnus antigens. The data suggest that the bovine immune response to the MOMP during infection is weak and is directed to antigenically variable determinants in a strain-specific manner. This may be important in evaluating the role of the antibody response to MOMPs in protective immunity.     

Intraocular melanoma in a horse.

Sudden unilateral blindness occurred in a 7-year-old grey gelding Quarterhorse. Ophthalmoscopy revealed a pigmented mass arising from the nasal ciliary body of the right eye and extending around the posterior surface of the lens, and there were pigmented particles in the vitreous. Examination of the enucleated globe showed a circumscribed, black, dense and symmetrically ovoid mass with sessile attachment to the nasal ciliary region and extension to posterior lens capsule, vitreous and along the vitreal face of the detached retina to the optic papilla. The mass was composed of heavily pigmented, plump, polyhedral cells that invaded the vitreous and the inner limiting membrane of peripapillary retina and optic papilla. It was considered to be a primary, malignant, intraocular melanoma arising from a large uveal nevus.     

Urethral transitional cell carcinoma in a cat

A 15-year-old, male neutered cat was referred for investigation of dysuria. A retrograde urethrography was performed which showed two space-occupying masses within the lumen of the mid-to-proximal urethra. Exploratory coeliotomy revealed two urethral masses. Segmental urethrectomy was performed to resect the mass, and the lower urinary tract was reconstructed by vesico-urethral anastomosis. Histopathology showed the mass to be a transitional cell carcinoma with incomplete surgical margins. Tumour regrowth was suspected when dysuria was found approximately 318 days after surgery. Clinical signs were palliated by radiation using weekly fractions of 6 Gy for three weeks. The cat died of unknown causes 386 days postoperatively.     

Cerebellar myxoid type meningioma in a Shih Tzu dog

A 6-year and 9 month-old, male, Shih Tzu dog showed ataxia and trembling. By MRI examination, a mass (1 cm) was found in the right cerebellum. As the dog did not respond to radiation therapy, and showed a rise of intracranial pressure, he was euthanized. The cerebellar mass was soft and hemorrhagic. Histologically, the mass contained vimentin-positive spindle- or polyhedral-shaped cells arranged in a cord-like pattern. Mucinous materials were observed in the intercellular spaces. Ultrastructural examination revealed cell processes, microtubule-like structures and desmosomes. The case was diagnosed as myxoid type meningioma.     

Malignant mediastinal extra-adrenal paraganglioma with spinal cord invasion in a dog.

A 1.5-year-old castrated, male, mixed-breed dog was evaluated because of a 2-week history of lethargy, stiffness, and progressive paraparesis. Spinal radiographs, myelography, and computed tomography of the region showed a locally invasive mass involving the thoracic wall. Upon necropsy, an encapsulated, fluctuant mass was noted attached to the right dorsal body wall in the region of the fifth to seventh thoracic vertebra. Churukian-Schenk staining revealed positive granules within the neoplastic cell cytoplasm and immunohistochemistry was positive for expression for cytoplasmic neuron-specific enolase and synaptophysin. Chromogranin A and S100 expression were found to be negative. Immunohistochemistry and silver staining did not allow further differentiation of the tumor, and the diagnosis remains consistent with either a chromaffin paraganglioma or a nonchromaffin paraganglioma (chemodectoma) with some production of catecholamines. Extra-adrenal paragangliomas are rare neoplasms in dogs but should be considered as a possible differential diagnosis for a primary paraspinal thoracic mass.