A phaeochromocytoma in a Lhasa Apso dog

This report describes a case of phaeochromocytoma in an intact male Lhasa Apso dog of nearly 10 years old. The dog was suffering from acute lethargy and vomiting. After a successfully performed surgery and concurrent medication, to restore a temporary Addison s disease, the dog is doing clinically well six months later without any remaining symptoms.     

Primary lymphoma of the uterine horn in a Lhasa Apso dog

Primary lymphomas of the canine female genital tract are uncommon tumours. A 9-year-old intact female Lhasa Apso dog presenting with a closed pyometra underwent an ovariohysterectomy (OHE), and the hyperplastic uterine horn along with multiple follicular cysts on the right ovary was examined by histological analysis. Severe infiltration of medium-sized lymphocytes with strong positive immunoreactivity for CD79a and numerous anaplastic features was detected in the unilateral uterine horn, and the dog was diagnosed as having extranodal marginal zone B-cell lymphoma (MZBCL). The present case reports an extremely rare occurrence of primary lymphoma involving the uterine horn in a dog and describes histological characteristics of the tumour for definite diagnosis.     

Colorectal hamartomatous polyposis and ganglioneuromatosis in a dog

A 5-month-old female Great Dane puppy was treated for hematochezia, tenesmus, and rectal prolapse by resection of a 10-cm-long segment of colon and rectum. Grossly, the colorectal segment had diffuse mucosal and submucosal thickening with multiple polypoid nodules. The histologic diagnosis was colorectal hamartomatous polyps with ganglioneuromatosis. Duplication of PTEN was detected by quantitative multiplex polymerase chain reaction testing. The presence of 2 hamartomatous colorectal lesions with PTEN mutation is similar to human Cowden syndrome.     

Small intestinal ganglioneuromatosis in a dog

A 6-week-old Staffordshire Bull Terrier cross was presented with a 4-week history of vomiting and small bowel diarrhoea. Abdominal ultrasound showed thickening of the distal jejunum and ileum. The dog underwent two exploratory laparotomies, during which grossly abnormal sections of intestine were resected. The patient developed septic peritonitis 48 h after the second surgery, caused by dehiscence of an intestinal anastomosis, and was euthanased. All intestinal tissue samples were examined histopathologically and a diagnosis of gastrointestinal ganglioneuromatosis was made. Intestinal ganglioneuromatosis is rare and this case represents a novel occurrence in the small intestine of a dog.     

Mandibular fracture in a Lhasa Apso with secondary renal hyperparathyroidism

A Lhassa Apso is presented in emergency after having been injured by another dog. It was suffering from a mandibular fracture. The clinical exam revealed generalized and excessive mobility of the whole dentition. Radiographs showed generalized jaw bone demineralisation. A blood sample was analysed and revealed chronic renal disease. We came to the conclusion that this dog was suffering from secondary renal hyperparathyroidism. The hypocalcified bone was so thin that a slight trauma induced the mandibular fracture.     

Canine conjoined twinning: A pathoanatomical study of a Lhasa Apso symmetrical cephalothoracopagus

A female pair of conjoined twins of the Lhasa Apso canine breed was subjected to tomographic and anatomical examinations. The twins had only one head and neck. The two ribcages were joined, extending to the umbilicus, with duplicated structures thereafter. They had three thoracic limbs and two pelvic girdles with four limbs, as well as a number of abnormalities in their internal organs. The data obtained were compared with the rare canine cases reported so far and with human cases.     

A spermatozoal midpiece abnormality associated with infertility in a Llasa Apso dog

The semen of a 9-year-old Llasa Apso dog with a recent history of infertility was examined by light and electron microscopy. The presenting sperm abnormality was a high percentage (87 per cent) of cells with proximal cytoplasmic droplets. With the higher resolution of differential interference contrast microscopy and with transmission electron microscopy (TEM) it was apparent that not all of the midpiece abnormalities had the appearance of typical cytoplasmic droplets. Furthermore, by TEM both axonemal and mitochondrial defects were readily demonstrated, often with evidence of degenerative mitochondria in cytoplasmic swellings at other levels of the midpiece. These severe abnormalities were apparent only by TEM of thin sections, although scanning EM was useful in identifying abnormal midpiece outlines. It is suggested that the failure of droplet migration and the midpiece ultrastructural defects were linked to a common fault in spermateliosis.     

Phenotypic intersex (female pseudohermaphroditism) in a dachshund dog

A male miniature rough-haired dachshund, presented with episodic haematuria, was found to be a female pseudohermaphrodite. A littermate also had an abnormality of the urogenital tract and their dam had received a progesterone implant during pregnancy. Chromosome analysis of the intersex revealed XX/XY mosaicism in certain tissues.     

Colorectal basidiobolomycosis in a dog

A 7-year-old castrated male French Bulldog was examined for chronic large intestinal enteropathy. A colonic mass and thickened rectal mucosa were identified, and histopathologic examination of endoscopic biopsy specimens disclosed eosinophilic proctitis with large (5-20 μm), irregularly shaped, pauciseptate hyphae that were Gomori methenamine silver and periodic acid-Schiff positive. Amplification and sequencing of ribosomal DNA extracted from paraffin-embedded tissues yielded a sequence with 97% identity to GenBank sequences for Basidiobolus ranarum. After itraconazole, terbinafine, and prednisone administration, clinical signs resolved rapidly, and sonographic lesions were largely absent after 6 weeks. Treatment was discontinued by the owner 15 weeks after diagnosis. Three weeks later, the dog collapsed acutely and was euthanized. Necropsy identified metastatic islet cell carcinoma and grossly unremarkable colorectal tissues. However, histopathology of the rectum disclosed multifocal submucosal granulomas with intralesional hyphae morphologically similar to those previously observed. This report is the first to describe medical treatment of gastrointestinal basidiobolomycosis in a dog.     

Multiloculated solitary (unicameral) bone cyst in a young dog

A 20‐month‐old female spayed Staffordshire Terrier (22.3 kg) presented to the Orthopedic Surgery Service at North Carolina State University Veterinary Teaching Hospital for evaluation of a 6‐week history of toe‐touching to nonweight‐bearing lameness in the right hind limb. Radiographs of the right stifle revealed a multiloculated lytic lesion of the distal femur, with a large open lytic zone centrally, numerous osseous septations peripherally, and focal areas of cortical thinning and loss. An aspirate of the right distal femoral lesion yielded mildly cloudy serosanguineous fluid. Cytologic examination of the fluid revealed a pleomorphic population of discrete cells that exhibited marked anisocytosis and anisokaryosis and a variable nuclear‐to‐cytoplasmic (N:C) ratio, which were interpreted as probable neoplastic cells, with few macrophages, and evidence of hemorrhage. Given the clinical signs of pain, lesion size, and concern for malignant neoplasia, amputation of the right hind limb was performed. Histologically, the lesion had undulating walls 1‐3 mm thick with a continuous outer layer of dense fibrous tissue and an inner layer composed of reactive cancellous bone with no cortical compacta remaining. Remnants of thin fibrous or fibro‐osseous septa projected from the bony wall into the cyst lumen. The final histologic diagnosis was a benign multiloculated solitary (unicameral) bone cyst of the distal right femur. Based on the histopathologic findings, it was speculated that the cells identified on cytology were a mixture of developing osteoclasts, osteoblasts, endothelial, and stromal cells. This is the first report describing the cytologic examination of a solitary bone cyst in veterinary medicine.     

Hemophilia A in a female dog

Hemophilia A was diagnosed in a mixed-breed female dog with an acute bleeding disorder. Coagulation factor analysis was used to determine low factor VII-coagulant activity in the dog. Hemophilia A is an X chromosome-linked recessive trait that has not been reported as a cause of disease in female dogs.     

Colonic ganglioneuromatosis in a horse

Ganglioneuromas are complex tumors that arise in peripheral ganglia and are composed of well-differentiated neurons, nerve processes, Schwann cells, and enteric glial cells. The term ganglioneuromatosis (GN) denotes a regional or segmental proliferation of ganglioneuromatous tissue. This report describes an 8-year-old mixed breed horse with GN in a 25-cm segment of small colon. Grossly, the lesion consisted of numerous sessile to pedunculated nodules extending from the serosal surface. Histologic examination revealed the nodules to consist of fascicles of spindle-shaped cells consistent with Schwann cells, clusters of neurons, supporting enteric glial cells, and thick bands of perineurial collagen. Most of the nodules coincided with the location of the myenteric plexus and extended through the outer layer of the tunica muscularis to the serosal surface. Neuronal processes were demonstrated within the lesion with electron microscopy. With immunohistochemistry neurons were positive for neuron specific enolase (NSE) and S-100 and the Schwann cells and enteric glial cells were positive for S-100 and glial fibrillary acidic protein (GFAP). The pathogenesis of GN is poorly understood. GN, although rare, should be included in the differential diagnosis of gastrointestinal tumors in the horse.     

Cutaneous angiomatosis in a young dog

A 1-year-old, spayed, female, mixed-breed dog had two reddish-purple cutaneous lesions, one on the right dorsal antebrachium and the other on the right shoulder. The lesions consisted of approximately 13 x 3 cm and 15 x 10 cm, irregular, patchy regions of 0.5-3.0 cm, circular, sometimes raised, reddish-purple swellings resembling ecchymoses. The lesion on the antebrachium had been noticed since the dog was adopted at 6 months of age and appeared to have increased in size over an 11-week period, at which time skin punch biopsy revealed an infiltrative pattern of well-differentiated blood vessels leading to an interpretation that the lesion was a well-differentiated hemangiosarcoma. The second lesion was revealed when the dog had its fur shaved in that area during surgical preparation to excise the antebrachial lesion. No other skin lesions were found on the dog. Microscopically, there was a widely disseminated and infiltrative-like pattern of benign-appearing small blood vessels, which were throughout the superficial and deep dermis and subcutis. Although the disseminated nature suggested malignancy, the histologic appearance of well-differentiated small blood vessels and nonprogressive clinical features indicate that the lesions were benign. The dog has been followed for 6 years and to date has no evidence of progression of the antebrachial lesion or shoulder lesion. To the authors' knowledge, this is the first report of a congenital angiomatosis-like lesion in a young dog, with extensive involvement of the forelimb.     

Hepatic lymphangiomatosis in a young dog

A 9-month-old intact male American cocker spaniel was referred because of hepatomegaly and ascites. Ultrasonographic evaluation of the liver revealed congestion and increased parenchymal echogenicity with focal and more hyperechoic nodules. Histopathology of the hepatic lesion revealed diffuse, ill-defined vascular proliferation. A single layer of endothelial cells, which showed signs of minimal cellular atypia, lined the irregular vessels. On immunohistochemistry, the proliferative endothelial cells lining the irregular vessels were positive for an antiserum to factor VIII related antigen. Based on these findings, the dog was diagnosed with hepatic lymphangiomatosis.     

Gastroduodenal intussusception in a young dog

A 21-month-old German shepherd crossbreed presented with a nine-month history of intermittent vomiting, anorexia and melaena interspersed with periods of clinical normality. Investigations suggested recurrent pancreatitis and the vomiting resolved with supportive therapy but recurred two weeks later. Abdominal radiographs revealed evidence of an intermittent abdominal mass which, on uitrasonography, had the typical appearance of an intussusception. At laparotomy, a gastroduodenal intussusception was found obstructing the pancreatic and bile duct outflows with perforation of the duodenal wail. The dog was euthanased. Postmortem examination and histology showed no obvious cause for the intussusception but confirmed pancreatic involvement. This is believed to be the first case of gastroduodenal intussusception reported in an animal.     

Essential hypernatraemia in a young dog

A five-month-old great dane puppy was presented with hypernatraemia and clinical signs of vomiting, depression, disorientation, hyperi-rritability and adipsia. A diagnosis of essential hypernatraemia was based on the observation of adipsia, severe hypernatraemia, ability to concentrate urine only when hypovolaemic, normal serum aldosterone levels, normokalaemia and normotension. No abnormalities were found on histopathology of the neurocircuitry of the brain. This dog is compared with other reported cases of hypernatraemia in both dogs and humans.     

Hepatocellular carcinoma in a young dog

A 25-month-old Chihuahua dog with no clinical signs was evaluated for high serum liver enzymes. Ultrasonography and computed tomography revealed a mass in the left hepatic medial lobe. The histological diagnosis reached using resected tissues was hepatocellular carcinoma (HCC). To the authors’ knowledge, this is the youngest dog diagnosed with HCC.