Ventricular ependymoma in a German Shepherd dog

Using magnetic resonance imaging (MRI) together with clinical, pathomorphological and immunohistological methods, a ependymoma is described in a 9-year-old German Shepherd dog, which presented with behavioural and oculocephalic responses and generalised ataxia. The ependymoma, 9 x 6 x 5mm in size, was localised intra-axially in the right interventricular foramen and hydrocephalus was observed by MRI. Microscopically, the tumour was composed of pseudorosettes, and immunohistochemical examination revealed vimentin and glial fibrillary acidic protein immunoreactivity in the neoplastic cells.     

Primary cardiac fibrosarcoma with pulmonary metastasis in a Labrador Retriever

A 6-year-old, neutered male Labrador Retriever was diagnosed with congestive heart failure, and an echocardiogram revealed a large mass inside the pericardial sac associated with the left ventricle. At necropsy, the dog had marked ascites, mild hydrothorax, marked hydropericardium, and an 11.0 x 7.0 x 6.0 cm, tan and red, firm, well-demarcated mass attached to the left ventricular free wall. The mass was diagnosed as a fibrosarcoma based on the morphologic appearance and supportive immunohistochemical staining. To our knowledge, this is the first case report of a primary fibrosarcoma involving the left ventricular free wall myocardium, epicardium, and pericardium with a pulmonary metastasis in a dog.     

IMAGING DIAGNOSIS — MAGNETIC RESONANCE IMAGING OF INTRACRANIAL INFLAMMATORY FIBROSARCOMA IN A MIXED BREED DOG

An 8‐year‐old mixed‐breed dog presented with progressive behavioral changes and altered mentation. Magnetic resonance imaging (MRI) of the brain revealed an olfactory and frontal lobe extra‐axial mass. The mass exhibited the following MRI signal intensity characteristics: T2W mixed, T1W iso‐ to hypointense, FLAIR hyperintense, and strong contrast enhancement. The mass was removed with cavitronic ultrasonic surgical aspirator (CUSA) assisted neurosurgery. Based on histopathological appearance and immunohistochemistry, the diagnosis of inflammatory fibrosarcoma was made. To our knowledge, this is the first report describing MRI characteristics of intracranial inflammatory fibrosarcoma in the veterinary literature.     

Bilateral Iliopsoas Muscle Contracture and Spinous Process Impingement in a German Shepherd Dog

Objective— To report diagnosis and treatment of bilateral iliopsoas muscle contracture in a dog with spinous process impingement. Study design— Case report. Animals— German Shepherd dog. Methods— A dog with chronic progressive lameness, flexion contracture of the coxofemoral joints, severe pain, and decreased femoral reflexes had severe spondylosis bridging the vertebral bodies from L1 to L4 and enlarged dorsal spinous processes from T8 to L6 with impingement and bony proliferation. Ultrasonographic and magnetic resonance imaging (MRI) findings were consistent with fibrosis, mineralization, and atrophy of the iliopsoas muscles bilaterally which was treated by staged tenectomy of the insertions of the iliopsoas muscles. Results— Because of severe perivascular fibrosis, the femoral vessels required ligation. Bilateral iliopsoas muscle tenectomy improved gait and provided pain relief. Histologic findings were consistent with fibrotic myopathy. Conclusions— Slow progression of severe clinical signs observed bilaterally in this dog differs from previous reports of iliopsoas myopathy. Findings were similar to the fibrotic myopathy of the gracilis or semitendinosus muscles described in dogs. Clinical Relevance— Iliopsoas muscle abnormalities should be considered in dogs with limited hip extension and pain. MRI is useful for diagnosing muscle fibrosis. Iliopsoas tenectomy may improve clinical function in dogs with fibrotic myopathy.     

Vincristine sulfate as single-agent chemotherapy in a dog and a cat with malignant neoplasms

A 12-year-old 4-kg spayed domestic shorthair cat with a poorly differentiated fibrosarcoma of the rostral aspect of the mandible and an 11-year-old 13-kg castrated dog of mixed breeding with pulmonary metastatic hemangiosarcoma were treated with 0.5 mg of vincristine sulfate/m2 of body surface, IV, weekly. Three months after beginning treatment, both animals had complete clinical remission. The role of this vinca alkaloid as a single agent for malignant neoplasms has seldom been discussed in the veterinary scientific literature. The results of these two cases indicate that single-agent vincristine sulfate chemotherapy is effective in the treatment of feline fibrosarcoma and canine hemangiosarcoma.     

Disseminated Scedosporium prolificans infection in a German Shepherd dog

Disseminated Scedosporium prolificans infection in a 1-year-old female spayed German Shepherd dog is described. Clinical signs were predominantly associated with fungal pyelonephritis and the organism was cultured from the urine. The dog was treated with itraconazole and later, terbinafine was added. Subsequent antifungal susceptibility testing of the isolate showed it to be resistant to all available antifungal drugs. The dog was euthanased because of acute abdominal haemorrhage and associated clinical deterioration. Postmortem examination revealed extensive pyogranulomas containing fungal organisms in the renal parenchyma, myocardium, bone marrow, skeletal muscle, liver, lung, spleen, multiple lymph nodes and pancreas.     

Predatory aggression in a German shepherd dog

This article presents a clinical case of predatory aggression that represents a problem for public health. The patient was a 2-year-old male German shepherd referred to the behavior clinic at the School of Veterinary Medicine owing to its aggressive behavior toward people and other dogs. The dog tended to form a pack with the other dogs of the household and killed neighborhood dogs, cats, hens, and rabbits. The presumptive diagnosis was “predatory aggression” associated with “territorial and protective aggression.” The risk analysis determined that the dog should be euthanized. Nevertheless, the owner refused, and hence behavior modification and drug therapy were recommended. A year later, the dog killed again (another dog), indicating that despite the drug and behavioral treatment, it is likely that its predatory aggression will never be resolved.     

Surgical and radiotherapy treatment of a spinal cord ependymoma in a dog

A 4-year-old Beagle dog was presented for investigation of a left pelvic limb gait abnormality. Neurolocalisation indicated a lumbar (L2 to L5) spinal cord lesion. On magnetic resonance imaging (MRI), an intramedullary mass was demonstrated at L3. The mass was partially removed under general anaesthesia and a diagnosis of ependymoma was made on histological examination. The dog was treated with postoperative orthovoltage x-ray radiation (total dose; 44 Gy given in 11 fractions over a 4 week period) combined with low dose carboplatin (25 mg/m2). The dog was alive 16 months after surgery without further neurological deficits. No further tumour growth was detected on subsequent MRI evaluations.     

Sartorius muscle contracture in a German shepherd dog

Objective— To report sartorius muscle contracture in a dog.
Study Design— Case report.
Animals— A 5-year-old, male, German Shepherd dog.
Methods— After a 2-month history of right hindlimb lameness was treated by tenectomy of the caudal sartorius muscle for sartorius muscle contracture.
Results— One month after surgery there was complete remission of clinical signs; however, after 12 months, there was partial reunion of sartorius caudal belly and onset of gracilis muscle contracture.
Conclusions— Contracture of the sartorius muscle in dogs is seemingly rare and similar to gracilis muscle contracture with which it may be confused. Differentiation requires knowledge of muscular anatomy, careful palpation, and surgical inspection.
Clinical Relevance— Sartorius muscle contracture can be treated by tenectomy or removal of contracted muscle tissue, however, long-term outcome suggests the need to develop approaches that prevent recurrence caused by scarring of transected tissues.     

Tumor-Associated Erythrocytosis in a Dog With Nasal Fibrosarcoma

Erythrocytosis (hematocrit, 79%) was diagnosed in an 8-year-old, neutered female, mixed-breed dog with an intranasal fibrosarcoma. Both serum and tumor erythropoietin (Ep) activities were elevated, as determined by the polycythemic exhypoxic mouse model, and the Ep activity was neutralized in that model by rabbit anti-Ep antibodies. Tumor resection normalized the hematocrit.     

PROBABLE TRIGEMINAL NERVE SCHWANNOMA IN A DOG

A 7-year-old male Husky dog developed atrophy of the right masseter muscle and pruritis of the right side of the face. A myogenic origin was excluded using muscular biopsy. Electrophysiologically, there was involvement of the motor and sensory fibers of the trigeminal nerve, suggesting a lesion located between the brainstem and the trigeminal ganglion. On MRI examination, a nodular mass was detected in the right caudal fossa. This mass was characterized by intense enhancement after injection of contrast medium. Because of the progressive clinical signs, electrophysiology, and MRI results, a presumptive diagnosis of a trigeminal nerve schwannoma was made. The animal's condition improved slightly with corticosteroids. The dog underwent euthanasia 3 months after initial presentation. Necropsy was not performed.     

Polycythemia associated with renal fibrosarcoma in a dog

A 10-year-old Beagle-type dog with intermittent vomiting and anorexia had an absolute polycythemic condition. A renal mass was detected and removed by total nephrectomy. After surgery, the hematologic values returned to normal, suggesting that the tumor was the cause of the polycythemia. The histologic diagnosis was fibrosarcoma. In dogs, secondary polycythemia has otherwise been reported with renal carcinoma and lymphosarcoma.     

Papillary ovarian cystadenocarcinoma in a dog

An 11-year-old female German Shepherd dog was presented for investigation of progressive enlargement of the abdomen, periodic bloody discharge from the vulva and rapid exhaustion. Transabdominal ultrasonography and lateral abdominal radiography demonstrated an echogenic formation with anechogenic cavities located cranial to the urinary bladder and a homogeneous shadow with an elliptical shape was located caudal to the rib arc. Both showed indistinct borders. Exploratory laparotomy identified bilateral ovarian masses and ovariohysterectomy was performed. Histopathology confirmed ovarian cystadenocarcinoma. The dog remained clinically normal without evidence of metastatic disease 4 months after surgery. Papillary cystadenocarcinoma in the bitch could affect both ovaries and manifests with a rapid growth rate and clinical signs such as rapid exhaustion, abdominal enlargement and vulval discharge. Ovariohysterectomy is the treatment option.     

Malignant anterior uveal melanoma with diffuse metastasis in a dog.

Enucleation was performed in 10-year-old sexually intact female mixed-breed German Shepherd Dog. Histologic examination revealed that the dog had an uveal amelanotic melanoma of the eye. The tumor consisted of anaplastic cells with a high mitotic index, indicating malignancy. On examination 3 months after enucleation, the dog had difficulty breathing and nasal discharge. Radiography revealed pulmonary metastasis. The dog was euthanatized. Necropsy revealed diffuse metastasis involving various organs.     

Immunohistopathologic characterization of a dermal melanocytoma-acanthoma in a German Shepherd Dog

A cutaneous melanocytoma-acanthoma in a 2-year-old female German Shepherd Dog was characterized by the presence of two populations of neoplastic cells: epithelial and melanocytic. The epithelial component consisted of nests of well-differentiated stratified squamous epithelium closely associated with neoplastic melanocytes. The epithelial cells immunoreacted with both monoclonal and polyclonal anti-cytokeratin antibodies, and immunoreaction to S-100 protein and vimentin was observed in the melanocytic cells. This rare pigmented skin neoplasm of the dog apparently has a benign behavior.     

Food intake and growth of German shepherd puppies

The nutritional programme followed during the growth and development of the German shepherd puppy may have a significant influence on the dog's value as a potential working or breeding animal. Limited research has been undertaken on the nutrition of the dog from birth until four to five weeks of age. The objective of this study was to establish a baseline in terms of food intake and growth, which can be used in a nutritional and managerial programme in a commercial breeding unit. The food intake and growth of 10 German shepherd dog litters, with an average of six puppies per litter, were monitored from birth to 12 weeks of age. Both food intake and growth was described by regression equations. A commercially available diet was fed throughout the study. Performance criteria, namely food intake and bodyweight, were established which could be used in a commercial German shepherd dog breeding unit.     

Fibrosarcoma with typical features of postinjection sarcoma at site of microchip implant in a dog: histologic and immunohistochemical study

A 9-year-old, male French Bulldog was examined for a subcutaneous mass located at the site of a microchip implant. Cytologic examination of the mass was suggestive of a malignant mesenchymal neoplasm. Histologically, the mass was confirmed as a high-grade infiltrative fibrosarcoma, with multifocal necrosis and peripheral lymphoid aggregates. By immunohistochemistry, the sample was investigated for vimentin, smooth-muscle actin (SMA), CD3, CD79alpha, and CD18. All the neoplastic cells were positive for vimentin. Scattered cells at the periphery of the lesion were also positive for SMA, highlighting a myofibroblastic phenotype. The lymphoid cells were positive for CD18 and CD3. No aluminum deposits were detected by the aurintricarboxylic acid method. A diagnosis of fibrosarcoma morphologically similar to feline postinjection sarcomas was made. Fibrosarcomas at the site of injections have been reported in dogs and ferrets. Furthermore, neoplastic growth at the site of microchip implant in dog and laboratory rodents has been described.     

Discospondylitis in association with an intra-abdominal abscess in a dog

An 11-year-old German shepherd dog cross was presented with a six-week history of weight loss and abdominal distension. A diagnosis of abdominal abscess and discospondylitis was made. The dog responded to surgical excision of the abscess and conservative medical treatment for discospondylitis.     

Retropharyngeal fibrosarcoma in a dog

A 2½-year-old Alsatian dog was admitted to the University of Liverpool Field Station as a respiratory emergency after dysphagia had been observed for 6 weeks. During surgery a fibrosarcoma was found in the connective tissue of the posterior pharyngeal region. The clinical, radiological, surgical and post-mortem features are described.     

Cytologic appearance of a keloidal fibrosarcoma in a dog

A 5-year-old neutered male, mixed-breed dog was presented with a single 4-mm, nodular, firm, haired subcutaneous mass on the left flank that had been present for approximately 2 weeks. Cytologic preparations of the mass revealed many spindle cells, few mast cells, rare eosinophils, rare macrophages, abundant hyalinized collagen, and moderate numbers of erythrocytes. The spindle cells were oval to fusiform, with oval nuclei, finely stippled to lacy chromatin, 1-5 variably sized prominent nucleoli, and moderate to abundant cytoplasm with indistinct cell borders, wispy cytoplasmic extensions, and occasionally, fine magenta granulation. The cell population exhibited moderate anisocytosis, moderate anisokaryosis, and rare binucleation. The eosinophilic material occurred both in large angular aggregates with blunt ends and in amorphous aggregates with fine wispy projections. Histologic findings were consistent with a keloidal fibrosarcoma. To the authors' knowledge, this report is the first to describe the cytomorphologic characteristics of a keloidal fibrosarcoma in a dog.