PRIMARY OSTEOSARCOMA OF THE STERNUM OF A DOG

Primary osteosarcoma of the fifth sternebra is reported in a 6-year-old male Great Dane. Presenting signs were suggestive of myocarditis and pulmonary congestion. Electrocardiography revealed R waves of low and variable amplitude and the plasma alpha-hydroxibutyrate dehydrogenase level was elevated. Radiography revealed neoplasia of the fifth sternebra with extensive bilaterial pulmonary metastases. Histologically the neoplasm showed typical osteosarcoma with plentiful osteoid production.     

Diagnosis, treatment and outcome of orbital neoplasia in dogs: a retrospective study of 44 cases

Forty-four dogs with confirmed orbital neoplasia were studied. Eighteen tumour types were represented and 95 per cent of the neoplasms were classified as malignant. The tumour types most commonly diagnosed were osteosarcoma, fibrosarcoma and nasal adenocarcinoma. Thirty-six per cent of the dogs had at least one clinical sign that was compatible with a diagnosis of orbital abscessation or cellulitis. Fifty-six per cent of the dogs, where follow-up information was available, were euthanased or had died within six months of diagnosis, while 19 per cent of the total were still alive after one year post-diagnosis. Cytological examination was diagnostic for orbital neoplasia in 49 per cent of the fine needle aspirates of the retrobulbar space. In contrast, 56 per cent of the non-surgical biopsies were diagnostic for orbital neoplasia. Of those dogs that had died or been euthanased within six months of diagnosis, only 22 per cent had undergone some form of therapy for orbital neoplasia. In comparison, 86 per cent of dogs surviving longer than six months post-diagnosis had undergone such therapy.     

Metastatic osteosarcoma tumor thrombus in a Cavalier King Charles Spaniel presenting with dyspnea

A six-year-seven-month-old female neutered Cavalier King Charles Spaniel was referred for the investigation of progressive dyspnea and hyphema in the right eye with secondary glaucoma. Previous medical history included a high-grade soft tissue spindle cell sarcoma removed from the cranial sternal region one year before.On presentation at the referral hospital, the dog was tachypneic and dyspneic. The heart rhythm was regular and there was a soft left-sided systolic murmur. Echocardiography identified the presence of a mass significantly occluding left heart inflow, with no other lesions identified. Thoracic radiographs documented a localized alveolar pattern within the left caudal lung lobe. The size of the heart and pulmonary vessels were within normal limits, indicating a non-cardiogenic alveolar pattern.Given the clinical presentation of dyspnea and high index of suspicion of intra-cardiac neoplasia, the dog was considered to have a grave prognosis and therefore euthanized. Post-mortem gross and histopathologic examination revealed the presence of a metastatic osteosarcoma tumor thrombus in the left atrium and pulmonary vein, metastatic osteosarcoma infiltrating the myocardium, lungs, the uveal tract of the right eye, and both adrenal glands. Whitney grade II myxomatous changes were noted on the mitral and tricuspid valve leaflets.This report describes an unusual intra-cardiac tumor thrombus in a dog presenting with dyspnea. Cavalier King Charles Spaniels presenting with dyspnea often raise suspicion for myxomatous mitral valve disease. However, as demonstrated in this case, other more unusual causes of dyspnea should also be considered in the absence of classic clinical findings.     

Malignant neoplasia in four alpacas.

Malignant neoplasia in 4 alpacas was characterized by acute onset of clinical signs and rapidly deteriorating condition. Postmortem examination revealed metastatic or multicentric neoplasia in the abdominal organs of alpacas 1, 3, and 4 and an extensive thoracic mass in alpaca 2. Immunohistochemical stains supported a diagnosis of B-cell lymphosarcoma in alpacas 1-3 and a neuroendocrine neoplasm in alpaca 4.     

Cor triatriatum sinister in a cat

A heart murmur was detected in a five-month-old Persian chinchilla cat. The animal was referred to Nihon University Animal Medical Center where radiographic examination revealed an enlarged heart with dilation of pulmonary arteries and veins and pulmonary oedema. Echocardiography revealed partition of the left atrium, with turbulent blood flow within the left atrium. The patient was placed under continuous care at the facility, but died at seven months of age. Postmortem examination revealed that the left atrium was partitioned by a fibromuscular septum, with a 1 mm diameter perforation, consistent with a diagnosis of cor triatriatum sinister.     

A sacro‐caudal spinal cord choroid plexus papilloma in a shar‐pei dog

A seven‐year‐old shar‐pei dog was referred because of severe lumbosacral pain and faecal incontinence of 20 days’ duration. Neurological examination was characterised by plegic tail, absence of perineal reflex, dilated anus, perineum and tail analgesia, and severe lumbosacral pain. The neurological clinical signs were suggestive of a selective lesion involving sacral and caudal spinal cord segments and/or related nerve roots. A magnetic resonance imaging of lumbosacral spine was performed and was suggestive of an intradural lesion. Primary or secondary neoplasia was considered as the most probable differential diagnosis. The dog was euthanased upon the owner's request. Histopathological examination confirmed the presence of an intradural‐extramedullary neoplastic tissue enveloping intradural tract of spinal nerve roots. On the basis of histological and immunohistochemical findings, a diagnosis of well‐differentiated choroid plexus papilloma was made. To the authors's knowledge, this is the first case of primary or metastatic spinal choroid plexus papilloma in dogs.     

Pressure Distribution Under Paws of Chinchilla (Chinchilla Laniger)

The purpose of this study was to estimate the pressure distribution under the paws of chinchilla ( Chinchilla laniger ) using static pedobarography. We included in our study three healthy chinchilla aged 1–3 year, both sexes, weighted 480–570 g. We performed static pedobarography (PEL 38 podometer) in each chinchilla and we took into account standing on four legs or two hind legs. We found that on standing on four legs, two types of contact area with base in chinchilla exist: first type – the ring shape of contact area with base of forefeet with maximal pressure in forefeet at their central part and elliptic shape of foot contact area with base of hind legs (paws) with longer diameter about twice longer than the shorter one and with maximal pressure in hind legs at their posterior part (greater than pressure under forefoot paws), that a value was 98 g/cm² In the second type of foot contact area with base a pattern of hind legs was similar to that of forefeet. During standing on two hind legs we distinguished the another type (third) of foot contact area with base that was similar to the first type with the difference made by the fact that animal was standing only on hind paws. In each animal we found also the contact area with base of a tail – the contact area was similar to that of forefeet but the value of pressure was twice decreased. Concluding, the most frequent manner of contact area with base in chinchilla is 4 points contact with hind paws contact area twice greater than contact area of forefeet. Moreover, the fifth point of support can exist – a tail, which is mainly important during standing on the hind paws.     

Taenia coenurus in the orbit of a chinchilla

A 4-year old, male intact, captive-bred chinchilla (Chinchilla lanigera) was presented due to progressive exophthalmos of the right eye over a 5-month period. Ophthalmic examination revealed exophthalmos with dorsal displacement of the right globe. Retropulsion was decreased and a fluctuant, subcutaneous mass could be palpated posterior and dorsal to the central aspect of the zygomatic bone. Transdermal ultrasonography revealed a fluid-filled mass consistent with a cyst located within the ventral right orbit. Computed tomography demonstrated dorsal displacement of the globe, lateral displacement of the zygomatic arch, and numerous mineral-dense foci within the lumen of the cyst. The cyst was removed en bloc by ventral transpalpebral orbitotomy. Histopathology revealed a single capsulated cyst with multiple invaginated protoscolices, characterized by a prominent scolex with refractile hooklets, suckers, and abundant calcareous corpuscles consistent with a Taenia coenurus. Exophthalmos resolved with surgical therapy and there was no evidence of recurrence or postoperative complications over a period of 2 years. To the authors' knowledge, this is the first reported case of an orbital cyst of parasitic origin in a chinchilla.     

UTERINE LEIOMYOMA,FIBROMA, AND HEMANGIOMA IN 2 CHINCHILLAS (CHINCHILLA LANIGER)

Two female chinchillas were presented with reduced appetite and production of small fecal pellets. Physical examination of both chinchillas revealed a reduced vaginal membrane, bloody vaginal discharge, and a palpable mass in the caudal abdomen. Radiographic images revealed soft tissue masses in the caudal abdomen of both animals. In addition, the first case was examined by ultrasound, which identified 2 cystic masses, each originating from 1 of the uteri. Both chinchillas were euthanized due to progressive clinical deterioration with both animals undergoing postmortem examinations. Grossly the uterine masses were confirmed, in the first case adhering to the jejunum and mesojejunum and in the second case leading to compression of the rectum in the pelvic cavity. Histopathological examination and immunohistochemical staining of the masses were consistent with presence of uterine leiomyoma and fibroma in the first case and a uterine hemangioma in the second case. The bloody vaginal discharge was assumed to be caused by the fibroma with multifocal acute hemorrhages and rupture of the hemangioma, respectively. The presented cases intend to increase the knowledge base of chinchilla oncology.     

Evaluation of brush cytology in the diagnosis of chronic intranasal disease in cats

Brush cytology was used as a diagnostic aid in 85 cats affected with chronic intranasal disease. Fifty-three of these cases, sampled over a five-year period, were included in this study, while the other cases were excluded due to poor cellularity of the cytological samples (nine cases) or a lack of histological or follow-up data (23 cases). Thirty-six brush samples were classified by cytology as inflammatory. Subsequent histological examination revealed a false negative diagnosis of neoplasia in six cats, two of which had malignant tumours (one adenocarcinoma and one lymphoma), the remaining four having benign tumours (two adenomas and two osteochondromas). Seventeen samples were classified by brush cytology as neoplastic. This was confirmed in 16 of these cases by histology or follow-up (nine epithelial malignant tumours, six lymphomas and one osteosarcoma). In the remaining case, a false positive diagnosis of lymphoma was made. The procedure had an overall 86.8 per cent (46/53) agreement between the diagnosis of inflammatory conditions versus neoplasia, with a sensitivity of 72.7 per cent, a specificity of 96.8 per cent, a predictive value of a positive test of 94.1 per cent and a predictive value of a negative test of 83.3 per cent.     

An atypical lymphoma of T-cell lineage in the thorax of an aged cow.

An aged beef cow was presented for signs of thoracic disease. A complete clinical and diagnostic workup suggested neoplasia. Postmortem examination revealed a lymphoma of T-cell lineage confined solely to the thoracic cavity, predominantly in lung tissue. The diagnosis was based on light and electron microscopy, immunohistochemistry, and negative bovine leukemia virus and bovine immunodeficiency virus results.     

Solitary plasmacytoma of bone in two successfully treated cats

This is the first report of feline solitary plasmacytoma of bone. We describe the clinical, clinico-pathological, radiographic and pathological findings of two successfully treated cats with long-term follow-up. The first case presented with spinal pain and neurological deficits. Radiographs demonstrated sclerosis of lumbar vertebra L6 and a myelogram confirmed interference to flow of contrast in the L4-7 region. A biopsy of L6 revealed neoplastic plasma cell infiltration. There was no evidence of paraproteinaemia on serum protein electrophoresis. The cat underwent hypofractionated megavoltage radiotherapy. Clinical signs resolved completely and 4 years after diagnosis the cat remains well and has no electrophoretically detectable paraproteinaemia. The second case presented with neurological deficits of the tail and spinal radiographs revealed extensive osteolysis of the sacrum. A biopsy of sacral bone demonstrated neoplastic plasma cell infiltration. The animal was normoglobulinaemic. The cat improved clinically with induction chemotherapy (melphalan and methylprednisolone). The same chemotherapeutics were continued at maintenance doses for 4.3 years, at which time there was recurrence of neurological deficits and a palpable sacral mass. Cytological examination of a fine needle aspirate confirmed recurrence of plasma cell neoplasia. A low concentration monoclonal paraproteinaemia was detected. Vincristine was administered resulting in resolution of neurological deficits and a palpably smaller sacral mass. Eighteen months into vincristine therapy, there was recurrence of clinical signs and the cat was euthanased, more than 6 years after the initial diagnosis.     

Stress-induced Cushing's syndrome in fur-chewing chinchillas

One of the most serious problems in the chinchilla industry is 'fur-chewing', when the chinchilla bites off areas of its own or some other animal's fur. The condition generally develops in both genders at the age of 6-8 months. In chinchilla farms in Croatia an incidence of 15-20% has been observed. A pathomorphological, microbiological and parasitological investigation was conducted on eleven 6- to 11-month-old chinchillas of both sexes with clinical symptoms of 'fur-chewing' and three chinchillas without such signs. Histopathology of the adrenal glands and of the chewed skin revealed changes typical of Cushing's syndrome in 'fur-chewed' chinchillas, such as hyperkeratinisation of the epidermis, epidermal atrophy, pronounced follicular and sebaceous gland atrophy, hyperkeratinisation of the follicles with comedo formations and the presence of calcium salts in subcutis.     

Primary mesenteric root osteosarcoma in a dog

Abstract: A 10‐year‐old spayed female Boxer‐mix was presented with a history of several weeks of soft stools, straining to defecate, inappetance, and lethargy and several days of hematochezia, melena, and dyschezia. Physical examination findings included mild tachycardia and tense cranial abdomen. CBC results indicated moderate mature neutrophilia. Ultrasonographic examination of the abdomen revealed a large mass with complex echogenicity in the cranial abdomen, likely associated with the intestines. Cytologic examination of a fine‐needle aspirate revealed a population of round, stellate, and spindle‐shaped cells arranged individually and in aggregates with occasional cells embedded in an eosinophilic extracellular matrix. The cytologic interpretation was malignant mesenchymal neoplasm with osteosarcoma being the primary differential. Surgical exploration of the abdomen revealed a 10‐cm‐diameter mass located at the intestinal mesenteric root. The mass occluded blood flow to portions of the gastrointestinal tract. The dog was euthanized due to the nonresectable nature of the tumor. Histopathologic examination revealed an expansile poorly demarcated mesenchymal neoplasm composed predominantly of spindloid and pyriform cells, occasionally embedded in a matrix compatible with osteoid. The diagnosis was extraskeletal osteosarcoma of the intestinal mesenteric root, only rarely reported in dogs.     

Subtotal scapulectomy as the treatment for scapular tumour in the dog: a report of six cases

The medical records of six dogs treated by sub-total scapulectomy for tumours involving the scapula were reviewed. The mean age of dogs in this study was 8 years and 4 months. Clinical signs on presentation included lameness of the affected forelimb and a palpable mass over the scapular area on physical examination. Pre-operative chest and affected forelimb radiographs were taken in most cases in addition to a biopsy. Subtotal scapulectomy was performed, ensuring margins clear of neoplastic tissue of at least 2 cm, preservation of the glenoid cavity and thus retention of the scapulo-humeral joint. On histopathological examination the tumours where diagnosed as chondrosarcoma (one), haemangiosarcoma (two), anaplastic malignant neoplasia (one) and osteosarcoma (one). Limb function was found to be good in all cases postoperatively. Prognosis was related to histopathological diagnosis of the tumour, favourable with chondrosarcoma and poor with the other tumour types.     

Primary ocular osteosarcoma in a dog

An adult male Rottweiler presented to the veterinary medical teaching hospital at Purdue University with a 1-month history of hyphema. On physical examination conjunctivitis, episcleral hyperemia, corneal edema, hyphema, mild glaucoma and loss of vision were observed in the left eye. No other abnormalities were found. The left globe was surgically removed because of the high likelihood of neoplasia and it was fixed in 10% buffered formalin and submitted for pathology. A histologic diagnosis of primary osteosarcoma of the eye was made. Radiographic evaluation did not reveal any evidence of other tumors or pulmonary metastasis. This is the fourth canine case of primary intraocular osteosarcoma to be documented.     

Primary jejunal osteosarcoma associated with a surgical sponge in a dog

Primary jejunal osteosarcoma was diagnosed in association with a surgical sponge in a dog. The tumor was biologically aggressive, resulting in widespread metastasis throughout the abdomen within 2 months of surgical resection. Microscopic examination of the resected osteosarcoma revealed strands of gauze material throughout the tumor mass. It was theorized that the presence of a sponge foreign body may have resulted in malignant transformation of adjacent tissues similar to what has been reported to occur after internal fixation of some long-bone fractures.     

Membranoproliferative glomerulonephritis possibly associated with over-vaccination in a cocker spaniel

Membranoproliferative glomerulonephritis was observed in a seven-month-old male cocker spaniel dog. The clinical, microbiological, biochemical, radiographic and ultrasonographic examinations ruled out neoplasia, congenital disease and infectious disease. The anamnesis revealed that the owner had vaccinated the dog seven times, one vaccination per month, without veterinarian supervision. In both kidneys, severe thickening of the glomerular capillary walls was observed. Electron microscope examination revealed a large number of electron-dense deposits that were primarily in the glomerular subendothelial spaces and the basal membrane, which is compatible with antigen-antibody complexes. The immunohistochemical examination revealed that the antigen present in the glomeruli corresponded with the antigen present in the vaccine. We report a type III hypersensitivity nephropathy in a young dog, which was possibly caused by over-vaccination.     

Extraskeletal osteosarcoma of the heart presenting as infective endocarditis

A 7 yr old castrated male Labrador retriever (35.6 kg) was evaluated for an acute onset of vomiting of 24 hr duration. On initial examination, the patient was febrile (103.8°F) and tachycardic (150 beats/min). Thoracic radiographs revealed left atrial enlargement with mild pulmonary infiltrates. The dog's condition worsened and repeat radiographs revealed worsening pulmonary infiltrates and pleural effusion. Treatment for heart failure was initiated. An echocardiogram showed a large 3 cm × 4 cm vegetation on the atrial surface of the posterior mitral valve. The patient was euthanized due to poor clinical appearance and infective endocarditis was suspected. Necropsy revealed an osteosarcoma of the posterior mitral valve, which cultured negative.     

Single-phase methylene diphosphate bone scintigraphy in the diagnostic evaluation of dogs with osteosarcoma

In this study, 25 dogs each with a histopathologically diagnosed appendicular or axial osteosarcoma were prospectively and consecutively examined by methylene diphosphate nuclear scintigraphy. Scannings that revealed scintigraphically enhanced focal increased activity via bone uptake of the 99mTc methylene diphosphate radionuclide at sites other than the primary tumor site were compared with scintigrams obtained from dogs without osteosarcoma. Secondary scintigraphic sites were evaluated by survey radiography and, if possible, by histologic examination (biopsy or necropsy specimens). On the basis of our findings, scintigraphy seems to be more efficient than physical examination and radiographic bone survey for the diagnosis of multicentric, metachronous, or metastatic canine osteosarcoma.