Mast cell tumours (mastocytosis) in the horse: A review of the literature and report of 11 cases

Mast cell tumours are uncommon tumours in horses, compared to some other species of domesticated animals. They are most frequently located in the skin, but they can also arise at other sites, including the upper respiratory tract and eye. Cytology or histopathology is required for diagnosis. Treatment options include surgical excision, laser ablation, cryotherapy, intralesional injection of corticosteroids or water, and radiotherapy. Malignant and systemic forms are very rare.     

Carcinocythemia: First report in a cat and literature review

A 6‐year‐old female neutered European Shorthair cat was presented with a 2‐day history of lethargy and hyporexia. On physical examination, the cat was slightly depressed and had a 2.5 cm nodule in the left 3^rd mammary gland. The hemogram revealed mild leukocytosis with mature neutrophilia and moderate thrombocytopenia. On blood smear evaluation, rare pleomorphic cells, possibly of epithelial origin, were observed mainly at the feathered edge. The animal died about 12 hours after presentation, and a necropsy was performed. On histopathology, the mammary nodule was diagnosed as a tubulopapillary adenocarcinoma with vascular invasion and widespread metastases. Immunocytochemical tests for cytokeratins (AE1/AE3) confirmed the epithelial phenotype of the neoplastic cells observed on the blood smear. The present report describes a feline mammary carcinoma with widespread metastases and the presence of malignant epithelial cells in the peripheral blood referred to as carcinocythemia. This condition has been previously described in people and dogs. To the author's knowledge, this is the first reported case of feline carcinocythemia. As in other species, the phenomenon was associated with a terminal phase of systemic malignancy.     

Brain tumours in the dog: Treatment of 10 cases and review of recent literature

This paper records preliminary results achieved in 10 dogs with histologically confirmed intracranial tumours treated by a variety of methods. One case was treated by surgical excision alone, three cases by surgical excision and external beam radiotherapy, one by surgical excision followed by cytotoxic chemotherapy (lomustine), two by radiotherapy alone, two by chemotherapy alone, and a combination of all modalities was used in one case. Palliation of clinical signs was acheived to varying degrees in all but one case and the quality of life was much improved in nine out of 10 animals. Survival times following first treatment varied from 10 days to 16 months. One dog is still alive with no deficits at 12 months following first treatment (surgery). These results and those reported else-where are discussed.     

Feline cytauxzoonosis: a case report and literature review

A 5.5-year-old Siamese presented for evaluation of a three-day history of anorexia and lethargy. Upon physical examination, the cat was depressed, dehydrated, pyrexic, had injected conjunctiva and sclera, pale mucous membranes, and a grade II/VI systolic heart murmur. Thoracic radiographs revealed moderate to severe, diffuse, bronchointerstitial pulmonary changes with enlarged and tortuous pulmonary vessels. With continued hospitalization, the cat became dyspneic and died. The postmortem cytopathological examination of the liver, spleen, and lung impressions revealed reticuloendothelial cell infection with Cytauxzoon felis.     

Penile and preputial tumours in the horse: literature review and proposal of a standardised approach

Penile and preputial tumours are not uncommon in the horse, but can cause discomfort and lead to serious complications. Several types of tumour of the male external genitalia have been described. The most common type is the squamous cell carcinoma (SCC), which is found mainly in older horses. Reports of a breed predilection for penile tumour formation are equivocal, but castration, coat colour, poor hygiene and various infectious agents have all been suggested to predispose to the development of some types of tumour (e.g. SCC, papilloma and melanoma). Careful assessment of the primary tumour is an important first step in the design of an optimal treatment protocol. Invasiveness, differentiation grade, tumour size and presence of metastases are all relevant to the decision to pursue additional diagnostic procedures or specific treatment options. To date, no standard protocol has been reported for the approach to penile tumours in the horse and treatments range from minimally invasive therapies (e.g. topical use of 5-fluorouracil) to radical surgical interventions (e.g. en bloc penile and preputial resection with penile retroversion). Completeness of removal of the neoplasm and therefore risk of recurrence is highly dependent on the type of therapy chosen. However, the size and histopathological features of the primary tumour are also important factors with respect to the likelihood of recurrence. This review describes the most common penile and preputial neoplasms in the horse, and outlines a standard protocol aimed at arriving at a specific diagnosis and tailoring the therapeutic approach accordingly.     

Bovine pheochromocytoma: case report and review of literature.

A pheochromocytoma had partially replaced the left adrenal gland of a mature, grade Hereford cow and had penetrated the caval wall with resultant production of an intravascular nodule having a diameter of 2 cm. A few small neoplastic emboli were in thin-walled capsular and trabecular blood vessels. Metastasis to other tissues was not demonstrated.     

Olfactory ganglioneuroblastoma in a dog: case report and literature review

A 7-y-old, intact male Alaskan Malamute was presented with a 3-mo history of stertor and epistaxis. Computed tomography of the skull revealed generalized loss of gas throughout both nasal passages with replacement by a soft tissue mass that traversed the cribriform plate. Histopathology revealed neoplastic neuroblast cells arranged in anastomosing cords, as well as separately located aggregates of ganglion cells. Both neoplastic cell populations demonstrated immunoreactivity to MAP-2, TuJ-1, and synaptophysin. Neuroblastic cells additionally exhibited punctate immunoreactivity to MCK and CK8/18. We document here both the positive neural immunohistochemical markers for this neoplasm, as well as propose possible histomorphologic variants.     

Management of generalized gingival enlargement in a dog--case report and literature review

The present report describes treatment of a dog with generalized gingival enlargement and serves as a review of etiology and treatment options for this condition. The combined use of scalpel blade, electrosurgical equipment, and a 12-fluted bur on a high-speed handpiece with water irrigation allowed for accurate excision of excess gingival tissue and contouring of remaining gingiva. Surgery coupled with professional dental cleaning/periodontal therapy can decrease the recurrence of this condition. In addition, home oral hygiene is an important component of the treatment plan. The history of patients with gingival enlargement should be reviewed carefully, including drug history and previous medical conditions, in an attempt to elucidate a specific cause and thus allow for greater long-term success.     

Q fever osteomyelitis: a case report and literature review

Q fever is a worldwide zoonosis caused by Coxiella burnetii. The clinical manifestations of Q fever include endocarditis, pneumonitis and hepatitis. Disease awareness and evolving diagnostic tests have enabled the recognition of unusual manifestations of Q fever. We report a case of Q fever osteomyelitis. A 51-year-old patient was admitted to hospital because of fever, leg weakness, and asthenia. His past medical history included surgery and a bone graft for the treatment of a giant cell tumor on the distal part of the femur. Blood and bone biopsy cultures were negative. Bone histological examination was consistent with a sub-acute or chronic inflammatory reaction that involved foci of epithelioid and gigantocellular infiltrates and necrosis. Serology testing revealed high antibody titers to C. burnetii antigens (phase I: IgG 3200; IgA 200; phase II: IgG 6400; IgA 400), which is indicative of chronic Q fever. The specific Polymerase Chain Reaction (PCR) of the abscess sample from the femoral region was positive for C. burnetii. The patient was treated for chronic Q fever with doxycycline and hydroxychloroquine for 18 months and recovered gradually without recurrence of pain or functional impairment. Q fever osteomyelitis is a rare and most likely underestimated disease. Epithelioid and gigantocellular granulomatous osteomyelitis in the context of culture-negative bone specimens should raise suspicion of Q fever. Serological tests, specific PCR and cell culture can provide evidence of a C. burnetii infection. Although bone diffusion may be a concern, the currently recommended treatment for Q fever was effective in this case.     

Canine mycetoma: a case report and review of the literature

This paper describes a mycetoma of the fourth tarsal bone of a 5-year-old spayed Corgi-cross bitch caused by the eumycete Curvularia geniculata. The condition was treated successfully by surgical excision, followed by chemotherapy using iodine, trimethoprim-sulphadiazine, amphotericin B. dimethyl sulphoxide. thiabendazole and nystatin. An attempt was made to establish the in vitro minimum inhibitory concentration of various antifungal drugs on the causative organism. No clinical or radiological evidence of recurrence was found 3 years after initiation of treatment, despite the original poor prognosis.     

Pneumocystis carinii in the miniature dachshund: Case report and literature review

This article reviews Pneumocystis carinii and presents four cases in the miniature dachshund. The cases presented with hyperpnoea, tachy-pnoea and exercise intolerance. There were also clinical signs suggestive of immune incompetence in all the dogs. P carinii pneumonia was diagnosed in all four cases on transtracheal aspirate cytology. Immunological studies showed low globulin levels on serum electrophoresis, decreased lymphoblast transformation response (in the two cases that were tested) and a deficiency of immunoglobulins A, G and M. Light and electron microscopy as well as anti-canine immunoglobulin G immunoperoxidase staining studies were performed on one case which had died because of the disease. From these four cases, it appears that P carinii pneumonia in the miniature dachshund may be the result of an immunodeficiency. It does not, however, appear to be a classic primary severe combined immunodeficiency syndrome as the dogs appeared to respond to treatment, did not show growth failure and did not manifest overwhelming commensurate bacterial infections.     

Nerve sheath tumors in cattle: literature review and case report]

Incidence, clinical signs, pathomorphological findings, differential diagnosis and prognosis of bovine nerve sheath tumours are reviewed. Own clinical and pathomorphological findings are described in an eight years old cow with a benign SCHWANNoma of the eight spinal nerve.     

Pylorogastric intussusception in the dog: a case report and literature review

A 10-month-old, neutered male Saint Bernard presented for evaluation of acute, severe vomiting. A soft-tissue mass was noted within the stomach on survey abdominal radiographs. The diagnosis of pylorogastric intussusception was made during exploratory celiotomy. The intussusception was manually reduced at surgery, the pyloric antrum was enlarged, and the duodenum was permanently affixed to the abdominal wall in an attempt to prevent recurrence of the intussusception. The dog recovered, has gained weight (5 kg), and has had only one isolated episode of vomiting during the one year since discharge from the hospital. This report documents the fourth reported case of pylorogastric (i.e., duodenogastric, gastrogastric) intussusception in the veterinary literature and is the first report that details the surgical management of the disease.     

Cytologic features of testicular tumours in dog

In this paper, we report on our experience of cytology of fine needle biopsies performed on 92 dogs with testicular tumours during the period from 1998 to 2002. Cytological diagnosis was consistent with seminoma in 20 cases, sertolioma in 16 cases, Leydig cell tumours in 50 cases and mastocytoma in one case. Five cases could not be diagnosed by cytology. Cytological observations were confirmed after surgery by histopathological examination in 87 cases. Cytology provided a sensitivity of 95% for seminoma, 88% for sertolioma and 96% for Leydig cell tumours. The specificity was 100% for all three tumour types. In our experience cytology of fine needle aspirations of testicular tumours is a very reliable technique.     

Intestinal ganglioneuroma in a kitten–a case report and review of literature

An intestinal ganglioneuroma of a 6–week–old male kitten is described. The neoplasm was well circumscribed and involved a 6–5–cm segment of the jejunum, which was dilated and had a 6–10 mm thick wall. It was characterized histologically by irregularly–arranged bundles of nerve fibres, with Schwann cells and single or groups of round or angular ganglion cells. Some of the ganglion cells had satellite cells. Vessels with prominent endothelial cells, and islands of epithelial cells forming acini, were also seen. The age of the kitten and slow nature of growth of this tumour led the authors to believe that this is a case of congenital neoplasia. This is the first report of an intestinal ganglioneuroma in a cat.     

Rickets in a Thoroughbred-cross foal: case report and review of the literature

Rickets is a metabolic bone disease associated with failure of endochondral ossification and impaired osteoid mineralization in growing animals. As a consequence, affected individuals can develop gross and microscopic bone malformations. The most common causes of rickets in domestic species include vitamin D and phosphorus deficiency. Rickets has been described in multiple species; however, comprehensive postmortem characterizations with confirmatory histopathology in equids have not been published. A 6-mo-old, Thoroughbred-cross foal was diagnosed with rickets based on gross autopsy findings and microscopic examination of the ribs and long bones. Grossly, all costochondral junctions of the ribs were enlarged with a “rachitic rosary” appearance, and there were multiple fracture calluses in the rib bodies. Epiphyses and metaphyses of the long bones appeared widened on sagittal section, and their physes were irregularly thickened. Histologically, there were poorly organized columns of hypertrophic chondrocytes within the physes of affected bones, islands of chondrocytes embedded within the primary and secondary spongiosa, and faintly eosinophilic seams of poorly mineralized osteoid within the bone trabeculae. Areas of focally increased osteoclastic activity were observed in some of the sections, perhaps pointing to a more complex metabolic bone disease in a growing animal. Low serum concentrations of calcium and 25-hydroxyvitamin D were detected in an antemortem sample. The pathogenesis of these imbalances was not definitively established, but lack of sunlight exposure, low concentration of vitamin D precursors in the diet (perhaps secondary to malnutrition), or both, were suspected; a genetic basis cannot be ruled out.