A castrated male, 4-year old, Dachshund weighing 5.3 kg with an acute history of anorexia, vomiting, severe depression, and hypothermia for 1 day was referred. Severe leukopenia, mild increased hepatic enzymes, and mild imbalanced electrolyte were found on laboratory tests. There are no remarkable findings on abdominal radiographs. Ultrasonography showed multifocal heterogeneous and hypoechoic round regions in the liver. Ultrasound guided fine needle aspiration and drainage were performed and hepatic abscess was diagnosed. The patient was recovered normally without any complications through aggressive medical treatments from the result of culture and sensitivity test.

A 10-year-old female Yorkshire terrier with the clinical signs of nasal swelling, epistaxis and nasal discharge was presented to the Veterinary Teaching Hospital in the Cheju National University. Abnormal nasal mass detected in physical examination and radiographic findings. After surgical excision, the sample of nasal mass was referred to Pathology Department of Veterinary Medicine. Grossly, the mass was soft, friable, and 2.5 × 4 cm in size. Histopathologically, the mass was composed of medium-sized non-keratinizing columnar to polyhedral cells arranged in anastomosing ribbon and large nest. It has complex in-folding of thick epithelial layers separated by fibrovascular septa. Tumor cells showed characteristic palisading arrangement of columnar cells, and perpendicularly distributed to the basement membrane. The cells had pale basophilic cytoplasm, oval nucleus and one or more nucleoli, and indistinct cellular border. Many tumor cell emboli were presented in lymphatics. Immunohistochemistry revealed that tumor cells were cytokeratic (CK) 19 and CK clone MNF116 positive and but CK7 and CK high molecular weight negative. Based on the gross, histopathologic, and immunohistochemical findings, the mass was diagnosed as transitional carcinoma in nasal cavity. In our best knowledge, this is the first report of transitional carcinoma originated from transitional zone of canine nasal cavity in Korea.

A neutered male, 8-year-old, Pekingese, weighing 4.3 kg with a history of anorexia, sneezing, nasal discharge, and epistaxis for one month was referred. Soft tissue swelling around the nasal bone and small defects of the hard palate with a tiny round dark red mass were found on physical examination. The laboratory tests represented mild leukocytosis. On skull radiographs, soft tissue swelling and osteolytic change of the incisor bone, nasal bone, and maxilla were found. On computed tomography scan images, there was soft tissue attenuating opacity with calcified spots in the bilateral nasal cavities and frontal sinuses. Loss of nasal turbinate pattern and nasal septum was found. And destruction of the insicor bone, nasal bone, maxilla, hard palate, perpendicular palatine bone, and cribriform plate were identified. Nasal malignant melanoma was confirmed by nasal biopsy.

Mesenteric torsion was diagnosed in a 2-year-old, spayed female Miniature Schnauzer. The patient was presented with acute depression, vomiting, lethargy and hematochezia. On physical examination, severe dehydration, tachycardia, tachypnea, weak femoral pulse, delayed capillary refill time and pale mucous membrane were found and the dog was in shock. Radiography and ultrasonography revealed intestines distended with gas, ascites and the "C" shaped distended intestine. Medical treatments including fluid therapy, analgesics, antibiotics and lidocaine for reducing reperfusion injury were applied. And then, the mesenteric torsion was definitively diagnosed through exploratory laparotomy and intestinal resection and anastomosis were performed. The dog made an uneventful recovery and was free of clinical sign one week after surgery. Mesenteric torsion is an unusual and life-threatening disease in dogs. It has usually been described in the middle and large breed dogs, especially German Shepherds. However, the mesenteric torsion should be included in the differential diagnostic lists for acute abdomen even in small breed dog. The mortality rate of mesenteric torsion can be reduced through prompt diagnosis, proper preventive therapy for shock and reperfusion injury and emergency surgery.

A 2-year-old, female, Maltese dog (3.2 kg of body weight) was referred to the Veterinary Medical Teaching Hospital, Chungnam National University with vomiting, anorexia and depression. Twelve hours prior to the onset of clinical signs, the dog ingested some grape skins (about 60 g). Physical examination at the time of presentation showed peripheral edema and mucous pallor. Blood and blood chemical analysis revealed anemia and moderate azotemia with elevated blood urea nitrogen (107.2 mg/dl), creatinine (6.3 mg/dl) and hyperphosphatemia (11.3 mg/dl). Echogenicity of renal cortex were observred by ultrasonography. The dog was diagnosed as acute renal failure occurred by grape skin toxicosis. The dog was treated with supportive care such as fluid therapy, diuretics (furosemide) and phosphorus binder (almagate). A normal condition of blood and blood chemical findings and clinical signs was observed at five days after treatment, and prognosis is good to date.

Gastrointestinal stromal tumor (GIST) is one of the mesenchymall tumors originated from gastrointestinal submucosa. A 10 year-old, male, mixed breed dog with persistent diarrhea, anorxia and lethargy was referred to Haemaru Animal Referral Hospital. Large mass originated from the transverse colon was observed and large amount of ascites and free gas were found on abdominal radiography and ultrasonography. The ascites was septic exudate mixed with bacteria that consisted with intestinal perforation. These was no metastatic lesion. This mass was tentatively diagnosed as adenocarcinoma, leiomyosarcoma (LMS) and lymphosarcoma and surgical resection and histilogical examination were planned. However, according to owner's request, the patient was euthanized and then the necropsy was performed. About 10 cm sized mass originated from the cecum, ascending colon and transverse colon was adhered to surrounding mesentery and the perforation and large amount of asicites were observed. GIST was suspected on histopathologic examination and confirmed according to CD117 expression in immunohistochemistry. GIST, derived from interstitial cells of Cajal, can be distinguished from LMS and leiomyoma (LM) on the basis of expression of CD117 (KIT) immunohistochemically. GIST has a different biological behavior and clinical course compared with LMS and LM, therefore definite diagnosis for GIST using immunohischemistry is clinically important to predict the precise prognosis of the patient.

Portosystemic shunt (PSS) was diagnosed in 43 dogs by mesenteric portogram from January, 2002 to June 2007 in Haemaru referral animal hospital. PSS was found in various breeds including Maltese, Miniature Schnauzer and Yorkshire Terrier and there was no predisposition in gender. In laboratory parameters, mean cell volume was lower than normal value in single shunt and alanine aminotransferase was higher than normal range in multiple shunts with clinical significance. Cystic calculi were found in over 50% dogs with PSS and even in 70.8% dogs with single shunt. In 81% dogs with PSS, extrahepatic single shunt such as portocarval type and portoazygous type was identified. Extrahepatic multiple shunt and intrahepatic single shunt were observed in 4 dogs, respectively. Gradual attenuation using ameroid constrictor was applied to 35 dogs with extrahepatic single shunt and the prognosis of these dogs were good except two dogs, which showed poor prognosis because of acquired multiple PSS and renal disease unrelated with PSS, respectively.

A 4-year-old female Cocker spaniel was presented with respiratory distress and abdominal distension. Pleural effusion, ascites, hepatosplenomegaly, and superficial lymphadenopathy were observed and multicentric lymphoma was diagnosed by cytological examination. Immunophenotyping of lymph node and bone marrow using polymerase chain reaction for antigen receptor rearrangement identified a stage V lymphoma origination from T-cell. Despite of systemic chemotherapy using L-asparagenase, vincristine, cyclophoaphamide and prednisolone, neurologic deficits came out and progressed. Cerebrospinal fluid analysis revealed neoplastic lymphocytic pleocytosis indicating central nervous system involvement of lymphoma. The postmortem diagnosis was confirmed based on the histology and imunohistochemistry.

Granulomatous meningoencephalomyelitis (GME) is a sporadic, idiopathic, non suppurative inflammatory disease of the canine central nervous system. GME appears to have a worldwide distribution and to occur mostly in young to middle-age dogs of small breeds. A 6-year-old female mixed dog with wry neck, ataxia and rolling was submitted to the Cheju National University for diagnosis. Grossly, in the brain, cerebrospinal fluid was mildly increased and dilatation of the subarachnoid blood vessels was observed. Histopathologically, the lesions were characterized by perivascular cuffs of lymphocytes, various numbers of macrophages and plasma cells in the brainstem and cerebral white matter. Numerous granuloma composed of lymphocytes and histiocytes were scattered throughout the brainstem. Two malacic foci characterized by axonal swelling and gitter cell infiltration with hemorrhage were noted in the medulla oblongata and cerebellum. Special stains failed to demonstrate any infectious agents. Immunohistochemically, the infiltrated cells demonstrated strong positive reactions for CD3, a marker for T lymphocytes origin. Based on the clinical signs, histopathology, and immunohistochemistry, this case was diagnosed as GME in a mixed dog.

A 17-month-old intact male Cocker Spaniel was presented with primary complaints of severe ascites, exercise intolerance, and diarrhea. Diagnostic studies revealed tricuspid and pulmonic regurgitation on phonocardiogram, right ventricular enlargement on the electrocardiogram, typical right cardiac enlargement signs on the thoracic radiography and tricuspid valve malformation and marked enlargement of the right atrium and right ventricle on the echocardiography and tricuspid and pulmonary regurgitation on the color spectral echocardiography, suggesting tricuspid valve dysplasia and pulmonary hypertension. Using angiography and cardiac catheterization, pulmonary hypertension was ruled out. Further echocardiographic study revealed membranous valvular structures cranial to pulmonary annulus causing pulmonary regurgitation. Based on these findings on the diagnostic investigation, the case was diagnosed as tricuspid valve dysplasia complicated with pulmonic regurgitation. The dog was medically managed with furosemide, enalapril, nitroglycerine transdermal patch and pimobendan after the ascitic fluid removal.