Measurement of brain trace elements in a dog with a portosystemic shunt: relation between hyperintensity on T1-weighted magnetic resonance images in lentiform nuclei and brain trace elements.

Prior to euthanasia, brain magnetic resonance imaging (MRI) was performed for a five-year-old male Yorkshire Terrier following portosystemic shunt (PSS) surgical attenuation. Hyperintensity was observed on T1W images of the lentiform nuclei. Trace elements in this area were measured by inductively coupled plasma atomic emission spectrometry. The manganese concentration in the lentiform nuclei was four times higher than that in the control group. Therefore, the manganese accumulation would be the substance that causes the hyperintensity on T1W images of the lentiform nuclei in PSS dogs.

Treatment of prostatic abscesses by aspiration of the purulent matter and injection of tea tree oil into the cavities in dogs.

Ultrasonography-guided transabdominal needle aspiration was carried out to remove 3 to 14 ml of purulent matter from the cavities of prostatic abscesses in 6 dogs, and the same volume of tea tree oil was injected into the cavities to treat the abscesses. The same treatment was repeated 3 weeks later in 4 dogs, and subsequent disappearance of the purulent matter in the cavities and a marked reduction in the volume of the cavities were observed. These findings indicate that the treatment of prostatic abscesses by aspiration of the purulent matter and injection of tea tree oil into the cavities is very effective in dogs.

Changes in activities of enzymes related to energy metabolism in canine lymphoma cells.

Alterations in the activities of enzymes related to energy metabolism in canine lymphoma cells were investigated. Cytosolic pyruvate kinase (PK) and mitochondrial malate dehydrogenase (MDH) activities in lymphoma cells were significantly higher than those in lymphocytes obtained from lymph nodes of healthy dogs, whereas cytosolic lactate dehydrogenase (LDH) activity was significantly lower in lymphoma cells. The cytosolic M/L ratio (MDH activity/LDH activity), which is considered to be a good indicator of energy metabolism related to glucose utilization in animal tissues, was significantly higher in lymphoma cells than in the normal lymphocytes.

Gallbladder lymphoma in a miniature dachshund.

A 7-year-old, miniature dachshund was referred for examination and treatment of persistent anorexia, deep yellow-coloured urine and leucocytosis. The clinical sign of jaundice, results from a serum biochemistry profile and ultrasonographic images suggested a biliary tract obstruction. A cholecystectomy was performed to remove the obstruction. Histopathological assessment of the resected gallbladder and partial common bile duct indicated diffuse large B-cell lymphoma. Twelve days after the initial operation, a second procedure was performed due to bile leakage into the abdominal cavity. Chemotherapy was administered twice after the second operation but discontinued, because the dog showed adverse effects. The dog is still alive 24 months after the surgery. To the authors' knowledge, this is the first description of canine gallbladder lymphoma.

Acquired mitral stenosis in a cat with hypertrophic cardiomyopathy.

A seven-year-old castrated male domestic shorthair cat was diagnosed with hypertrophic cardiomyopathy (HCM) and suspected mitral stenosis (MS) based on electrocardiography, thoracic radiographs and echocardiographic findings. Post-mortem examination of the heart revealed morphological features consistent with HCM. In addition, there was marked fibrous deposition on the surfaces of the chordae tendineae extending to both mitral valve leaflets, which caused total chordal fusion into pillars of fibrous tissue and fusion of the commissures. The present case indicates that acquired MS can occur in association with HCM in the cat.

Pressure-flow relationship and longitudinal distribution of pulmonary vascular resistance in heartworm-infected dogs.

The pressure-flow relationships and the longitudinal distributions of pulmonary vascular resistance in normal and heartworm-infected (HWI) dogs were compared in an isolated, blood perfused preparation. The pulmonary circulation was partitioned into pulmonary arterial, middle, and venous segment based on the concept of a five element lumped model. The pulmonary arterial pressure-flow relationships were found to be non-linear and convex to the pressure axis in both normal and HWI lungs. The pressure-flow relationships of the pulmonary arterial and venous segment were linear and these slopes in the HWI lungs were significantly higher than the normal lungs. The pressure gradient of the middle segment was increased as flow increased at lower flow range, however, it was not increased during higher perfusion range in both lungs. At higher flow, the pressure gradient of the middle segment in the HWI lungs was significantly higher than the normal lungs. These results suggest that the ohmic resistance was almost equal to the sum of the two slopes of the pressure-flow relationships of the pulmonary arterial and venous segment because the pressure gradient of the middle segment was not altered as flow increased during higher perfusion rate. Because the slopes of the pressure-flow relationships of the pulmonary arterial and venous segment were increased with heartworm infection, the ohmic resistance of HWI lungs would be higher than normal lungs. The intercept pressure on the pressure axis of the linear portion of the pulmonary arterial pressure-flow relationship, a critical closing pressure, was regarded as pressure gradient of the middle segment during higher perfusing rate because the intercept pressures of pressure-flow relationships of pulmonary arterial and venous segment were almost equal to zero. Therefore, the critical closing pressure of HWI lungs would be higher than normal lungs. The pulmonary hypertension of filariasis appears to be due to an increase in ohmic resistance and elevated critical closing pressure.

Hypertrophic cardiomyopathy in an aged dog.

A 14-year-old female Yorkshire terrier was presented with the complaint of cardiac murmur and convulsive seizure. Thickened mitral valve, left atrial enlargement, excess motions of the left ventricular (LV) free wall and the ventricular septum, and tricuspid, mitral and aortic valve regurgitations were recognized on echocardiography. Follow-up echocardiography revealed the progression of concentric LV hypertrophy and LV outflow obstruction. Clinical symptoms associated with cardiac failure did not develop during the observation period. The pathological examination of the heart revealed that the dog had the morphological hallmarks of hypertrophic cardiomyopathy: massive ventricular hypertrophy, disorganization of cardiac muscle cells, interstitial myocardial fibrosis, and abnormal intramural coronary arteries.

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.

Ebstein's anomaly in a beagle dog.

An intact male beagle dog aged 1 year was referred because of shortness of breath, exercise intolerance and cardiac murmur. Based on the results from electrocardiography, thoracic radiography and echocardiography, the dog was diagnosed as Ebstein's anomaly. Although the orally administered digoxin, vasodilators and diuretics partially improved congestive signs, the dog became to be refractory and died 20 months after the diagnosis. Necropsy confirmed malformation and apical displacement of the basal attachment of tricuspid valve leaflets.

An evaluation of radiographic hepatic size in dogs with portosystemic shunt.

Radiographically, the hepatic sizes of portosystemic shunt (PSS) cases were evaluated. In this study the hepatic area was compared in PSS and non-PSS dogs by utilizing the right lateral radiography. The top three breeds of PSS dogs of Maltese, Shih Tzu and Yorkshire Terrier, were included and these dogs had a significantly smaller hepatic area ratio of 46.37 +/- 0.63%, 61.76 +/- 0.78% and 41.59 +/- 0.23% respectively (p<0.05) and the average overall hepatic area in the 3 dog breeds was 47.75 +/- 0.40%.

A suspected case of ornithine transcarbamylase deficiency in a cat.

An 18 month-old, intact female American Shorthair cat was presented for evaluation of stunted growth and postprandial depression. Fasting serum ammonia and serum bile acid concentrations were above reference ranges at 396 microg/dl and 6.5 micromol/ l and their postprandial concentrations were 785 microg/dl and 9.5 micromol/l, respectively. The initial tentative diagnosis of a portosystemic shunt was excluded by mesenteric portography and histopathology of the liver. The cat was then suspected of a urea cycle enzyme deficiency and its urine was analyzed by gas chromatography-mass spectrometry. A presumptive diagnosis of ornithine transcarbamylase deficiency was made on the basis of the detection of orotic acid and uracil.

A simple calculation for obtaining shunt fractions of portosystemic shunts.

Since the isotopes can not be utilized for veterinary patients in Japan, the authors developed a simple calculation formula of shunt fraction of portosystemic shunt based on the hepatic circulation model. The shunt fraction can be calculated utilizing only 2 portal pressure measurements of pre-shunt ligation and temporary or permanent shunt ligation. The calculated shunt fraction can obtained pre-ligation and post-ligation either temporally or permanent complete shunt ligation: complete ligation group of PSS (n=59) had 48.2 +/- 16.9% of shunt fractions, whereas the partial ligation group (n=48) had 71.6 +/- 10.7% of shunt fractions.

Portal vein aneurysm in a dog.

Portal vein aneurysm (PVA) is a rare abnormal dilatation of the portal vein, which has not been reported in dogs. We describe the findings of ultrasound and computed tomography in a case of PVA in a young male toy poodle, with the final diagnosis established by explorative surgical observation. The dog had an aneurysmal fusiform dilatation in the extrahepatic portal vein with portal hypertension and multiple portsystemic shunts. This is the first report of canine PVA.

Healing of wound sutures on the mitral valve: an experimental study.

OBJECTIVE: The aim of this study was to examine the histopathological changes that occur during the heading process of a sutured wound on the mitral valve. METHODS: In 12 mongrel dogs, an incision was made at a right angle to the annulus at the center of the free edge of the anterior mitral leaflet and then sutured. Animals were killed 2-16 weeks later and the wounds were examined histologically. RESULTS: Two weeks after the operation, fibrin thrombi were found on the atrial surfaces of the wound, and organized thrombi became part of the neointima thereafter. There were capillaries in the thrombi, but only a few extended from the valvular ring. On the ventricular surfaces, fibrous neointima extending from adjacent intima without capillary proliferation covered the wound at 2 weeks. These heading processes started from the valvular ring side of the wound. Processes were delayed near the free edge area, and myxomatous granulation tissue extended from the adjacent spongiosa. There were abundant collagen fibers obscuring the suture line at 4 weeks in the basal region and at 12-16 weeks near the free edge. Calcified deposits with cartilage were found in a thick scar in the basal region at 4 weeks and extended to the central area thereafter. CONCLUSION: The healing of mitral valvular wounds is slow, especially near the free edge area. The wound is covered by organized thrombi at the atrial surface and by fibrous sheaths at the ventricular surface. These processes should be taken into consideration during the patients' care after valvoplasty, especially during the first several months after surgery.

Brain magnetic resonance imaging characteristics in dogs and cats with congenital portosystemic shunts.

Animals with a portosystemic shunt (PSS) often have neurologic abnormalities. Diagnostic imaging, including brain magnetic resonance (MR) imaging, is not performed routinely in these animals. In this study, brain MR images were obtained in 13 dogs and three cats with a PSS, and in 15 dogs and five cats that were neurologically normal and used as controls. All animals with a PSS had widened sulci. In addition, 10 out of 13 dogs with a PSS and one out of three cats with a PSS had hyperintense focal areas in the lentiform nuclei on T1-weighted (T1W) images, which did not enhance after intravenous gadolinium. Following surgical correction of the PSS, MR imaging examinations were repeated in one dog and one cat. The hyperintensity of the lentiform nuclei had decreased. This study indicates that MR imaging findings of widened sulci and hyperintensity of the lentiform nuclei on T1W images may be found in dogs and cats with a PSS.