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.     

Obstructed portal venous flow and portal vein thrombus in a dog

A young adult Doberman Pinscher had clinical signs and laboratory data consistent with the copper-associated hepatopathy commonly found in Doberman Pinschers. Hepatic biopsy and hepatic copper analysis did not support this diagnosis. Furthermore, changes seen in the hepatic biopsy specimen did not explain the acquired portosystemic shunting or the portal hypertension that the dog had. A mesentery venoportagram revealed markedly delayed filling of one portal vein, and necropsy revealed a small thrombus partially occluding that hepatic vein. It was not determined whether obstructed portal venous flow caused the portal vein thrombus or vice versa; however, it was theorized that the portal vein thrombus, once formed, contributed to further portal hypertension and/or delayed portal vein filling.     

Severe pulmonary arterial hypertension due to Angiostrongylosus vasorum in a dog

A dog was presented with a history of dyspnea, coughing, and ascites. Angiostrongylosis and severe pulmonary arterial hypertension (PAH) were found, as well as a marked discordance between the electrical and mechanical events of the heart. Pulmonary arterial hypertension related to Angiostrongylus vasorum has rarely been reported.     

Ascites due to pre-sinusoidal portal hypertension in dogs: a retrospective analysis of 17 cases

Accumulation of a pure transudate abdominal effusion in the absence of significant hypoalbuminaemia is uncommon in dogs and is due to pre-sinusoidal portal hypertension. Reported causes of pre-sinusoidal portal hypertension vary, but suggest a reasonable prognosis. A retrospective analysis of 17 dogs that presented to our institution with ascites due to pre-sinusoidal portal hypertension identified idiopathic hepatic fibrosis or canine chronic hepatitis as the underlying cause in the majority of cases. Twelve (70.5%) dogs were 4 years of age or younger at time of presentation. Total serum protein was higher in dogs with chronic hepatitis than it was in dogs without inflammatory disease. The prognosis was generally poor and no histological, imaging or biochemical parameters were useful as prognostic indicators. Dogs died or were euthanased due to severe clinical signs associated with the portal hypertension and/or perceived poor prognosis.     

Portal streamlining as a cause of nonuniform hepatic distribution of sodium pertechnetate during per-rectal portal scintigraphy in the dog

The purpose of this study was to evaluate nonuniform patterns of vascular distribution of pertechnetate in the dog during per-rectal portal scintigraphy. Ninety-two studies were reviewed retrospectively to document the patterns of radionuclide distribution. Forty-five studies were classified as normal and 47 were classified as diagnostic for a macrovascular portosystemic shunt. In these dogs, shunt fractions were calculated and compared using a t-test. In dogs with sufficient liver radioactivity for evaluation, the study was classified as having uniform, dorsal, central, or ventral radiopharmaceutical distributions. There were 51 animals (45 normal and six dogs with low-magnitude portosystemic shunts) with sufficient liver activity to assess the radionuclide distribution within the liver. A one-way ANOVA was used to compare shunt fractions between each of the distribution patterns. Two dogs were anesthetized and selective portovenograms were performed. Portovenograms were compared with the scintigraphic images to correlate the vascular distribution of the right, central, and left divisional branches of the portal vein. The shunt fraction in the 45 normal dogs was significantly lower than in the dogs with portosystemic shunts (5.7% +/- 4.8% vs. 78.6% +/- 20.0% (mean +/- SD), P < 0.001). Of the 51 dogs with sufficient liver activity to classify the pattern of distribution, there were 15/51 (31.4%) with uniform radionuclide distribution, 10/51 (19.6%) with focal dorsal distribution, 15/51 (29.4%) with focal ventral distribution, and 10/51 (19.6%) with focal central distribution. There was no significant difference in the shunt fractions between the groups. There were six dogs diagnosed with low-magnitude portosystemic shunt with sufficient liver radioactivity to categorize the vascular distribution of the radionuclide within the liver. Of these six dogs, two had focal dorsal distribution, one had focal central, one had focal ventral and two had uniform distribution. Focal dorsal distribution could result from streamlining of the radionuclide into the right divisional branch of the portal vein. Focal ventral distribution could result from streamlining the radionuclide into the left divisional branch of the portal vein. Focal central distribution could result from streamlining the radionuclide into the central divisional branch of the portal vein.     

Acquired extrahepatic portosystemic shunts in a young dog

A young, male miniature poodle was presented with severe neurological problems. Laboratory tests and ultrasonograph examination were consistent with extrahepatic portosystemic shunts, resulting in hepatic encephalopathy. When surgical correction proved not to be a viable option, the dog was euthanized. Postmortem examination revealed multiple shunts likely acquired after severe hepatitis.     

Acromegaly due to a somatroph adenoma in a dog

A 10-year-old uncastrated male Dalmatian dog was referred for gait abnormalities consisting of chronic progressive stiffness and rigidity. Other symptoms were polyphagia associated with weight gain, polyuria and polydipsia, excessive panting, and an inspiratory stridor. The owner had noticed progressive thickening of the skin and enlargement of the tongue over the last 3 years. Physical examination revealed thickening of the skin, redundant skin folds, and enlargement of the tongue. The only remarkable abnormalities found on routine laboratory examination were mild anaemia and an increased serum fructosamine concentration. Circulating concentrations of total thyroxine, free thyroxine, and cTSH, and the results of an ACTH stimulation test were all within reference ranges. The basal serum growth hormone (GH) concentration was markedly elevated (23microg/l) and did not decrease during a glucose tolerance test or after somatostatin administration. The serum insulin-like growth factor-1 concentration was also markedly elevated (1254microg/l). Basal serum insulin concentration was high (95mU/l) and insulin concentrations increased considerably after glucose loading, consistent with insulin resistance. Abdominal ultrasonography showed no abnormalities. Survey radiographs of the vertebral column showed severe spondylosis deformans extending from the cervical to the lumbosacral spine. CT scanning of the skull showed an enlarged pituitary gland with normal enhancement pattern. On post-mortem examination, the entire vertebral column appeared as a single and inflexible structure due to the presence of multiple fused osteophytes. The pituitary gland contained an acidophilic adenoma that immunostained positively for GH (and negatively for ACTH and alpha-MSH). In conclusion, this Dalmatian dog with acromegaly and insulin resistance represents the first case of GH hypersecretion proven to be due to a somatotroph adenoma.     

Vertebral osteomyelitis due to Nocardia in a dog

Vertebral osteomyelitis in a Kelpie crossbred bitch was diagnosed on clinical and radiological grounds. Nocardia spp was isolated from a sample of the infected bone obtained during surgery. Decompressive surgery was performed in an attempt to relieve the pressure of the infected vertebrae on the spinal cord. The contraindication of the use of corticosteroids is emphasised when dealing with back pain of unknown aetiology.     

Ultrasonographic assessment of hemodynamic changes in the portal vein during surgical attenuation of congenital extrahepatic portosystemic shunts in dogs

OBJECTIVE: To determine portal hemodynamic changes associated with surgical shunt ligation and establish ultrasonographic criteria for determining the optimal degree of shunt narrowing and predicting outcome. DESIGN: Case series. ANIMALS: 17 dogs, each with a single congenital extrahepatic portosystemic shunt. PROCEDURE: Pre- and postligation flow velocities and flow directions were determined by Doppler ultrasonography intraoperatively in the shunt and in the portal vein cranial and caudal to the shunt origin. Outcome was evaluated 1 month after surgery by measuring blood ammonia concentration and performing abdominal ultrasonography. RESULTS: Hepatofugal flow was detected in 9 of 17 dogs before shunt attenuation in the portal segment that was between the shunt origin and the entering point of the gastroduodenal vein. If hepatofugal flow became hepatopetal after shunt ligation, hyperammonemia resolved. Hepatofugal portal flow was caused by blood that flowed from the gastroduodenal vein toward the shunt. Shunt attenuation converted hepatofugal flow to hepatopetal in the shunt in 12 of 17 dogs. Chronic portal hypertension developed or perioperative death occurred when the portal congestion index caudal to the shunt origin increased by > 3.6 times. CONCLUSIONS AND CLINICAL RELEVANCE: After hepatopetal flow in the cranial portal vein and the shunt is established, further shunt narrowing is contraindicated. Increase of the portal congestion index caudal to the shunt > 3.5 times should be avoided. Poor outcome because of severe hypoplasia of the portal branches can be expected if the flow direction remains hepatofugal after shunt occlusion cranial to the shunt origin.     

Pancreatic pseudocyst causing extrahepatic biliary obstruction in a dog

A 3-year-old Rhodesian Ridgeback was examined because of recurrent pancreatitis of 2 months duration. The dog had signs of abdominal pain and jaundice. Blood biochemical findings were consistent with extrahepatic bile duct obstruction, but on abdominal ultrasonography no cause of obstruction was identified. At surgery a pancreatic pseudocyst was found in the body of the pancreas. Cystoduodenostomy, cystic omentalisation and biliary diversion resulted in excellent long-term recovery.     

Thrombosis of the portal vein in a miniature schnauzer

A miniature schnauzer with a history of apathy, anorexia and jaundice was presented to the Utrecht University Clinic for Companion Animals. Abnormal laboratory findings included highly increased levels of total bile acids and alkaline phosphatase, and hyponatraemia. Abdominal ultrasonography revealed that the right side of the liver was enlarged and the left side was small, together with a thrombus in the portal vein. Biopsies from the right side of the liver demonstrated subacute to chronic active hepatitis, for which the dog was treated with prednisolone (1 mg/kg/day for four weeks). No improvement was observed and the owner requested euthanasia. At necropsy the left lobes of the liver were found to be small and firm, while the right lobes were large and soft. There were two thrombi in the portal vein. Microscopic examination revealed chronic active hepatitis and cirrhosis.     

Essential hypertension in a dog

Severe hypertension was diagnosed in a dog that initially was referred for evaluation of visual deficits and retinal hemorrhage and eventually was donated for medical treatment of hypertension. Initial blood pressure measured by direct methods was markedly high (systolic, 275 mm of Hg; diastolic, 170 mm of Hg). Measures of renal function were within normal limits, with the exception of hypotonic urine. A test protocol was designed to exclude possible secondary causes of hypertension; negative results of such tests allowed the diagnosis of essential hypertension. The consistency of the hypertension and its response to medical control were studied for 5 years. Blood pressure while the dog was untreated during those years was 240 +/- 24 mm of Hg (systolic) and 146 +/- 14 mm of Hg (diastolic). Plasma renin activity was within normal limits, and the response of the renin-angiotensin system to varied salt intake was normal. The most effective medications used to lower blood pressure were propranolol and captopril, both of which were more effective than salt restriction alone. Five years after the diagnosis of hypertension, the dog was euthanatized because of chronic renal failure secondary to pyelonephritis. Hypertension was less severe as the condition progressed into chronic renal failure. Complete necropsy did not reveal an obvious cause of the hypertension, and histopathologic changes were limited to the cardiovascular system, eyes, and kidneys.     

Intraoperative contrast echocardiography to verify the surgical occlusion of a single extrahepatic portosystemic shunt in a dog

This report details a bubble echocardiographic study carried out during the surgical treatment of a congenital single extrahepatic portosystemic shunt (PSS) in a Labrador Retriever. After celiotomy, agitated saline was injected through a jejunal vein and microbubbles appeared rapidly in the right cardiac chambers. The test confirmed the presence of a PSS, helping the surgeon to identify the vessel concerned and to rule out a second shunt. Successively, portography confirmed what the exploratory celiotomy had revealed before with the aid of the bubble study: a single shunt was located between the portal vein and the right renal vein. It was completely ligated, as all the criteria for this solution were met. Intraoperative contrast echocardiography (ICE) was easy to perform, helpful and undemanding. It is proposed here as an intraoperative ancillary test to diagnose all PSS and to confirm successful treatment when complete shunt closure is possible.     

Exophthalmos due to a wooden foreign body in a dog

An 8-year-old Golden Retriever dog was presented with a 10-month history of right-sided exophthalmos. Radiographs and CT demonstrated a linear density, suggestive of a foreign body, in the region of the ramus of the right mandible. A 7 cm stick, located medial to the right zygomatic arch, was removed during exploratory surgery. The dog recovered with the aid of antibiotics, however was left with a residual facial nerve paralysis.