INTRAVENOUS UROGRAPHY IN THE KOALA (Phascolarctos cinereus)

Urograms were performed on 16 adult koalas to evaluate this procedure for use in the koala. Because there is only small amount of intraabdominal fat, radiographs of the abdomen of koalas lack detail. Contrast medium was excreted more slowly in the koala than in the dog and there was considerable variation in the rate of excretion between koalas. The results of this study indicated that urography was valuable technique for assessing renal anatomy, but there was considerable variation in the time for excretion of the contrast medium.     

DOPPLER MEASUREMENT OF HEPATIC ARTERIAL FLOW IN DOGS: TECHNIQUE AND PRELIMINARY FINDINGS

The common hepatic artery in 10 healthy adult beagles, 20 healthy pups (13 Deerhounds and seven Irish Wolfhounds), and seven dogs with either a congenital or acquired hepatic disorder was examined by duplex-Doppler ultrasonography. Peak systolic velocity (Vs), resistive index (RI), pulse rate, angle of insonation, and sample volume depth were recorded. Measurements in Beagles were made after a 24 h fast and repeated 2 h after feeding. The mean Vs and RI in fasted Beagles were 1.5 m/s (range 1.1-2.3 m/s) and 0.68 (range 0.62-0.74), respectively. Postprandially, there were no significant differences in any of these variables. Mean Vs and RI were lower in pups: 1.0 m/s (range 0.8-1.3 m/s) and 0.59 (range 0.46-0.65), respectively (P < .001). Two dogs with congenital arterioportal fistula had higher mean Vs (P < .001) and lower mean RI (P < .05) than normal pups. No significant differences were detected between normal Beagles, three dogs with portal vein thrombosis, and two dogs with acquired hepatic insufficiency. Differences in measured hepatic blood flow in dogs of different age or breed will complicate diagnostic use of hepatic arterial Doppler measurements.     

Combined Omental Pedicle Grafts and Thoracodorsal Axial Pattern Flaps for the Reconstruction of Chronic, Nonhealing Axillary Wounds in Cats

OBJECTIVE: To assess the results of an omental pedicle graft in combination with a thoracodorsal axial pattern flap for the reconstruction of chronic nonhealing axillary wounds in 10 cats caused by forelimb entrapment within a collar. STUDY DESIGN: A prospective, clinical trial. ANIMALS USED: Ten client-owned domestic shorthair cats. METHODS: Routine biochemical and hematologic evaluation was performed on each cat, and all were tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV). Microbial culture was performed on samples from the wounds. After surgical debridement, omentalization using a vascular pedicle of greater omentum, and closure of the chronic axillary wounds, using a thoracodorsal axial pattern flap, was performed. All excised tissue was examined histologically. RESULTS: The sex distribution was 7 males and 3 females, with a mean age of 3.5 years. The cats had undergone a median number of 3 previous repair attempts over a 1.5- to 25-month period before referral (mean, 10.2 months). No hematologic or biochemical abnormalities were noted apart from moderately elevated creatine kinase and aspartate transaminase concentrations in some cats. All cats were negative for FIV and FeLV. Histologic examination of resected tissue revealed hair (foreign body) in 2 cats and an unidentified foreign-body reaction in 3 other cats. Complete healing occurred in all cats (mean follow-up period of 21.7 months), with 2 cats requiring further surgery: 1 for flap dehiscence at 4 days after surgery, and 1 for donor-site dehiscence at 4 days after surgery. One other cat developed a large seroma in the axilla that resolved by 10 days following surgery. CONCLUSION: The use of an omental pedicle graft in combination with a thoracodorsal axial pattern flap is the first consistently successful 1-step technique for the management of chronic nonhealing axillary wounds in cats.     

A Method for Controlling Portal Pressure After Attenuation of Intrahepatic Portacaval Shunts

Two dogs had right divisional intrahepatic portacaval shunts within the right lateral lobe of the liver. In both dogs, an extrahepatic portacaval vascular anastomosis was created, using an autologous right external jugular vein graft. The intrahepatic shunts were completely attenuated using a prehepatic intravascular caval approach. The creation of the vascular graft allowed postattenuation rises in portal pressure to be controlled, preventing the development of life threatening portal hypertension. Both dogs recovered from the procedure. One dog is clinically normal and does not require medication (8 months postoperatively); the other dog was euthanatized 5 months after surgery because of renal failure. Scintigraphy studies, performed before surgery, showed significant shunting of portal blood away from the liver (shunt indices 65% and 59%), whereas, similar studies done 4 weeks afterwards showed almost normal portal blood flow (shunt indices 16% and 18%, respectively).     

DISTINGUISHING RHINITIS AND NASAL NEOPLASIA BY RADIOGRAPHY

To compare the incidence of radiographic signs in dogs with rhinitis and primary nasal neoplasia and to assess the performance of observers for distinguishing these conditions, the nasal radiographs of 72 dogs with either rhinitis (n = 42) or primary nasal neoplasia (n = 30) were examined by two independent observers using custom-designed forms to record their interpretations. Rhinitis was associated with a higher incidence of focal or multifocal lesions, localised soft tissue opacities, lucent foci, and a lack of frontal sinus involvement. Neoplasia was associated with soft tissue opacities and loss of turbinate detail that affected the entire ipsilateral nasal cavity, signs of invasion of the bones surrounding the nasal cavity, and soft tissue/fluid opacities within the ipsilateral frontal sinus. The signs with the highest positive predictive value (PPV) for rhinitis were absence of frontal sinus lesions and lucent foci in nasal cavity (PPV of each 82%), and invasion of surrounding bones for neoplasia (PPV 88%). There were no significant differences in the position of the lesion within the nasal cavity, incidence of unilateral versus bilateral lesions, calcified lesions, or absence of teeth. There was moderate agreement between observers about the diagnosis (kappa 0.59). Areas (SE) under ROC curves were 0.94 (0.03) and 0.96 (0.03) for observers A and B, respectively (not significantly different; P = 0.68). These results indicate a high accuracy for radiologists examining dogs with nasal diseases. Differentiation of rhinitis and nasal neoplasia should be based on finding combinations of radiologic signs that together have a high PPV. Differences in interpretation between experienced observers in this study suggest that certain signs are potential sources of error.     

HYDROMYELIA IN THE DOG

Hydromyelia is a dilation of the spinal cord central canal. In man this may be due to congenital malformations such as Dandy-Walker syndrome and Chiari malformations or may be acquired as result of infection, trauma or neoplasia. In dogs hydromyelia may be accidentally diagnosed during routine cisterna magna myelography. Hydromyelia, and its possible etiology, may be confirmed by means of computed tomography or magnetic resonance imaging. Three dogs with hydromyelia due to differing etiologies are described.     

ULTRASONOGRAPHIC DIAGNOSIS OF PORTAL VEIN THROMBOSIS IN FOUR DOGS

Ante mortem diagnosis of portal vein thrombosis was determined ultrasonographically in four dogs. In each dog the thrombus was visible in two-dimensional, grey-scale images of the portal vein obtained through a right intercostal window. Duplex-Doppler measurements and color-Doppler images provided information about the effects of thrombosis on portal blood flow. Reduced portal blood flow compatible with portal hypertension was detected in three dogs. A hypercoagulable state was probably involved in the pathogenesis of portal vein thrombosis in two dogs, one with pancreatitis and gastrointestinal blood loss and another with protein-losing nephropathy and probable immune-mediated anemia. The third dog had chronic ehrlichiosis; thrombosis was probably secondary to vasculitis. The remaining dog had thrombosis secondary to invasion of the portal vein by a recurrent duodenal neoplasm. This dog was euthanized because the tumor was considered inoperable. The dog with pancreatitis developed acute portal hypertension due to obstruction of the portal vein by the thrombus and was euthanized. The dogs with protein-losing nephropathy and ehrlichiosis were treated medically and recovered. Although portal vein thrombosis is uncommon, this complication should be considered in dogs with a variety of abdominal or systemic disorders. Ultrasonography is a practical method for diagnosis of portal vein thrombosis and detection of the underlying cause.