Use of transsplenic injection of agitated saline and heparinized blood for the ultrasonographic diagnosis of macroscopic portosystemic shunts in dogs.

We describe the use of ultrasonography-guided percutaneous splenic injection of agitated saline and heparinized blood for the diagnosis of portosystemic shunts (PSS) in 34 dogs. Agitated saline mixed with 1 ml of heparinized autologous blood was injected into the spleen of 34 sedated dogs under sonographic guidance. The transducer was then sequentially repositioned to visualize the portal vein, the caudal vena cava, and the right atrium through different acoustic windows. It was possible to differentiate between intrahepatic and extrahepatic shunts depending on the entry point of the microbubbles into the caudal vena cava. Portoazygos shunts and portocaval shunts could be differentiated based on the presence of microbubbles in the caudal vena cava and/or the right atrium. In one dog, collateral circulation due to portal hypertension was identified. In dogs with a single extrahepatic shunt, the microbubbles helped identify the shunting vessel. The technique was also used postoperatively to assess the efficacy of shunt closure. All abnormal vessels were confirmed by exploratory laparotomy or with ultrasonographic identification of the shunting vessel. Ultrasound-guided transsplenic injection of agitated saline with heparinized blood should be considered as a valuable technique for the diagnosis of PSS; it is easy to perform, safe, and the results are easily reproducible.

Multi-center, placebo-controlled, double-blind, randomized study of oral toceranib phosphate (SU11654), a receptor tyrosine kinase inhibitor, for the treatment of dogs with recurrent (either local or distant) mast cell tumor following surgical excision.

PURPOSE: The purpose of this study was to determine the objective response rate (ORR) following treatment of canine mast cell tumors (MCT) with toceranib phosphate (Palladia, SU11654), a kinase inhibitor with both antitumor and antiangiogenic activity through inhibition of KIT, vascular endothelial growth factor receptor 2, and PDGFRbeta. Secondary objectives were to determine biological response rate, time to tumor progression, duration of objective response, health-related quality of life, and safety of Palladia. EXPERIMENTAL DESIGN: Dogs were randomized to receive oral Palladia 3.25 mg/kg or placebo every other day for 6 weeks in the blinded phase. Thereafter, eligible dogs received open-label Palladia. RESULTS: The blinded phase ORR in Palladia-treated dogs (n = 86) was 37.2% (7 complete response, 25 partial response) versus 7.9% (5 partial response) in placebo-treated dogs (n = 63; P = 0.0004). Of 58 dogs that received Palladia following placebo-escape, 41.4% (8 complete response, 16 partial response) experienced objective response. The ORR for all 145 dogs receiving Palladia was 42.8% (21 complete response, 41 partial response); among the 62 responders, the median duration of objective response and time to tumor progression was 12.0 weeks and 18.1 weeks, respectively. Palladia-treated responders scored higher on health-related quality of life versus Palladia-treated nonresponders (P = 0.030). There was no significant difference in the number of dogs with grade 3/4 (of 4) adverse events; adverse events were generally manageable with dose modification and/or supportive care. CONCLUSIONS: Palladia has biological activity against canine MCTs and can be administered on a continuous schedule without need for routine planned treatment breaks. This clinical trial further shows that spontaneous tumors in dogs are good models to evaluate therapeutic index of targeted therapeutics in a clinical setting.

Results of excision of thymoma in cats and dogs: 20 cases (1984-2005).

OBJECTIVE: To provide long-term follow-up information for a series of dogs and cats with invasive and noninvasive thymomas treated by excision alone. DESIGN: Retrospective case series. ANIMALS: 9 cats and 11 dogs with thymoma. PROCEDURES: Medical records were reviewed. The following factors were analyzed for their effect on prognosis: age of dog or cat, invasiveness of the tumor, percentage of lymphocytes in the mass (percentage lymphocyte composition) on histologic evaluation, and mitotic index of the mass. RESULTS: All patients were treated with excision of the tumor alone. Median overall survival time for the cats was 1,825 days, with a 1-year survival rate of 89% and a 3-year survival rate of 74%. Median overall survival time for the dogs was 790 days, with a 1-year survival rate of 64% and a 3-year survival rate of 42%. Recurrence of thymoma was observed in 2 cats and 1 dog, and a second surgery was performed in each, with subsequent survival times of 5, 3, and 4 years following the first surgery. Percentage lymphocyte composition of the mass was the only factor that was significantly correlated with survival time; animals with a high percentage of lymphocytes lived longer. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicated that most cats and dogs with thymomas did well after excision. Even cats and dogs with invasive masses that survived the surgery and the few cats and dogs with recurrent thymomas or paraneoplastic syndromes had a good long-term outcome. Excision should be considered an effective treatment option for dogs and cats with thymomas.