Development and validation of a multivariable model and online decision-support calculator to aid in preoperative discrimination of benign from malignant splenic masses in dogs.

OBJECTIVE: To develop a multivariable model and online decision-support calculator to aid in preoperative discrimination of benign from malignant splenic masses in dogs. ANIMALS: 522 dogs that underwent splenectomy because of splenic masses. PROCEDURES: A multivariable model was developed with preoperative clinical data obtained retrospectively from the records of 422 dogs that underwent splenectomy. Inclusion criteria were the availability of complete abdominal ultrasonographic examination images and splenic histologic slides or histology reports for review. Variables considered potentially predictive of splenic malignancy were analyzed. A receiver operating characteristic curve was created for the final multivariable model, and area under the curve was calculated. The model was externally validated with data from 100 dogs that underwent splenectomy subsequent to model development and was used to create an online calculator to estimate probability of splenic malignancy in individual dogs. RESULTS: The final multivariable model contained 8 clinical variables used to estimate splenic malignancy probability: serum total protein concentration, presence (vs absence) of ≥ 2 nRBCs/100 WBCs, ultrasonographically assessed splenic mass diameter, number of liver nodules (0, 1, or ≥ 2), presence (vs absence) of multiple splenic masses or nodules, moderate to marked splenic mass inhomogeneity, moderate to marked abdominal effusion, and mesenteric, omental, or peritoneal nodules. Areas under the receiver operating characteristic curves for the development and validation populations were 0.80 and 0.78, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The online calculator (T-STAT.net or T-STAT.org) developed in this study can be used as an aid to estimate the probability of malignancy in dogs with splenic masses and has potential to facilitate owners' decisions regarding splenectomy.

Survival time of dogs with splenic hemangiosarcoma treated by splenectomy with or without adjuvant chemotherapy: 208 cases (2001-2012).

OBJECTIVE: To determine survival time for dogs with splenic hemangiosarcoma treated with splenectomy alone, identify potential prognostic factors, and evaluate the efficacy of adjuvant chemotherapy. DESIGN: Retrospective case series. ANIMALS: 208 dogs. PROCEDURES: Medical records were reviewed, long-term follow-up information was obtained, and survival data were analyzed statistically. RESULTS: 154 dogs were treated with surgery alone, and 54 were treated with surgery and chemotherapy. Twenty-eight dogs received conventional chemotherapy, 13 received cyclophosphamide-based metronomic chemotherapy, and 13 received both conventional and metronomic chemotherapy. Median survival time of dogs treated with splenectomy alone was 1.6 months. Clinical stage was the only prognostic factor significantly associated with survival time. When the entire follow-up period was considered, there was no significant difference in survival time between dogs treated with surgery alone and dogs treated with surgery and chemotherapy. However, during the first 4 months of follow-up, after adjusting for the effects of clinical stage, survival time was significantly prolonged among dogs receiving any type of chemotherapy (hazard ratio, 0.6) and among dogs receiving both conventional and metronomic chemotherapy (hazard ratio, 0.4). CONCLUSIONS AND CLINICAL RELEVANCE: Clinical stage was strongly associated with prognosis for dogs with splenic hemangiosarcoma. Chemotherapy was effective in prolonging survival time during the early portion of the follow-up period. Combinations of doxorubicin-based conventional protocols and cyclophosphamide-based metronomic protocols appeared to be more effective than either type of chemotherapy alone, but prolongations in survival time resulting from current protocols were modest.

Risk factors for perioperative death in dogs undergoing splenectomy for splenic masses: 539 cases (2001-2012).

OBJECTIVE: To determine the perioperative mortality rate, causes of death, and risk factors for perioperative death in dogs undergoing splenectomy for splenic mass lesions. DESIGN: Retrospective case series. ANIMALS: 539 dogs. PROCEDURES: Medical records of dogs that underwent splenectomy for known splenic masses were reviewed. Perioperative mortality rate and causes of death were determined. Associations between potential prognostic factors and perioperative death were evaluated by multivariable logistic regression analysis. RESULTS: 41 of 539 (7.6%) dogs died during the perioperative period. Thrombotic and coagulopathic syndromes and uncontrolled bleeding from metastatic lesions were the most common causes of death. Of the variables selected for multivariable analysis, platelet count at admission, whether PCV at admission was < 30%, and development of ventricular arrhythmias during surgery were significantly associated with outcome. For each decrease in platelet count of 10,000 platelets/µL, odds of death increased by approximately 6%. For dogs with PCV < 30%, odds of death were approximately twice those for dogs with PCV ≥ 30%, and for dogs that developed intraoperative arrhythmias, odds of death were approximately twice those for dogs that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Marked preoperative thrombocytopenia or anemia and development of intraoperative ventricular arrhythmias were identified as risk factors for perioperative death in dogs with splenic masses. The risk of death may be limited by efforts to prevent thrombotic and coagulopathic syndromes and to control all sources of intra-abdominal hemorrhage.

Medium and long term evaluation of sliding humeral osteotomy in dogs.

OBJECTIVE: To evaluate medium and long term effects of sliding humeral osteotomy (SHO) in dogs. STUDY DESIGN: Prospective study. ANIMALS: Dogs (n = 32). METHODS: Data (2008-2010) collected from medical records included force plate data, radiographs, and a 15 question owner survey of dog soundness before SHO and at final evaluation. RESULTS: All dogs except 2 exceeded their preoperative ground reaction forces in the operated limb and there was a statistically significant upward trend in ground reaction forces compared with the contralateral limb. Radiographic osteophytosis using the IEWG protocol had not progressed on the operated limb except in 1 dog. Most (90%) owners felt that lameness had diminished at the final evaluation compared with preoperative lameness. Ten dogs had postoperative complications; 6 were considered major, requiring further surgery. CONCLUSIONS: SHO can be performed successfully in dogs to limit the radiographic progression of osteophytosis and increase use of the affected limb; however, the complication rate is high and further implant or technique modifications are needed to improve results.