Temporal changes in characteristics of injection-site sarcomas in cats: 392 cases (1990-2006).

OBJECTIVE: To evaluate changes in characteristics of feline injection-site sarcomas (ISSs) from 1990 through 2006. DESIGN: Retrospective case series. ANIMALS: 392 cats with a histologic diagnosis of soft tissue sarcoma, osteosarcoma, or chondrosarcoma at potential injection sites. PROCEDURES: Classification and anatomic location of tumors and signalment of affected cats were compared between ISSs diagnosed before and after publication of the Vaccine Associated Feline Sarcoma Task Force vaccination recommendations in 1996. RESULTS: From before to after publication of the vaccination recommendations, proportions of ISSs significantly decreased in the interscapular (53.4% to 39.5%) and right and left thoracic (10.2% to 3.6% and 9.1% to 1.3%, respectively) regions. On the other hand, proportions of ISSs significantly increased in the right thoracic limb (1.1% to 9.5%) and the combined regions of the right pelvic limb with right lateral aspect of the abdomen (12.5% to 25.0%) and the left pelvic limb with left lateral aspect of the abdomen (11.4% to 13.8%). Patterns of tumor classification and signalment did not change. CONCLUSIONS AND CLINICAL RELEVANCE: Despite publication of the vaccination recommendations, a high proportion of tumors still developed in the interscapular region. There was also an increase in lateral abdominal ISSs, which are more difficult to treat and are likely attributable to aberrant placement of injections intended for the pelvic limbs. Veterinarians are complying with vaccination recommendations to some extent, but they need to focus on administering vaccines as distally as possible on a limb to allow for complete surgical margins if amputation of a limb is required.

Evaluation of strontium Sr 90 for the treatment of superficial squamous cell carcinoma of the nasal planum in cats: 49 cases (1990-2006).

OBJECTIVE: To determine progression-free and overall survival times of cats with squamous cell carcinoma (SCC) of the nasal planum following treatment with a single fraction of strontium Sr 90 ((90)Sr). DESIGN: Retrospective case series. ANIMALS: 49 cats with SCC of the nasal planum. PROCEDURES: Information including FIV infection status, diagnosis of SCC vs SCC in situ (ie, evidence that the tumor did or did not penetrate the epidermal basement membrane, respectively), (90)Sr dose and number of probe applications, treatment-related response and complications, and recurrence of SCC and new lesion development was obtained from medical records. The relationships of these variables with calculated progression-free and overall survival times were assessed. RESULTS: Of 49 cats that underwent (90)Sr plesiotherapy (median dose, 128 Gy), 48 (98%) had a response to treatment and 43 (88%) had a complete response. Median progression-free and overall survival times were 1,710 and 3,076 days, respectively. Treatment complications were infrequent (4 [8%] cats) and mild. Following treatment, the SCC recurrence rate was 20% (10/49 cats); 16 (33%) cats developed new lesions in other locations. Overall survival time was significantly longer for cats with a complete response to treatment than for those with a partial response. None of the other variables evaluated had a significant effect on progression-free or overall survival time. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment of cats with SCC of the nasal planum with a single fraction of (90)Sr appeared to be effective and well tolerated. Initial response to treatment was predictive of overall survival time.

Diagnosis and treatment of zinc poisoning in a dog.

Acute zinc poisoning has been observed in dogs following the ingestion of metallic zinc objects. A 1 1/2-y-old female miniature bull terrier exhibiting anorexia, vomiting, depression, fever (39.9 C), icterus and intravascular hemolysis was diagnosed with acute zinc poisoning. Anemia, Heinz body production, azotemia and bilirubinemia were also evident. Abnormal pancreatic, hepatic and renal functions were also apparent. A radio opaque object was observed in the stomach. Based upon an elevated plasma zinc level of 28.6 ppm, a tentative diagnosis of zinc poisoning was made. Following surgical removal of the metallic zinc object, a blood transfusion and fluid therapy were given to restore the normal blood volume. Heparin, Cephazolin and Raniditine were also given, although chelation therapy was not provided. Zinc levels in the plasma declined in a steady fashion (half-life = 7.6 d). Complications, such as disseminated intravascular coagulation, chronic pancreatitis, renal or hepatic failure, were not observed. By 20 d post surgery, only mild elevation of liver enzymes was evident. Measurements of the half-life of zinc may provide a useful indication of prognosis and the success of treatment.