This retrospective case series evaluates the outcome of 21 dogs with grade II stage 2 mast cell tumour (MCT) treated with adequate local therapy and adjuvant systemic chemotherapy (prednisone, vinblastine and CCNU). The median survival for all dogs was 1359 days (range, 188–2340). Median disease-free interval was 2120 days (149–2325 days). Dogs treated with surgery and chemotherapy had shorter survival (median, 1103 days; 188–2010 days) than those that underwent surgery, radiation therapy and chemotherapy as part of their treatment (median, 2056 days; 300–2340 days). Two patients had local recurrence in the radiation field and four patients had de novo MCT. Distant metastasis was not observed in any dogs. The results of this study suggest that, in the presence of loco-regional lymph node metastasis in grade II MCT, the use of prednisone, vinblastine and CCNU after adequate local-regional therapy can provide a median survival in excess of 40 months.

Bone metastases were not identified in any dog with whole body CT. Thoracic and abdominal CT detected lung lesions and concurrent neoplasia in dogs with primary appendicular osteosarcoma. Whole body CT may be a useful adjunct to other screening tests for disseminated malignancy.

Diagnosis of gastric tumors in dogs is difficult and is often obtained by biopsy following identification of a mass through ultrasound (US) or endoscopy. In human medicine, modalities such as CT and endoscopy are standard of care in the diagnosis and staging of gastric tumors. Although one veterinary study has described CT findings of gastric tumors in dogs using iatrogenic gas dilation, there are no veterinary studies that have directly compared the usefulness of US versus CT in the diagnosis and staging of these tumors. This retrospective, descriptive study evaluated US and CT images from 13 dogs. Gastric tumor diagnoses included leiomyoma (n = 4), adenocarcinoma (n = 3), leiomyosarcoma (n = 3), gastrointestinal stromal tumor (n = 2), and lymphoma (n = 1). Computed tomography was successful in identification of 92% of gastric tumors, while US identified only 69%. Computed tomography identified more locations of lymphadenopathy and correctly identified the location of gastric tumors more frequently than US when compared to the surgical, endoscopic, or necropsy reports. Most features seen on US and CT overlapped between the different tumor types. Lymphoma had a lower mean attenuation in CT than the other gastric tumors and was the only gastric tumor to not have complete loss of the gastric wall layering on US. As expected, adenocarcinoma appeared as gastric wall thickening with regional lymphadenopathy.Findings supported using CT as an ancillary diagnostic test for characterizing and staging gastric tumors in dogs and assisting in the selection of surgical candidates. K E Y W O R D Sadvanced cross sectional imaging, canine, neoplasia, stomach INTRODUCTIONGastric tumors are rare in dogs, accounting for less than 1% of all neoplasms diagnosed. 1 The most common gastric tumor in dogs is adenocarcinoma, but tumors such as lymphoma, leiomyosarcoma, leiomyoma, extramedullary plasmacytoma, fibrosarcoma, gastroin-ABBREVIATIONS: GIST, gastrointestinal stromal tumor; US, ultrasound Previous publication or presentation disclosure: Presented in poster format at the 2019 National Veterinary Scholars Symposium in Worcester, MA EQUATOR network disclosure: EQUATOR network checklist was not used. testinal stromal tumor (GIST), mast cell tumor, and polyps are also reported. 2-4 Diagnosis is difficult and often occurs late in the disease process, making prognosis poor due to the likelihood of metastases. At this point of time, no clear consensus in veterinary medicine has been provided in regard to the selection of CT over ultrasound (US) in the detection and staging of patients with gastric neoplasia, especially if surgery is being considered. Delineating what diagnostic test is of value and highlighting limitations of modalities may help the radiologist and clinician to make better recommendations for their patients.Abdominal US and endoscopy have been the imaging modalities of

Stereotactic radiation therapy (SRT) has emerged as a convenient definitive treatment modality in veterinary medicine, but few studies exist evaluating outcome with treatment for canine nasal tumors, and no studies report the treatment of one single tumor histotype. This retrospective, observational study evaluates toxicity, response, and survival in 17 dogs with nasal carcinomas treated with SRT. Dogs received a median of 3000 centigray in three fractions via 6-MV linear accelerator. Eighty-eight percent of patients (n = 15) demonstrated clinical benefit. Of dogs with repeated CT imaging (n = 10), 60% (n = 6) achieved a partial response and 10% (n = 1) achieved a complete response. Median progression-free survival (PFS) was 359 days. Median survival time (MST) was 563 days. Among dogs evaluable for acute toxicity, 50% (n = 10) developed low grade toxicity (grade 1, n = 4; grade 2, n = 1). No patients developed grade 3 toxicity. 16 dogs (87%) evaluable over the long term developed signs consistent with possible late toxicity. The majority of late toxicities were mild (alopecia, hyperpigmentation, and leukotrichia n = 10; ocular discharge and keratoconjunctivitis sicca n = 5). Thirty-seven percent of patients (n = 6) developed seven possible grade 3 late toxicities (blindness, n = 3; fistula, n = 1; seizures, n = 3), which were difficult to distinguish from progressive disease in most patients. Of the prognostic factors evaluated (demographics, tumor stage, dosimetric data, epistaxis, facial deformity, clinical response, image-based response, nonsteroidal anti-inflammatory drugs, and chemotherapy), only clinical response was a positive prognostic factor on MST (P < .00). No factors were found to be significantly associated with PFS.