Septic Peritonitis Secondary to Neoplasia in Two Canine Cancer-Bearing Patients Lacking Gastrointestinal and Hepatic Organ Rupture.

In this case report, we describe the presentation, diagnosis, and outcome of septic peritonitis secondary to neoplasia in patients lacking evidence of gastrointestinal content leakage, liver abscessation, or other treatment-associated risk factors. Two dogs presented with a diagnosis of neoplasia and nonspecific clinical signs such as lethargy, hyporexia, vomiting, and discomfort that was localized to the abdomen. The diagnoses at presentation consisted of a perianal tumor consistent with apocrine gland anal sac adenocarcinoma and systemic mastocytosis. Neither of the dogs was considered systemically immunocompromised or had received recent cytotoxic chemotherapy treatment or surgical procedures. A common finding on blood work in the two dogs was the presence of band neutrophils. The diagnosis of septic peritonitis via fluid analysis and cytology was delayed in both cases. No treatment for the supposed underlying cause of septic peritonitis was pursued and euthanasia was pursued in both cases owing to poor prognosis. On necropsy, one dog was suspected to have developed septic peritonitis because of an abscessed lymph node, and in the other case, no definitive source was identified. Septic peritonitis can arise secondary to neoplasia that is not primarily involving the liver or gastrointestinal tract in canine patients that lack treatment-associated risk factors.

McKesson® lubricating jelly and Aquasonic® ultrasound gel can be used as bolus materials for radiation therapy.

Bolus materials are commonly used for both human and veterinary radiation therapy (RT). Commercially available bolus materials often leave an air gap between the bolus and the skin which can lead to underdosing of the tumor. This prospective exploratory study evaluated the 6 MV X-ray and electron beam (6, 9, and 12 MeV) attenuating properties for two alternative bolus materials: McKesson lubricating jelly® (MLJ) and Aquasonic 100 Ultrasound gel® (AUG). The results comparing MLJ and water for 12 MeV and 9 MeV electron beams showed <3% difference, however, no other significant differences in radiation dose between water and MLJ nor AUG were seen. Findings demonstrated that both AUG and MLJ have radiation dose attenuating properties similar to water and supported use of these materials as alternative bolus materials for veterinary radiation therapy applications.

Canine salivary gland carcinoma treated with stereotactic body radiation therapy: a retrospective case series.

Objective: The aim of this study was to describe the therapeutic outcomes of dogs with locally advanced salivary gland carcinomas (SGC) following stereotactic body radiation therapy (SBRT). Methods: A single institution retrospective study was conducted of client-owned dogs with macroscopic SGC treated with SBRT. Patient signalment, clinical characteristics, and treatment parameters were recorded. Clinical benefit was determined based on follow-up physical examination and medical history. Progression-free interval (PFI), median survival time (MST), and disease-specific survival (DSS) were calculated using Kaplan-Meier analysis. Acute and late toxicity were recorded according to Veterinary Radiation Therapy Oncology Group (VRTOG) criteria. Results: Six patients were included in the study. Tumor origins were mandibular (n = 3), parotid (n = 2), and zygomatic (n = 1) salivary glands. The SBRT prescription was 10 Gy × 3 daily or every other day. All patients (100%) experienced clinical benefit from treatment at a median time of 34 days (range 28-214). No local or regional nodal failure was reported following SBRT. Progressive pulmonary metastatic disease was documented in three dogs (50%). The median PFI was 260 days (range 43-1,014) and the MST was 397 days (range 185-1,014). Median DSS was 636 days (range 185-1,014). Four dogs (66.6%) died of confirmed or suspected metastatic SGC. The reported acute side effects included grade 2 mucositis (n = 1) and vision loss (n = 1). No late side effects were recorded. Conclusion: This study suggests that SBRT may provide durable local control for invasive SGC in dogs. Further investigation in a larger cohort of patients is warranted. The incidence of reported acute and late toxicity was low.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.