Survival time for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone: the Canine Lymphoma Steroid Only trial.

OBJECTIVE: To evaluate survival times for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone. ANIMALS: 109 client-owned dogs recruited from 15 institutions in the United States. PROCEDURES: Dogs were treated with prednisone at a dosage of 40 mg/m2, PO, once daily for 7 days and at a dosage of 20 mg/m2, PO, once daily thereafter. Quality of life (QOL) was assessed by owners with a visual analog scale when treatment was started (day 0), 1 and 2 weeks after treatment was started, and every 4 weeks thereafter. The primary outcome of interest was survival time as determined by the Kaplan-Meier method. Factors potentially associated with survival time were examined. RESULTS: Median overall survival time was 50 days (95% CI, 41 to 59 days). Factors associated with survival time included substage (a vs b) and immunophenotype (B cell vs T cell). Owner-assigned QOL scores on days 0 and 14 were significantly positively correlated with survival time. When QOL score was dichotomized, dogs with day 0 or day 14 QOL scores ≥ 50 had significantly longer survival times, compared with dogs with day 0 or day 14 QOL scores < 50. No variables were predictive of long-term (> 120 days) survival. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that survival times were short for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone. Owner-perceived QOL and clinician-assigned substage were both associated with survival time. Findings provide potentially important information for clinicians to discuss with owners of dogs with lymphoma at the time treatment decisions are made.

Tolerability of lomustine in combination with cyclophosphamide in dogs with lymphoma.

This retrospective study describes toxicity associated with a protocol of lomustine (CCNU) and cyclophosphamide (CTX) in dogs with lymphoma. CCNU was administered per os (PO) at a targeted dosage of 60 mg/m(2) body surface area on day 0, CTX was administered PO at a targeted dosage of 250 mg/m(2) divided over days 0 through 4, and all dogs received prophylactic antibiotics. Ninety treatments were given to the 57 dogs included in the study. Neutropenia was the principal toxic effect, and the overall frequency of grade 4 neutropenia after the first treatment of CCNU/CTX was 30% (95% confidence interval, 19-43%). The mean body weight of dogs with grade 4 neutropenia (19.7 kg ± 13.4 kg) was significantly less than the mean body weight of dogs that did not develop grade 4 neutropenia (31.7 kg ± 12.4 kg; P = .005). One dog (3%) developed hematologic changes suggestive of hepatotoxicity. No dogs had evidence of either renal toxicity or hemorrhagic cystitis. Adverse gastrointestinal effects were uncommon. On the basis of the findings reported herein, a dose of 60 mg/m(2) of CCNU combined with 250 mg/m(2) of CTX (divided over 5 days) q 4 wk is tolerable in tumor-bearing dogs.

Cross-sectional study to investigate the association between vitamin D status and cutaneous mast cell tumours in Labrador retrievers.

Epidemiological data indicate that low serum vitamin D concentrations are associated with an increased risk of a variety of human tumours. Cutaneous mast cell tumours (MCT) occur more frequently in dogs than in any other species. Canine MCT express the vitamin D receptor, and vitamin D derivatives have in vitro and in vivo anti-tumour activity. We sought to examine the association between vitamin D serum level and MCT in Labrador retrievers, a dog breed predisposed to MCT development. To examine this association, serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations were examined in eighty-seven Labrador retrievers, including thirty-three with MCT and fifty-four unaffected controls. The relationship between cases and controls and 25(OH)D3 level, age and body condition score were evaluated using univariate and multivariate analyses. Potential differences in vitamin D oral intake, calculated on the basis of a dietary questionnaire, were also evaluated between groups. Mean 25(OH)D3 concentration (104 (SD 30) nmol/l) in dogs with MCT was significantly lower than that of unaffected dogs (120 (SD 35) nmol/l; P = 0.027). The mean calculated vitamin D intake per kg body weight in Labrador retrievers with MCT was not statistically different from that of unaffected Labrador retrievers (0.38 (SD 0.25) and 0.31 (SD 0.22) µg/kg body weight, respectively; P = 0.13). These findings suggest that low levels of 25(OH)D3 might be a risk factor for MCT in Labrador retrievers. Prospective cohort studies are warranted.