Many new diagnostic in-house tests for identification of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infection have been licensed for use in veterinary practice, and the question of the relative merits of these kits has prompted comparative studies. This study was designed to define the strengths and weaknesses of seven FIV and eight FeLV tests that are commercially available. In this study, 536 serum samples from randomly selected cats were tested. Those samples reacting FIV-positive in at least one of the tests were confirmed by Western blot, and those reacting FeLV-positive were confirmed by virus isolation. In addition, a random selection of samples testing negative in all test systems was re-tested by Western blot (100 samples) and by virus isolation (81 samples). Specificity, sensitivity, positive and negative predictive values of each test and the quality of the results were compared.

Background: Oxidative stress might play a role in carcinogenesis, as well as impacting morbidity and mortality of veterinary cancer patients. The purpose of this study was to evaluate antioxidant concentrations and biomarkers of oxidative stress in dogs with newly diagnosed lymphoma before treatment and once in remission, with comparison with healthy controls.Hypothesis: Dogs with lymphoma have increased oxidant and reduced antioxidant concentrations compared with healthy controls, and that these abnormalities normalize once remission is achieved.Animals: Seventeen dogs with lymphoma and 10 healthy controls. Methods: Prospective, observational study. Measures of oxidative stress [malondialdehyde and total isoprostanes (isoP)] and antioxidants [a-tocopherol, g-tocopherol, oxygen radical absorbance capacity (ORAC), and glutathione peroxidase (GSHPx)] were assessed in dogs with newly diagnosed lymphoma before treatment compared with healthy control dogs. The same parameters were measured in the dogs with lymphoma on week 7 of the chemotherapy protocol when all dogs were in remission.Results: At baseline, dogs with lymphoma had significantly lower a-tocopherol (P o.001) and g-tocopherol (P 5 .003) but higher GSHPx (P 5 .05), ORAC (P 5 .001), and isoP (P o .001) compared with healthy controls. In the dogs with lymphoma, a-tocopherol concentrations were higher (P 5 .005) and ascorbic acid were lower (P 5 .04) after treatment.Conclusions and Clinical Importance: Results suggest that dogs with lymphoma have alterations in oxidant and antioxidant concentrations and that the status of some of these biomarkers normalize after remission. Further studies are warranted to determine whether antioxidant interventions to correct these are beneficial in the treatment of canine lymphoma.

Background: Multidrug resistance is the most common cause of treatment failure in dogs with multicentric lymphoma. 5‐(3,3‐Dimethyl‐1‐triazeno)‐imidazole‐4‐carboxamide (DTIC) is an atypical alkylator used as standard treatment in human Hodgkin's lymphoma, and has been effective in combination treatment to treat resistant lymphoma in dogs. However, no data are available on the use of DTIC as a single agent in the treatment of relapsed canine lymphoma. Hypothesis: Single‐agent DTIC is effective and safe in treating dogs with lymphoma that relapsed or failed to respond to previous chemotherapy. Animals: Forty client‐owned dogs with relapsed lymphoma. Methods: Dogs were eligible for the retrospective study if they had a histologically or cytologically confirmed diagnosis of lymphoma and had relapsed. Dogs received DTIC (800–1,000 mg/m2 every 2–3 weeks as a 4–5‐hour IV infusion) and were evaluated for response rate and duration. Hematologic and gastrointestinal toxicity was assessed. Results: The overall response rate for dogs being treated with DTIC was 35% (14 dogs) with a median progression‐free interval of 43 days. Thirteen dogs had a partial response and 1 dog had a complete response. Stable disease was achieved in 3 dogs. Mild gastrointestinal toxicity was reported in 3 dogs posttreatment. Thrombocytopenia was the principal toxicity observed 7–14 days after the treatment. Treatments were delayed because of thrombocytopenia. Conclusions: DTIC, when used alone, is effective in the treatment of dogs with relapsed lymphoma.

Background: Maitake PETfraction is a standardized essence extracted from the mushroom Maitake (Grifola frondosa) that has antitumor activity in tumor-bearing mice. In addition, PETfraction induces apoptosis in human prostate and bladder cancer cells and suppresses the proliferation in vitro of several canine tumor cell lines, such as lymphoma (Cl-1), mammary gland (CF33), and connective tissue (CF21).Hypothesis: Maitake PETfraction is effective as a single agent in dogs with lymphoma. Animals: Fifteen dogs with confirmed intermediate or high-grade lymphoma were enrolled into this prospective, noncontrolled, clinical trial. Inclusion criteria were an expected survival time of at least 2 weeks and no major organ dysfunction.Methods: Maitake PETfraction was administered at a dose of 3 drops/kg/day divided into 2 doses given 1 hour before feeding. Dogs were evaluated by physical examination with tumor measurement, body weight, CBC, and chemistry profile before treatment and after 2, 4, 8, and 12 weeks. At each visit, owners completed a questionnaire addressing overall quality of life, appetite, and any adverse effects noted.Results: A decrease in lymph node size of greater than 50% (objective response) was not seen in any of the dogs. Thirteen dogs developed progressive disease before the 4th week. The median treatment duration was 27 days (range, 9-228). PETfraction was well accepted, and minimal adverse effects were observed. Two dogs developed hyphema. It was not known if this was related to progressive lymphoma or was an adverse effect of treatment.Conclusions: No objective responses were observed to administration of Maitake PETfraction, and the drug was well tolerated in these dogs.