Evaluation of an enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of sarcoptic mange in dogs.

Canine scabies is a challenging disease to diagnose because sarcoptic mites are hard to find on skin scrapings. The purpose of this study was to evaluate a serologic enzyme-linked immunosorbent assay (ELISA) as an aid in the diagnosis of canine scabies. In addition, serum samples were obtained post treatment to determine the duration and persistence of circulating scabies antibodies after resolution of natural infection. Nineteen dogs diagnosed with sarcoptic mange and 38 control dogs were tested. Sixteen scabies-infested dogs showed positive pretreatment ELISA results (84.2% sensitivity). Thirty-four control dogs showed negative ELISA results (89.5% specificity). In the 11 scabies dogs from which multiple post treatment serum samples were obtained, detectable antibodies were not present 1 month after treatment in four cases, but were present for 1-4.5 months post treatment in seven dogs. Our results suggest that this scabies ELISA test is useful in the diagnosis of canine scabies.

Cancer of the nasal cavity and paranasal sinuses and exposure to environmental tobacco smoke in pet dogs.

A case-control study of nasal cancer in pet dogs was conducted to test the hypothesis that exposure to environmental tobacco smoke increases risk. Cases (n = 103) were selected from a teaching hospital during 1986-1990. Controls (n = 378) with other forms of cancer were selected from the same study base. Exposure to environmental tobacco smoke was evaluated by determining the number of smokers in the household, the packs of cigarettes smoked per day at home by each smoker, the number of years that each person smoked during the dog's lifetime, and the proportion of time spent indoors by the dog. The crude odds ratio for exposure to environmental tobacco smoke was 1.1 (95% confidence interval (CI) 0.7-1.8) and was unchanged after adjustment for confounders. Skull shape was found to exert a pronounced modifying effect; among dolichocephalic (long-nosed) dogs, the odds ratio for a smoker in the house was 2.0 (95% CI 1.0-4.1). A monotonic increase in the odds ratios across strata of total packs smoked and total indoor exposure to environmental tobacco smoke was found in this group of dogs, with risks of approximately 2.5 for the highest stratum. Conversely, all odds ratios for exposure to environmental tobacco smoke among short- and medium-length-nosed dogs were approximately 0.5. The data support an association between environmental tobacco smoke and canine nasal cancer.

Residential exposure to magnetic fields and risk of canine lymphoma.

A hospital-based case-control study was conducted to determine whether residential exposure to magnetic fields increased risk for canine lymphoma in pet dogs. Cases were patients at a veterinary teaching hospital with histologically confirmed lymphoma diagnosed between 1987 and 1990. Hospital controls with other forms of cancer were obtained by frequency matching on zip code and year of diagnosis. Information regarding the dog's activity patterns, residence history, and exposure to potential confounders was obtained by telephone interview. Wire codes and magnetic fields were measured at the homes at diagnosis of 93 cases and 137 controls. When exposure was categorized into two levels (high or very high wire codes compared with low, very low, or buried lines), the risk was elevated (odds ratio (OR) = 1.6, 95% confidence interval (CI) 0.9-2.9) and increased (OR = 1.8, 95% CI 0.9-3.4) after adjustment for potential confounders. Dogs that lived in homes with very high current codes had the highest risk (OR = 6.8, 95% CI 1.6-28.5). Moderate, imprecise increases in risk (odds ratios of 1.5-1.9) were found for residence in a home with a sidewalk (plumbing), backyard, or front yard magnetic field of 2.0 mG or greater, but not for indoor measurements at this level. Risk increased among dogs that spent more than 25% of the day outdoors. Laboratory and observational studies of dogs as an animal model for the effects of magnetic fields are recommended.