Evaluation of a carbamate-impregnated flea and tick collar for dogs.

To acquire information regarding the potential hazard of pesticide-impregnated collars to dogs, 13 male Beagles were allotted to 2 groups; 8 of the dogs were fitted wtih propoxur-impregnated tick and flea collars and the other 5 were fitted with placebo collars. All dogs wore their collars for 42 consecutive days. The dogs wearing test collars had significant (P less than 0.01) depression of erythrocyte and plasma cholinesterase activities at day 1 after collar application; however, the enzyme activity values returned to the preexposure range within 3 days. Miosis, with decreased pupillary response, was noticed during the 1st week of exposure. Irritation of the skin of the neck was mild and transient in both the test and control groups from the 2nd week onward.