Sawyer Permethrin Insect Repellent Treatment for Dogs controls ticks for up to 6 weeks and fleas and lice for 35 days. The odorless treatment can be used to treat dog beds, kennels, seat covers, and more without harm to fabrics or finishes. Sawyer Permethrin Insect Repellent Treatment for Dogs is effective for 6 weeks or 6 washings on fabric. It effectively repels and kills ticks which can carry Lyme disease and Rocky Mountain Spotted Fever. 24-oz. trigger spray. Note: Do not use on cats.