are hartz flea and tick collars safe?
Hartz UltraGuard Flea & Tick Collar for Dogs is a fast-acting collar solution that quickly kills fleas and ticks, and lasts for 7 months. This collar has a clean, fresh scent and is water resistant. It fits necks up to 20 inches. ... Safe, easy, and effective treatment for dogs and puppies 6 weeks of age and older.