Veterinarian recommended K9 Advantix II kills parasites through contact – no biting required. Did you know that flea bites can cause flea allergy dermatitis (FAD) and skin infections? A single flea can lay up to 50 eggs per day leading to infestations even in your home. In addition to biting and feeding on pets, ticks can transmit diseases like Lyme disease. Bites from infected mosquitoes can spread heartworm disease. DO NOT USE K9 Advantix II ON CATS.