There are many flea and tick products- shampoos, sprays, spot-on treatments, and spot-on treatments. There are several factors that should be evaluated when choosing a flea and tick product for your dogs and cats.
Shampoos, sprays and many spot-on treatments to include Frontline are products of the past. Many are safe but ineffective. Fleas and ticks have changed susceptibility to them and they no longer work effectively as they once did. Others work but only for a short time. The one exception is permethrins ( Toxic to cats). This is one of the active ingredients in the popular dog product Advantix. This product, if used correctly, is fairly safe.
There are concerns about Permethrin, the topical insecticide, which is known to not rapidly harm most mammals or birds, with the exception of cats and fish where it is dangerously toxic. What about long term use of Permethrin? Permethrin is a suspected carcinogen, endocrine toxicant, liver toxicant, neurotoxicant, and reproductive toxicant. All of these side effects are significant problems that occur in dogs. Therefore, safer products are preferred for my furry friends.
Isoxazoline recently entered the market. It is extremely effective against both fleas and ticks. The most common side effects noted have been vomiting, diarrhea, and short term lethargy. These side effects are observed in 1 out 10,000 patients with no lasting side effects. The current isoxazolines available are Nexgard ( monthly chewable for dogs), Simparica (monthly chewable for dogs), Bravecto 3 month chewable for dogs or three months topical for cats), and Revolution Plus for cats (contains topical Simparica for cats), and Credelio (oral monthly for cats and dogs).
These products meet all three of our criteria of being extremely effective, safe in nearly 100% of our pets ( no product is 100% safe), and convenient.