Comparison of Oral and Topical Flea & Tick Treatments

Oral and Topical Flea and Tick Medications
S. Mason, DVM

There are a lot of medications on the market for use on dogs and cats for ectoparasites (fleas/ticks/lice) and many of these medications are also available to treat internal (often intestinal) parasites as well. There are some products, available only by veterinary prescription, that combine flea and tick control with the prevention of heartworm disease for both dogs and cats. Unfortunately, the variety and availability of these medications is confusing to pet owners. This is because many topical ectoparasiticides are pesticides licensed with EPA, while many of the veterinary only products are actually licensed with FDA. This difference means that most of the veterinary approved products are not available except by prescription because they are licensed by FDA. In general, many of the veterinary approved products also prevent heartworms. Therefore, to be simplistic, medications that prevent heartworms are not going to be available over the counter (OTC) and must be prescribed by a veterinarian.

The chart below is provided as a quick reference. In the discussion below, the products are divided into canine (dog) and feline(cat) categories, as many product formulations are different between the two species or are only available for dogs. The chart also only includes veterinary approved products and not the general OTC products (most of which are licensed by EPA). Therefore, not all available flea and tick products are included in this survey. The main reason for many OTC products from chain store products being excluded is that they are often organophosphate based; and therefore, I would NOT recommend their use on ANY CATS, or young or elderly dogs. I am not advocating their use at all, but the risk of a reaction to these products is much greater in the above listed groups. Secondly, if reactions do occur, they are typically more severe than with the safer veterinary only products.