The Ins and Outs of Flea and Tick Control on Cats and Dogs

Jul 30, 2001

The Bottom Line Carefully reading the directions and warnings on products can mean the difference between life and death -- for your pet! In the longrun, you get what you pay for....

There are so many products on the market for flea and tick control, it's tough deciding which ones to try. Combine that with the concern for the environment and other family members (like children), and you're left pulling your hair out!

First, let's go over the basics of the flea life cycle. All those fleas you see on Fido or Felix represent only 5% of the problem. The majority of the fleas are in the egg or larval stages, making it difficult to truly get rid of the flea problem. Once the egg is laid, it soon hatches into a larva, which lives in the carpet/grass eating skin cells, blood from fleas' feces, and anything else it comes across. Once the larva has eaten enough for hibernation, it forms a cocoon. Once in the cocoon, the young flea can survive for years until the conditions are right -- temperature, humidity, nearby FOOD (aka - pets or people). It then emerges, transformed into a young flea, much as a caterpillar transforms into a butterfly. This nymph (young flea) quickly finds a host to feast off of, and then matures into an adult flea. As an adult, fleas typically lay 200+ eggs in the few weeks they are alive.

As you know, there are several options available in the quest to eradicate these tiny insects. Let's start with the natural methods. One option, which may be the only option in very young kittens and puppies, is a flea comb. Used daily, this can remove all of the adult fleas on your pet. Supplements are often tried, such as garlic and citrus juice; these are repellants, and are not very effective for most pets. With both the comb and the supplements, the fleas may not stay on the pet for long, but they generally have time for a meal, which means they have what they need to reproduce.

Next, there are numerous over-the-counter products available. Collars and powders are currently available with one or more of the following ingredients: permethrin, propoxur, carbaryl, dursban, and precor. Dursban is no longer being produced due to toxicity, but there are still products left on shelves with this ingredient (the FDA allowed companies to sell the remainder of what they had produced); it is very effective in killing fleas, but can have serious side effects, especially in cats. Precor is an insect growth regulator (IGR) and is very safe, but it has no effect on adult fleas. IGRs are basically birth control pills for fleas. Propoxur and carbaryl are not particularly effective, but are safe, even as young as 4 weeks old (puppies and kittens). Permethrin can be pretty effective, depending on the concentration; however, cats are highly sensitive, and some dogs have extreme sensitivities to it as well. Permethrin should not be used in puppies younger than 12 weeks old. Regardless of the actual ingredients in the collar or powder, neither is very effective in killing fleas. The powders don't stay on the pet long enough (and are very messy to apply), and the collars are limited to the neck area -- fleas usually prefer the rump or belly. However, flea collars are excellent to use in the vacuum cleaner bag to kill fleas that hatch after vacuumed.

As far as sprays, shampoos, and dips, I have found Adams to be the best. The ingredients again vary, and some products contain more than one ingredient. The least effective I have seen has to be one containing d-Limonene, which is found in orange peels. More effective ones contain pyrethrin or permethrin, and those combined with precor (the IGR) are preferred. Please take note: PERMETHRINS SHOULD NEVER BE USED ON OR AROUND CATS! Overall, sprays and shampoos do well for killing the fleas and ticks on your pet when treated, but once dry, they have no lasting effect. Dips tend to last a little longer, but also tend to carry more risk to your pet.

Oral medications include Program, which must be obtained from a veterinarian, and Hartz Flea Control Capsules (Program is also in Sentinel, a heartworm preventative). Both of these contain IGRs, and have no effect on adult fleas. Again, these are birth-control pills for fleas. Program is available for both dogs and cats, and should be given with food once monthly. The Hartz version is for dogs only, and must be given weekly. Though these are helpful to break the flea cycle, if you have a flea infestation it can take several months for them to make a dent by themselves. It is best to use an adulticide as well to give you and your pet faster relief.

Finally, we are to the spot-on applications. There are two types here: those that are absorbed into the bloodstream, and those that remain topical. All of the over-the-counter products are absorbed, which means the flea must bite your pet to be killed. If the pet suffers from flea allergies, that single bite can cause agony for weeks. In addition, absorbed insecticides/pesticides are more likely to harm the dog or cat they are intended to protect! The absorbables generally contain permethrin or phenothrin plus or minus either precor or (s)methoprene (another IGR). Phenothrin is fairly new, and is a cousin to both permethrin and pyrethrin; it was produced as a replacement for pyrethrin, which is supposed to be pulled from the market. There are also two absorbable spot-ons that are available only through a veterinarian: Kiltix (permethrin, labeled for ticks -- dogs only) and Revolution (selamectrin). Revolution does a good job against fleas and mites, and pretty good against ticks. However, it can be deadly if your dog has heartworms, and therefore does require a negative heartworm test (cats with heartworms rarely have the same complications).

And, I saved the best two for last! Advantage and Frontline Topspot are available only from a veterinarian, and are quite a bit more expensive than products available in the grocery store. However, they are much more effective and unbelievably safer! The main difference is the fact that the flea-killing ingredient is not absorbed, but remains on the surface (in hair follicles and sweat glands). Not only is this safer for the pet's system (it doesn't have to metabolize the product to get rid of it), it means the flea does not have to bite in order to die. Both products work fast enough that fleas rarely have time to lay eggs, and new fleas don't get a chance to bite. Personally, I prefer Advantage for cats and most dogs. Not all pets are the same, though, and if Advantage does not work well for a given pet, Topspot usually does. And, of course, Topspot is for fleas and ticks, whereas Advantage is just for fleas (though some clients have found it to be effective against ticks, it is not labeled as such). Both products help break the cycle by killing the fleas quickly, and by preventing development of larvae feeding on shed skin cells after treatment. [For more information about Advantage, see my article under "Bayer Advantage".]

In summary, Advantage and Frontline Topspot are the best options for flea control (Topspot the best for tick control), and are well worth the extra cost. If you insist on trying the other products, make sure you vacuum daily and throw away the vacuum bag so newly-hatched fleas can't crawl out. Pay particular attention to the ingredients and the directions before you use a product. Try to combine an adulticide with an IGR (birth control). Treat the yard/house at the same time. And, most importantly, if you have a cat in the household, STAY AWAY FROM PERMETHRINS!

Read all comments (1)

About the Author ID:
Location: Atlanta, GA, USA
Reviews written: 4
Trusted by: 1 member
About Me: I am a veterinarian who breeds Persian-Himalayans and Arabian horses.