Uh Doc, My Dog's Got Critters
OK, so you just found out that Fido is running 30 head of tiny livestock on his "back 40." What the heck are you going to do about it? First of all, don't panic, we have many new weapons in the war on fleas. Let's take a look at the different flea control products available, and how best to utilize them to treat and prevent flea infestations.
Adult fleas represent a small percentage (5%) of any given flea infestation. Egg and larval stages make up the bulk of the population, and pupal stages are troublesome as well. In order to effectively eliminate a flea infestation, the pets and their environment (indoor and outdoor) must be treated for all flea life stages.
In the past, flea treatment relied primarily on adulticides, compounds that kill adult fleas. These compounds, such as pyrethrins, permethrin, and carbaryl, took the form of dips, sprays, shampoos and powders. Since adult fleas are such a small part of the overall problem, reliance strictly on adulticides was rarely totally effective. Flea control took a large step forward with the development of insect growth regulators (IGR's). IGR's are compounds that kill flea eggs and larvae, or prevent them from developing normally. The commonly used IGR's are methoprene, pyriproxifen, and lufenuron. Methoprene and pyriproxifen are available in a number of formulations, including collars, on-animal sprays, and environmental sprays/foggers. They are highly effective at inhibiting the development of flea eggs and larvae, and are very safe for mammals (2-legged as well as 4 legged). Lufenuron (Program) is available as a once-a-month pill for dogs, and a once-every-6 months injectable for cats. When a flea bites a lufenuron treated dog and ingests a blood meal, it also ingests a small amount of lufenuron. This prevents the eggs laid by the flea from hatching. Lufenuron also inhibits the normal development of flea larvae. It is important to note that none of the IGR's kill adult fleas, thus they should be used in conjunction with an adulticide for treating a preexisting flea infestation.
Two new flea adulticides have been introduced in the last few years. They are fipronil (Frontline) and imidacloprid (Advantage). Imidacloprid and fipronil are available as "spot-on" products. "Spot-on" products are applied topically to a small area of skin, and migrate across the animal's body to provide protection. Fipronil is also available in a spray formulation. Both of these products are very effective at treating and controlling flea infestations. In our office the spot-on version of fipronil (Frontline Topspot) is our primary product for on-animal use.
So how do we use all these new products rationally? As always, consult your family veterinarian for his/her specific recommendations. In our practice, we take a proactive stance towards fleas, preferring to prevent them from becoming a problem in the first place. In a flea-free household, I recommend spraying indoors with an IGR (methoprene or pyriproxifen) once every 3-6 months, and using Frontline Topspot on the animal every one to two months. Advantage used monthly is also very effective. Program is effective at preventing the development of a flea infestation, but will not kill adult fleas the animal does pick up.
For preexisting infestations we treat the indoor environment more aggressively. I recommend a thorough vacuuming of the entire area, including upholstery. The vacuum bag should be thrown away. Then, spray or fog the entire area with a product that combines an IGR with an adulticide. In our practice we use Ectokyl IGR Pressurized Spray. Keep in mind that the flea pupae in the environment will remain viable. Therefore, I recommend repeating the vacuuming and area treatment one month later to kill the newly hatched adult fleas. Remember that carpeted areas are the prime areas for flea development. Of course, you should also be treating the dog as described above.
Outside areas are also a concern in flea infestations. Keeping grass cut short and yard debris (leaves, grass clippings, etc.) picked up will help reduce flea reproduction outside. You may also treat the area with any number of broad-spectrum insecticides, paying particular attention to areas the animal frequents, i.e., under decks, porches, and bushes.
Just a few comments now about the products mentioned in this column. Every veterinarian has his/her favorite combination of flea products, and you should follow your veterinarian's recommendations. I prefer Frontline to Advantage and Program, because of its slightly longer duration of activity and its additional protection against tick infestations when used monthly. However, all of these new products represent quantum leaps forward in flea control, and are very effective when used appropriately. (Always follow product label instructions.) The best course of action is to be proactive, and take steps to prevent fleas from becoming a problem for your dog.