Monday, June 9, 2008

An Itchy Situation

The Flea Season is upon us (probably more in other parts of the world - Seattle is still chilly and rainy). I've spent some time over the last couple days catching up on the BEWILDERING array of products available to control these pesky pests.

Fortunately there is a fantastic summary of the products at Veterinary The author has only reviewed the products that are available over the counter or by prescription from vets. She hasn't gone into the pet shop or feed store products.

Most vets have to choose a few select brands/products to carry because there are so many and they all come in various sizes for various sized pets! For example, my current employer offers Frontline, Revolution, Capstar and Sentinel. My last employer only carried Advocate (aka Advantage Multi), Stronghold (aka Revolution) and Program.

The goal of flea control is four-fold: Kill any existing adult fleas, prevent transmission of other parasites (i.e. tapeworms), prevent the hypersensitivity reaction associated with a flea-saliva allergy and prevent development of eggs, larvae and pupae in the environment (i.e. your rugs and bedding!). For this reason, I always recommend products that kill fleas before they have a chance to bite - this takes care of the first, second and third problems on that list. Products that act as insect growth regulators, contraceptions or that have residual activity in hair/skin that the larvae feed on then takes care of the last.

Many products today also provide some degree of protection against other parasites - ticks, lice, roundworms, heartworms and mosquitoes. Your vet can help you decide which parasites your pet is most likely to be exposed to and therefore which product, or combination of products will be most effective. For example: We do not have heartworm in our area, but many of our clients travel with their dogs to heartworm endemic areas, so for these pets we recommend Sentinel which has an insect growth regulator, an internal wormer and a very good heartworm preventative. The trouble is that it does not kill adult fleas AND the fleas actually have to bite the animal to get the medication. If I have a patient who is also allergic to flea saliva, I also recommend a product like Frontline that rapidly kills fleas and keeps them from even biting.

I have always been disappointed with products from the pet shops. Reading their literature, they claim to be as good as the prescription products, but in reality I have rarely found this to be the case. Collars, for example, provide a heavy dose of insecticide in the front half of the animal, but the concentration "tails off" toward the back half and often this is where I find fleas in animals wearing flea collars. The pet shop spot-on products have older and less safe ingredients and I'm not convinced that the "carrier" -- or the solution the active ingredient is mixed with -- is as effective as the veterinary products. They are probably adequate for the non-allergic dog with low exposure to fleas from outside sources. Unfortunately I have seen many disappointed owners unable to understand why their dog is scratching even though it was treated with a pet shop product for fleas just the week before.

Flea treatment is important for your dogs and cats - please use a monthly treatment or at least comb through your animals' coats weekly to check for fleas or "dirts" (the black crumbly droppings from the fleas that dissolve red when wet). Other animals can also get fleas - I have seen rabbits and ferrets with fleas. Rabbits can have Advantage - it is licensed for use in rabbits in the UK and has been used successfully for years. (Frontline is not safe - please do not use it on rabbits). Revolution/Stronghold is safe for ferrets.

If you know that your dog or cat has allergies, even if they are not specifically allergic to flea saliva, it is important to keep them on good flea control. A single bite from a single flea and often push an allergic pet over the edge into uncontrollable scratching leading to skin damage, secondary infections and the potential for a hefty vet bill - certainly more than the flea control would have cost!