Tuesday, August 28, 2007

Toxicology Tuesday, August 28

How do you answer this week's Toxicology quiz?

Toxic or Not?

What do all these products have in common? Each of the above items (except the Hartz product) contains 45-65% permethrin, a synthetic insecticide. (The last item contains phenothrin, a similar agent.) Permethrins have a good margin of safety in dogs, but even a small amount of any of these products are TOXIC to cats.

Pyrethrins are the natural pesticides derived from chrysanthemum flowers, which are very safe and which break down quickly. They can be used in cats and young animals with little to no risk of injury. (Note: Anything is potentially toxic to an animal with a sensitivity to that agent.) Man-made pyrethoids like permethrin last a lot longer and are safe for dogs. The packages always bear warning labels saying not for use in cats, though some are more obvious than others. There are at least 18 different permethrin products available, and it doesn't matter if you get one from a veterinarian, the Internet, a pet store, or any other source - permethrins extremely toxic for cats.

Permethrin toxicity is one of the most commonly encountered poisonings in cats. While some cases occur accidentally, most are caused by owners who deliberately ignored the package labels, applying it to cats in spite of the cautions. I can’t count the number of permethrin toxicities I have treated over the years, and every case was caused by operator-error. Excuses were usually “I just put on half; I only used a little,” and so forth. NOT FOR USE ON CATS means none, never, ever, not even half the tube, not even a little bit, none whatsoever.

Other cases are the result of accidental application, or rarely by cats coming in close contact (grooming, cuddling) with dogs who have had these products applied. My cats frequently snuggle up with my dogs – I won’t have a permethrin product in my house.

Signs may appear within a few hours but can take up to 72 hours to show up. Muscle tremors are most common, and seizures may occur. With aggressive (and expensive) treatment (decontamination, IV fluids and medications like methocarbamol for tremors and diazepam for seizures) the prognosis is good.

If you accidentally apply a dog product to your cat, bathe it in Dawn dish detergent immediately and contact your vet. If your cat is already symptomatic, skip the bath and go directly to an emergency service for intensive care.


Lynne said...

Since the directions for all of the topical flea and tick killers that I've seen say to apply between the shoulders where pets can't rech to lick, I'll say toxic.

Anonymous said...

When used as directed, probably not toxic. If ingested, probably toxic. I've heard of some dogs being sensitive to these products even when used as directed, so I haven't used any on my dogs for quite awhile. They don't seem to be bothered by fleas in eastern Washington, like they were in western Washington. Kathy

littleorangeguy said...

I always wonder when you post multiple examples... Do all these products have the same active ingredient? Some look like they could be bought at any box store while others have that distinctive Boutique Vet look. Either way, I'm clueless, seeing as how I am ...

Flealess in Toronto

Anonymous said...

All the products have some definite toxicity, although the level may be very low. Most of them have a wide margin of safety, but must be used properly. Very big reason to get them from your veterinarian instead of mail order. Some flea/tick preventatives can be fatal to cats.

KGMom said...

This one looks suspiciously like a trick toxic post. Since the product is designed to be put on animals, one SHOULD assume it is not toxic, at least on the skin.
But, since you asked, is it possibly toxic if ingested?
All I know is my dog HATES the between the shoulders application of this product. She growls at me as if to say--don't do that. So I trick her and take the tube along when we walk, sneaking little dabs on her while she is otherwise occupied.

nina said...

I was going to mention the cat toxicity too--we're warned to keep the treated dog away from areas the cats frequent.

KatDoc said...

Yes, this was sort of a "trick" post. The key here is that all these products are for DOGS, not cats (Nina & Anon #2 picked up on that.) Anon #1 (Kathy) also pointed out that even though these flea and tick products are GENERALLY considered safe for dogs, some may be more sensitive than others to the active agent in any insecticide.

They do all contain the same ingredient, permethrin, which isn't toxic to dogs orally, but if it is licked off it will be less effective, which is why you are advised to put topicals where the dog can't lick. Some animals object to the feel of any topical application, and the rare animal may actually get a red, inflamed spot where it was applied.

As always, your personal veterinarian is the best source of advice for parasite control in your pet. (Unless you are lucky enough to live in Toronto or eastern Washington, where apparently, fleas are forbidden.)

Thanks for playing our game!