Permethrin and Cats...

[brdeturk]

So I made a mistake... I treated my chickens with Permethrin powder without realizing how much of a mess it would make. I have three indoor/outdoor cats that love to go and watch the chickens during the day and will inevitably walk through the powder that's sprinkled throughout the grass. In retrospect I would probably have tried to find an alternative method to treat for lice/mites but I can't go back now. What's done is done. How long should I wait before letting the cats out of the house? Would rinsing the grass off with the hose help out the process? I know Permethrin powder is not as dangerous to cats as the liquid form, but can anyone help me out with this?

 

[chickengeorgeto]

Although I use a 10% or a 40% liquid Permethrin concentrate mixed with water to spray my chickens. In over 30 years of owning chickens and cats, side by side I have never seen any negative impact on any of my or on any of my daughters' cats. There are a lot of post on line claiming negative consequences if cats are exposed to Permethrin and Pyrethrin but none of the claims are backed up by scientific research. The best that I can find in the way of scientific research is that Permethrin as well as 100% natural, renewable, certified Organic, and safe for the Earth Pyrethrin is that these two insecticides are safe for use on every warm blooded animal with a back bone. The only difference is that Pyrethrin is much more expensive, much less effective, has an extremely short shelf life, and once deployed only remains effective for less than 24 Hours, especially in the presence of Sun light. In fact there is a save or cream containing 5% Pyrethrin or Permethrin that is sold over the counter for use on human infants who have scabies mites. So the competitors running down Pyrethrin or Permethrin evidently think that cats are more tender than day old human infants.

Now which did you buy, Permethrin or Pyrethrin? I assume that you dusted your chickens out of doors and used Pyrethrin powder because a powder is the normal way that Pyrethrin is sold, in which case both your chicken mites and your cats will be perfectly safe by Sun down tomorrow.

 

[Aerliss]

So the competitors running down Pyrethrin or Permethrin evidently think that cats are more tender than day old human infants.

Different animals have different physiologies and metabolic processes. For example, thalidomide was tested on Guinea pigs and found to be perfectly safe, but use in humans results in physical deformations of babies.

With regards to permethrin;

"While SPs are relatively non-toxic in most mammals, cats are noted for their inability to metabolise and biotransform certain compounds and as a species are very sensitive to adverse reactions to this drug[4]. The specific reason for increased sensitivity of cats to permethrin is probably complex, but thought to be associated with a deficiency in glucuronidase, which is necessary for permethrin metabolism via glucuronidation. Further, the hydrolytic enzymes that degrade pyrethroid esters have a slow rate of hydrolysis in cats, compared with other species, thus increasing their susceptibility[5]."

http://vetbook.org/wiki/cat/index.php?title=Pyrethrin_toxicity

There are hundreds of articles on Google Scholar about veterinary cases of permethrin toxicity in cats. 10% resulted in death, according to the ones I looked at. Mostly they are from cats being treated with dog spot on, but many resulted from accidental exposure.

The important thing is what the concentration was. Over 40%, applied directly, results in severe toxicity, and possible death. A lower concentration, particularly if its accidental, will be less toxic.