Reptile & Amphibian Forums

I read with some concern the posts below about the safety of permethrin. Permethrin is in fact quite toxic to reptiles. However, it needs a "route of entry". If you carefully follow the proventamite instructions, you should have no problem. Though permethrin is not easily absorbed through the skin, there are other possible routes of entry. Proventamite instructions clearly state that all vapors should be gone before placing the animal in the cage. Not only is inhalation a route of entry, but permethrin can cause lung damage including cancer. Ingestion is another possible route of entry. If you think that permethrin is harmless to your snake, try putting just a little bit in its water bowl (or allow a permethrin sprayed newspaper or other substrate into the bowl). You will observe firsthand the neurotoxic effects of permethrin. One of my biggest concerns with permethrin is that because animals don't drop over dead folks assume that it is "safe". The truth is that we don't know all of the toxic effects of permethrin on reptiles. We do know of these effects in mammals, and they include: mutagenicity, carcenogenicity, liver disease, immune system suppression, and skin disorders. Oh yea, and reproductive effects, particularly in males (slugs anyone?). If you do have a mite slip through the proper use of permethrin is probably the lesser of two evils, but the key word is "proper". Avoid vapors, keep it out of the water bowl, keep the cage dry, and please don't throw a wet rat on newspaper sprayed with permethrin. In fact, surely the animal can avoid eating for the treatment period.
Permethrin facts.

Thanks for the info. regarding Permethrin. I've known of it's toxicity for years through the horticulture trade. Also am aware that it is the active ingredient in Provent-o-mite, which I've successfully used for years also. I've found Provent-o-mite a great product, but as with any 'pesticide' it needs to be used with care and respect. Reading other threads where people have sprayed it directly on their animals (or their own skin) makes me wince. Maybe it doesn't show any external effect, but skin can absurb all kinds of stuff. I just want to reiterate to others that the directions on a label are there for a reason...to protect you and everyone around you! That label is also a legal document. So if you try to take legal action against the manufacturer of a product that states on the label not to spray directly on the animal (let alone yourself), you're facing an uphill battle. What good is a big $$$ settlement if you've got neurologic damage anyway?!

Steve
-----
"It's not that we don't know...it's just that we don't want to care..." -Wind on the Water, Crosby & Nash

I was the one who posted the picture of the provent-a-mite burn. I have talked with the previous owner and he swears it was caused from the provent-a-mite and as soon he sprayed it into the cage it started rolling around like it was in pain trying to get what was on him off. the snake could have had an open wound from a rat bite or from another cage mate causing the provent-a-mite to cause the damage that it did. Thanks for your post

-Dylan
Pacific Constrictors

Pacific- constrictors.com

I was reading the link you post and it was saying that it can increase aggression behavior. This male that was burned is by far the most aggressive boa I own and have ever seen. When I take him out of the cage he flips out and take off striking at anything in his way, one day I took him out to clean his cage and it took me 15 min. to get in a position to grab his head so I could pick him up to put him back in his cage. This is the only snake I own that scares me.

Barry,
. I followed your link to "facts about permethrin". What I found was that your source of facts is the Journal of Alternative Pesticides. I would not expect them to have anything good to say about any insecticide. The facts are that Permethrin is the active ingredient in NIX which has been used as an antilice shampoo for children for a long time. I believe in following the label directions when working with chemicals but Permethrin did not cause the injury to that Boa and I am not worried about the fact that I have gotten a little overspray from Provent-a-mite on my hands.
Jeff

>>I read with some concern the posts below about the safety of permethrin. Permethrin is in fact quite toxic to reptiles. However, it needs a "route of entry". If you carefully follow the proventamite instructions, you should have no problem. Though permethrin is not easily absorbed through the skin, there are other possible routes of entry. Proventamite instructions clearly state that all vapors should be gone before placing the animal in the cage. Not only is inhalation a route of entry, but permethrin can cause lung damage including cancer. Ingestion is another possible route of entry. If you think that permethrin is harmless to your snake, try putting just a little bit in its water bowl (or allow a permethrin sprayed newspaper or other substrate into the bowl). You will observe firsthand the neurotoxic effects of permethrin. One of my biggest concerns with permethrin is that because animals don't drop over dead folks assume that it is "safe". The truth is that we don't know all of the toxic effects of permethrin on reptiles. We do know of these effects in mammals, and they include: mutagenicity, carcenogenicity, liver disease, immune system suppression, and skin disorders. Oh yea, and reproductive effects, particularly in males (slugs anyone?). If you do have a mite slip through the proper use of permethrin is probably the lesser of two evils, but the key word is "proper". Avoid vapors, keep it out of the water bowl, keep the cage dry, and please don't throw a wet rat on newspaper sprayed with permethrin. In fact, surely the animal can avoid eating for the treatment period.
>>Permethrin facts.

The point which I intended to make was: The fact that permethrin is not readily absorbed through the skin (of humans or reptiles) does not mean that it has no toxicity to reptiles, and therefor we should carefully guard against other routes of entry, such as inhalation or ingestion. I don't see how anyone could have a problem with this. I am making no comment regarding the cause of the wound on the snake to which you and others are referring. I don't denounce the use of permethrin to eradicate mites in reptile collections, in fact I feel that it is the best treatment available, if carefully used. (Prevention through quarantine procedures, is of course the best course of action.) I also don't think that a little over-spray on your hands will hurt you (though I would suggest caution, particularly with a fogger like Black Knight, that one doesn't inhale the stuff).
Permethrin is a synthetic pyrethroid, and is considered safer than many pesticides, primarily organophosphorous and organochlorine. This is partly because it degrades relatively quickly in the environment, particularly in sunlight (Durban's persistence in the environment led to its demise, interestingly its longevity was always considered its greatest attribute). Permethrin does, however, have toxic effects which are well documented, even by the companies that produce the substance. The fact is that it is a pesticide, it's purpose is to kill.
When talking about toxicity the "route of entry" is critical. If a chemical can't touch you it can't hurt you. If it can't get into your system it can't cause systemic effects. Nix may contain permethrin (I'll take your word for it, but there are many natural and synthetic pyrethroids), and it may be safe to use on people as a shampoo. But I would not recommend pouring it on your Cheerios. (Most of the toxic effects documented in the published references on the site I linked to were the result of feeding the pesticide to lab rats and other animals.) Permethrin is not easily absorbed through the skin, but OSHA and the EPA have set limits on allowable levels of permethrin in the air and as residue on food. Proper studies have not been done, but permethrin may be safe to apply to the skin of reptiles. In "Reptile Medicine and Surgery" Mader describes applying synthetic pyrethroids to a snake for mite eradication. However, he says that it should be washed off immediately, and that great care should be taken to keep it away from the nose and mouth of the animal. The point of my post was that the responsible use of permethrin should include great care to insure that it stays out of the water bowl and off of food items.
As to comparing the toxicity of permethrin in humans and reptiles, there are great differences which should be taken into account. (A "scientist" in the sixties and seventies took a tablespoon of DDT every day to prove that it was "safe". The fact that this did not cause acute toxic reactions in him did little for the bird populations that were devasted, to the point of near extinction in one species, due to poor egg calcification.) Though Nix is safe on human heads, we obviously wouldn't want to apply it around Tarantulas or hissing cockroaches. I wouldn't recommend pouring it into an aquarium, either. Not many studies have been done on its effect on reptiles, but its effects on fish are well documented. Read the label of any product in your hardware store which contains permethrin, and you will see severe warnings about applying around water. These companies have a vested interest in downplaying toxic effects, but federal law prohibits applying permethrin within 100 feet of water. The problem is that, unlike humans, fish lack the enzyme to break down permethrin, so it accumulates in the system until it reaches toxic levels. Do reptiles possess this enzyme? I don't know. However, I was listening to a talk given by an entomologist about West Nile virus and Lyme disease. He stated that one of the products (containing permethrin) for use on human clothing comes with a warning that it is extremely toxic to reptiles. (He found this odd, wondering if people would use it to ward off rattlesnakes.) He has since been shipped off to Iraq, but when he gets back I will get more information from him.
Sorry for the long post, but I have recently talked to a couple of people whose snakes showed neurological problems after the improper use of permethrin. There were also several cases this year of people losing valuable animals after feeding them f/t rats purchased mail order. Since most parasites are killed in the freezing process, we have to be open to the possibility that these animals suffered pesticide poisoning. Pesticides, notably permethrin, are often used to control mites and other insects in rat populations. I feel that this is a subject which should be discussed on this forum, and I hope that it doesn't get deleted, but I fear it may. Once again, permethrin properly used probably poses no threat. Improperly used, it does have toxicity, and I feel that we should guard against poisoning our animals through inhalation or ingestion of the pesticide. By the way, most of the recommended uses for Black Knight on reptiles that I hear of would involve a lot of inhalation of the pyrethroid.

Barry,
. The source of "facts" you linked to is heavily biased against all insecticides. In my post I stated that I favor following label directions.
Short and simple.
Jeff

>>The point which I intended to make was: The fact that permethrin is not readily absorbed through the skin (of humans or reptiles) does not mean that it has no toxicity to reptiles, and therefor we should carefully guard against other routes of entry, such as inhalation or ingestion. I don't see how anyone could have a problem with this. I am making no comment regarding the cause of the wound on the snake to which you and others are referring. I don't denounce the use of permethrin to eradicate mites in reptile collections, in fact I feel that it is the best treatment available, if carefully used. (Prevention through quarantine procedures, is of course the best course of action.) I also don't think that a little