Monday, February 7, 2011

Cyphenothrin use on dogs, EPA wusses out

So the US EPA not to long ago put out this press release about spot-on flea products for pets. The current webpage is located here: http://www.epa.gov/pesticides/health/flea-tick-control.html

The original webpage at the above address (which I'm unable to find on archive sites, I wish someone had a copy) actually had a very short list of products under investigation because, and I'm paraphrasing here, of the high incidence of reported adverse effects associated with them.

My personal guess is that the handful of companies whose products were on that list had a hissy fit. So the EPA replaced it with a long list of every possible flea product, saying:

"Since the chart previously located on this page reflected only a portion of the numerous pet spot-on products available, EPA felt that pet owners and consumers might be led to believe that only those products listed were the focus of concern. In fact, EPA is intensifying its evaluation of all spot-on products and is providing a more comprehensive list of these products."

I remember very clearly the name of one of the products that was on the original short list. Sergeant's Cyphenothrin + IGR Squeeze on for Dogs (AKA Sergeant's Gold) I even remember the EPA registration number (2517-80). It's an over-the-counter spot-on that contains a ridiculously high amount (40%) of the pyrethroid cyphenothrin (known effects of over-exposure in mammals: skin irritation, muscle twitching, and in extreme cases, seizures).

It's a relatively new product. It's first approval date was late 2006 (according to PPLS http://oaspub.epa.gov/pestlabl/ppls.home ).

Take a look at this internal EPA memorandum that was recently released under FOIA:

http://www.epa.gov/opp00001/foia/reviews/129013/129013-2005-06-27a.pdf

The memo talks about two studies. The first one was to look for possible adverse effects. The results were what you get effects like what you'd expect from a flea product of normal risk: groups of dogs given the normal dose didn't have adverse effects, but over dosing did cause problems.

The second study (which was looking at efficacy of product to kill fleas like the label claims and only observed health effects as a side note), all dogs given a normal dose had very bad (and consistent) adverse reactions. This is bad. This is a HUGE inconsistency and should have stopped the approval of this product cold until it could be resolved. It's so fishy I can smell it.

"There are obviously then some significant inconsistencies between the findings in the companion animal safety study in MRID 46166108 and the efficacy study in MRID 46166109. The occurrence of neurological signs of toxicity in all 6 dogs in the efficacy study suggests that there is not even a 2x margin of safety associated with the proposed application rate of 1.17 mL"


Note the studies mentioned in the memo have numbers instead of titles. This usually means that they are unpublished and not available to the public. This is not out of the ordinary, EPA requires pesticide companies to submit studies like this all the time. The strict laboratory standards (GLP) are supposed to stop any falsifying of data.

Why did they ignore this inconsistency? Why did the product go on the market without change to the formula? The only thing that may be different is the size of the application.

The actual approved product labels on PPLS list application tube sizes as 1.5mL (making it the 1.17mL dose) (9-20 lbs dogs) 3.0mL (expected dose: 2.34mL)(21-39 lbs) 4.5mL (expected dose 3.51mL)(40-60lb) and 6.0 mL (60+ lb).

These sizes seem to be at or larger than the doses in the study that caused 100% of dogs to have serious reactions. In fact, the memo says that the proposed label dose should be 1.17 mL of a 40% concentration. I'm confused by this, and I'm wondering if I'm missing something. It looks like they INCREASED the dose for the actual product. To meet efficacy requirements? If so, that's nuts.

The efficacy study gave higher doses than the safety study, also. so that makes more sense.

I wonder, of course, if there was an error with the study. The actual concentration used was higher than reported. Still. This known inconsistency, combined with the fact that the product contains a very high concentration of cyphenothrin AND that the product appears to get more than it's fair share of adverse effects reports should be a big ol' red flag.

Why is EPA being all wishy washy and not singling this product out in public? They haven't had a problem with that in the past. A stop sale should have happened months ago, in my humble opinion. Get it sorted, if it turns out the adverse effects reports are within normal risk range, then let the company continue to sell. If not, do what FIFRA says is supposed to happen, and make them re-evaluate their dosing and concentrations.


No comments:

Post a Comment