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  Discussion on Malathion/Fyfanon Product used to fog for mosquitos
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New Member:
cindy333

Posted on Thursday, May 1, 2008 - 9:18 am:

Our county fogs for mosquitos starting in May, Per our request they come in on our farm and fog
very well on three sides of our main pasture.
In 2007 we had mares who had been ultrasounded in
foal 20-35 plus days and put out to pasture.
These mares had embronic heart measures when put out. We had 12 mares go empty on us that had been in that pasture during the May / June / July/August fogging season. I have been searching for answers, I have the MSDS sheets for the Fyfanon ULV product, not being technical, it sounds scary to me. We have been a breeding farm for 15+ years, and we always expect a couple of mares to go empty for what ever reason, but not a whole pasture of them. We are NOT seeking recourse for this from the county, they fogged per our request and did a very good job, we only need to know if this could cause the mares to go empty, if fogging was at a critical time in embronic development and attachment. We just got our notice card asking if we wanted the farm to be fogged again this year, I need to respond by May 9. I would also like to know if there is any significant data anywhere that would support this event. If so, I think there is a human concern that is greater. I appreciate your input DrO.
Member:
ekaufman

Posted on Thursday, May 1, 2008 - 2:28 pm:

Hi Cindy,

I assume you've double-checked that this is the compound in use? My county sprays for mosquitoes (we are frequently tops in the country for WNV, including 2 horse cases at my barn last year). Here they use a pyrethrin in a citrus oil base. We're a big ag. area, so perhaps they are unusually safety conscious.

An additional stupid question-- are you pasture breeding? If so, did the stallion used on those mares successfully settle other mares last year?

I realize you've probably already answered these questions long ago. I hope you figure out what's up for next year's foal crop.
Member:
ttownzen

Posted on Thursday, May 1, 2008 - 2:56 pm:

I don't know if this is of any use, but we were using an "all natural" wipe on our horses one year that included a pennyroyal extract. I was told that it had been linked to spontaneous abortion.
Member:
cindy333

Posted on Thursday, May 1, 2008 - 5:37 pm:

Elizabeth, I have checked, I went to our department of mosquito control and they gave me the MSDS sheet. I didn't question them about my concern as I wanted good answers. They said they are using another product this year, KONTROL4-4. with active ingredients: Permethrin, Piperonyl Butoxide Technical and Intert ingredients, which list a pertroleum distillate solvent, but that doesn't change much. Malathion/Fyfanon ULV is not a product that they spray with as I think they spry ditches, ponds, etc with a Bt, (Bacillus thuringiensis) The malathion/fyfanon ULV is a fogged product, I think they use petroleum /oil to make the fog, It is a very heavy fog that lays in heavy over everything, they do say, do not breath this for humans. (what about animals?) From the MSDS sheet, it says it is a cholinesterase inhibitor of low mammalian toxicity, however it says that storage at too high of temperatures may induce formation of a much more toxic and synergistic contaminant isomalathion. It also says the Malathion and isomalathion are poisons through ingestion, with symptoms similar to those listed for inhalation.
The MSDS sheet under regulatory information states: United States: California Proposition 65 information: This product does not contain any chemicals known to the state of California to cause cancer or reproductive harm. I wonder how it is that California can make claim for the whole U.S. Thanks for anything you can dig up on it or anyone one else who has had issues with pesticides and abortions, I am hoping someone has had some experience with it and can fill in more blanks to the possibility of equine abortion. I went back to check records, we actually had 14 mares go empty this spring. Pretty hard lump to swallow. Thanks for your note. Terri I have not heard of pennyroyal extract but any concern is a big concern for a breeding farm, let alone human health complications that may arise. I do appreciate your notes.
Cindy
Member:
cindy333

Posted on Thursday, May 1, 2008 - 5:47 pm:

We don't pasture breed. Mares are washed and wrapped, and the stallion is washed after each breeding. The mares that were in another pasture, that did not get the direct fogging each time, had foals. All the mares that we bred and that left to go back to the client farms foaled this year. Boy, I'm just trying to figure this one out.
Member:
ekaufman

Posted on Friday, May 2, 2008 - 1:15 am:

Hi Cindy,

Well, I'd be right there in the pasture with you looking for possible causes. I suppose other possibilities might be a patch of toxic weeds, or potentially if one of the mares infected every single other one with something (a nasty flu? something else?) that caused early abortion.

Let us know what you find out. 14 open is pretty gruesome. Did you culture any of them to see if there was any sign of infection?
Moderator:
DrO

Posted on Friday, May 2, 2008 - 7:17 am:

Fyfanon ULV is a brand name for the very commonly found and long time used insecticide malathion, a cholinesterase inhibitor. There is a good study in humans with exposure to aerial spraying. It suggests the practice did not effect pregnancy. In studies with rats those fed large doses for several years did not have problems. When fed truly huge doses of 240 mg/kg daily there was an increase in newborn mortality. This would be equivalent to a horse ingesting 108 grams (1/4 lb) daily. Last year it would be interesting to see what the blood cholinesterase levels were of the empty mares. In summary it seems unlikely that properly handled and applied malathion spray would cause early abortion in mares but this has not been tested on horses.

All that said, I would not lightly choose to lay down large amounts of insecticide on pastures that the horses graze. I suspect this results in higher levels of exposure than aerial spraying of people. But this will have to be balanced against mosquito control and the prevention of disease transmission.
DrO

Here is the study in humans with aerial exposure:

Epidemiology. 1992 Jan;3(1):32-9.
Reproductive outcomes in relation to malathion spraying in the San Francisco Bay Area, 1981-1982.
Thomas DC, Petitti DB, Goldhaber M, Swan SH, Rappaport EB, Hertz-Picciotto I.
Department of Preventive Medicine, University of Southern California, Los Angeles 90033-9987.

We studied reproductive outcomes in a cohort of 7,450 pregnancies identified through three Kaiser-Permanente facilities in the San Francisco Bay Area, in relation to exposure to the pesticide malathion, applied aerially to control an infestation by the Mediterranean fruit fly. We included in the cohort all women over age 17 who were registered at these facilities and who were confirmed as pregnant during the spraying period. Residence histories throughout the pregnancy were obtained by mailed questionnaire or telephone interview from 933 women with adverse outcomes and a sample of 1,000 women with normal outcomes, and were converted to geographical coordinates. We linked the coordinates for malathion spraying corridors with the residence coordinates to create individual exposure indices for each week of pregnancy. The statistical analysis compared each of the adverse pregnancy outcome groups against an appropriate control group using logistic regression or survival time regression approaches. After adjustment for various confounders, no important association was found between malathion exposure and spontaneous abortion, intrauterine growth retardation, stillbirth, or most categories of congenital anomalies. Gastrointestinal anomalies were related to second trimester exposure (odds ratio = 2.6), based on 13 cases and not specific to any particular International Classification of Diseases code.
Moderator:
DrO

Posted on Friday, May 2, 2008 - 7:49 am:

Cindy, I was remiss in not referring you to our section that contains general and specific articles on causes of abortion. Melissa is right, if we assume the pregnancy diagnosis is correct, you should be looking for other toxic and infectious causes of abortion.
DrO
Member:
cindy333

Posted on Friday, May 2, 2008 - 8:32 am:

Thanks DrO and Elizabeth, I am so glad to see the info on the testing done in California, It settles me a little. I will do a check of the field, We did nothing different than we have in the past number of years, we vaccinate, we worm on a schedule, check and float teeth twice a year and feed well. Just so strange to have so many go
empty, We have never encountered this before in all the years of breeding. Thanks so much for your replys...I will keep checking on this to see how it goes this year. Your right, had we known they were empty or going empty last year we would have had testing done on them. Each mare is cultured prior to breeding every year, When we started breeding this year all were cultured and we had only two mares come up dirty, They were mares coming off the track, We cultured them last year, settled them and verified that they were in foal with ultrasound and turned them out last year, but didn't hold their pregnancy, Prior to breeding this year they did come up dirty and we treated them. Those kind are not a surprise, and the fact that they didn't culture clean before breeding this year confirms. Well guys, again thanks so much! Cindy
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