BOT flies - deworm again?


Laura and Ero
 

I dewormed using ECIR protocol this April (ivermectin, double-dose Strongid). Yesterday I found BOT flies on my horse's legs. I removed by hand, but wondering if I should deworm again and if so with what product? 

Vet happens to be out shortly (for another horse), but would it be worthwhile to have a fecal sample done? 

--
Laura and Ero

October 2020 | Erin, WI USA 

Ero Case History

Ero Photo Album


Eleanor Kellon, VMD
 

It's still early in the bot fly season and life cycle. Read about it here https://foundationequine.com/blog//horse-stomach-bots . Warm soapy water will hatch most of the eggs but there are also bot species that lay eggs around the mouth.  The rationale for waiting until the first frost to deworm is that the horse won't get reinfected but in years with heavy infestations I wouldn't wait that long. Ivermectin kills all life stages, including in the mouth. This is what the inside of the horse's stomach can look like in a few months https://cdn.meddletonequine.com/articles/171/bot-fly-larve__medium.jpg .
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Eleanor in PA

www.drkellon.com 
EC Owner 2001


 

Hi, Laura. 
Ivermectin is effective against bots. https://aaep.org/sites/default/files/2021-03/Internal_Parasite_Guidelines.pdf  

Deworming at least quarterly is good practice where your horse is boarded with other equines where he has risks of exposures. With all the mysteries we face treating our horses, I personally believe deworming for parasites using an acknowledged effective dewormer is an easy choice. A fecal sample won't hurt, but to quote the AAEP, 
"It is important to note that a negative fecal examination does not mean the horse is free of internal parasites. Some types of parasites produce eggs only intermittently. Larvae do not produce eggs at all, and may be present in large numbers in a horse with a fecal egg count of zero. And tapeworm eggs may be missed with routine fecal egg count techniques."

There is a ton of information about deworming in the Horsekeeping sub group. Dr Kellon offers a short online course on Deworming that removes most of the mystery on the control of internal parasite. I recommend it. http://drkellon.com/shortcourses.html 
--
Cass, Sonoma Co., CA 2012
ECIR Group Moderator
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Laura and Ero
 

Thank you. For clarity, should I give him a tube of ivermectin again now? 


He had been quarterly dewormed at a large boarding barn. Once he was determined EMS (about 2 years ago) we moved to a twice a year (spring and fall) ivermectin & 2x Strongid 2 weeks apart. 


Should I switch back to Equimax in Fall despite the concerns with some of the ingredients?


--
Laura and Ero

October 2020 | Erin, WI USA 

Ero Case History

Ero Photo Album


Eleanor Kellon, VMD
 

If you are constantly finding large amounts of bot eggs on him, deworm with ivermectin in mid summer in addition to the fall deworming. Double dose strongid is fine for tapes as long as you do it twice, two weeks apart.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001


Eleanor Kellon, VMD
 

BTW, having EMS does not mean you should deworm less often.  The drugs themselves are not going to cause laminitis. It's a systemic reaction to a large worm kill that might cause issues with the feet. To avoid that, you want to deworm regularly. Quarterly is a good place to start.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001


Ditte
 

  I read somewhere that wiping the BOT fly eggs with ethanol will destroy them by drying them out (easier than removing them). Does it kill them or is it a waste of time? And if it works how often would you need to do it? My horses haven't been dewormed for 10 years! You can't get dewormers in Denmark without a fecal egg count. I just had them tested and as usual numbers were low (0 and below 50). 
--
   Ditte
   Denmark
   June 2019


Eleanor Kellon, VMD
 

I don't know about ethanol but hot soapy water will make them hatch. Bots won't show up on a fecal egg count. Fecals are also unreliable for tapeworms.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001