How long are sedatives detectable in a drug test?

[kaileymindle]

This is in reference to USEF drug rules. I play by the rules, trust me, I would never drug a horse for the sake of winning a class or dumbing down a hunter. I’m simply wondering how long after dosing Xylazine or Ace would it no longer be detectable on a drug test. I cant find much online, but when I do it says 72-120 hours. Is it really that quickly out of their system? (By IM if that makes any difference.)

So here’s the situation, I have a horse that’s difficult to clip, like sedative-needing difficult to clip. The issue though is that our show schedule overlaps with Winter, so he will need to be clipped a few times during so. Leaving his coat as-is is not an option, we are constantly traveling from Ohio to Floridia and he would bake in heavy work with all that hair. I bought him in March and he came to me with a trace clip, so he’s been clipped before, but either he’s had poor experiences or was sedated. Maybe a mix of both. I’ve been working with him almost everyday from May to now and seeing some improvement, but he’s still so stressed and it’s simply not fair to ask him to endure it.

Sorry for the long winded explanation, I’m not asking for training advice but I knew I might get some backlash for using “shortcuts” in my training if not. Like everyone else, I’m just trying to be a good horseman and do right by my animals.

[MHM]

Whatever the drug clearance is that you can find listed, double or triple it to be on the safe side.

A friend of mine sedated a horse to clip it some years back, in what seemed like plenty of time in advance, and he got set down for something like two months after the horse was drug tested. It turned out the horse had some sort of underlying health issue that made it slow to metabolize the sedative.

Very unfortunate outcome for my friend, who had been in the horse business for about 40 years with absolutely no problem ever with a drug test result. Until that one horse.

[Ghazzu]

Depends upon multiple factors including dose of drug, route of administration, and individual variations in metabolism/excretion.
There’s a 2017 publication ( Pharmacokinetic and pharmacodynamics of xylazine administered to exercised thoroughbred horses --Heather K. Knych, Scott D. Stanley, Dan S. McKemie, Rick M. Arthur, Ulf Bondesson, Mikael Hedeland, Mario Thevis, Philip H. Kass in
Drug Testing and Analysis, V9:5, 713-720, 2017) which looked at 200 mg xylazine given IV to TBs, and found detectable serum levels at 72 hours, although it was noted that clinical effects were much shorter-lived.

'Additionally, 10 of the 16 horses studied had serum concentrations in excess of the current ARCI recommended regulatory threshold (0.01 ng/mL) at 48 hours suggesting that this drug should be used cautiously in racehorses and an extended withdrawal time may be warranted to avoid an inadvertent positive regulatory finding"

[Newberry]

Involve your veterinarian and get a medication report form. This will keep you in the clear if you follow the rules. It allows USEF to have a record, basically, of how and when this drug was given, and that it wasn’t given inside their requested withdrawal period.

[CBoylen]

You cannot file a med report for clipping.
Rule of thumb is 72 hours but USEF recommends 7 days.

[vxf111]

Surely you’re not showing literally every day all winter long? Lots of people use sedatives to clip or for dentistry or for other non-doping reasons and still show plenty. I always heard Ace was testable for 72 hours after it was given. There must be a three or four day stretch here and there over the winter when you’re not showing. If not, maybe you should give your horse a break and this is the universe telling you to do so. FWIW I think there’s nothing wrong with giving a little sedation to clip. Some horses just need it and have a better experience that way.

[kaileymindle]

Eek!! No, no, don’t worry my horses get break time even when showing!! For every week they show, they get at least a week to relax at home, minimum. The Monday and Tuesday following are always a complete off days. They do two weeks in Florida consecutively, but again, have a nice fat break upon coming home. I was just worried because of my one on, one off, type of schedule. I wasn’t sure if a week would be long enough for the sedative to get out of their system or not!

[LCDR]

What drug are you planning to use?

[kaileymindle]

Ace is my first pick but I would be fine using Xylazine as well.

[vxf111]

If you clip at the beginning of the “off” week you should be fine.

[Gardenhorse]

The USEF medication rules say how long many drugs are detectable. https://www.usef.org/forms-pubs/2Zp2C_YKs4s/2022-equine-drugs-medications

Also, they are very helpful if you email them with a question.

[Bonnie2]

Ideally, the vet who supplies the meds will know withdrawal times. I always figure five days for ace. Dorm is much shorter (2 days?) and a great help for heads and ticklish places. My favorite is a combo of ace(lasts longer) and dorm(makes them sleepier). Your vet may be reluctant to handle xylazine with the pending regulatory issues. Don’t feel guilty for sedating your horse to clip! It is kinder for Clipper and Clippee!

[LCDR]

I taught clinical pharmacology for 30 years but have been retired for a while. But looking at the pharmacokinetics of acepromazine versus xylazine and the research specifically done in horse models it seems that acepromazine is likely undetectable in plasma within 24 hours while there may still be enough xylazine metabolites remaining to be detected. Unless of course more sensitive analyses have been developed recently. I do not keep up with the latest publications.

[mroades]

ace tests for up to a week, just fyi
dormosedan is usually the safest both in practice and as far as testing goes.

[Ghazzu]

From “Acepromazine pharmacokinetics: A forensic perspective”
Veterinary Journal Volume 194, Issue 1, October 2012, Pages 48-54

“Acepromazine was quantifiable in plasma for up to 3 h with little reaching the urine unmodified. Similar to previous studies, there was wide variation in the distribution and metabolism of ACP. The metabolite HEPS was quantifiable for up to 24 h in plasma and 144 h in urine. The metabolism of ACP to HEPS was fast and erratic, so the early phase of the HEPS emergence could not be modelled directly, but was assumed to be similar to the rate of disappearance of ACP. However, the relationship between peak plasma HEPS and the y-intercept of the kinetic model was strong (P = 0.001, r 2 = 0.72), allowing accurate determination of the formation pharmacokinetics of HEPS. Due to its rapid metabolism, testing of forensic samples for the parent drug is redundant with IV administration. The relatively long half-life of HEPS and its stable behaviour beyond the initial phase make it a valuable indicator of ACP use, and by determining the urine-to-plasma concentration ratios for HEPS, the approximate dose of ACP administration may be estimated.”

[mroades]

I am not a vet. I am basing my statement on actual real world experience of showing and getting tested (colleagues have had horses test positive for ace used one week out, but not dorm 3 days out, when that is what they used) I do not claim to know the science behind it but I have experience as a trainer with horses who needed sedation for clipping or shoeing between shows.

I wouldyou talk extensively with USEF and your prescribing/administering veterinarian before using any sedative.

[LCDR]

Are we concerned about blood tests only? Or is urine also tested in horses?

[MHM]

Urine is usually tested if they can get a sample. It depends on how long the tester wants to wait around for the horse to cooperate. Blood is always tested.

[IPEsq]

Looks like in what was quoted above, at least 6 days for urine test for Ace. It has been a long time since I’ve been selected for testing, but way back then, they preferred urine if they could get it. I don’t recall blood being drawn in that case but the procedure may require blood now also.

[MHM]

For sure, they pull blood now.