Page 113 - September 2016

they weren’t necessarily concerned about the NSAIDs,” says Mays.
“That was the reason we decided to offer this independent tranquilizer screen. Since then, we’ve received client feedback about possibly adding some other drugs that contain those same sedative and tranquilizing effects in horses. As a result, we’ve recently added three more drugs: acepromazine, guanabenz, and romifidine. We will have all six of these drugs as part of our tranquilizer drug screen,” he says.
“As far as drug testing goes, our primary focus is to establish a level playing field— whether in horse racing, or other competitive events like barrel racing.” Also, if someone buys a horse, whether for performance in a certain sport or just for pleasure, they want to know if the horse is sound and whether they are getting what they see.
“We want to help make sure the animal is sound, not only to protect the horse, but also to protect the person who potentially will be riding or handling that animal. That’s the basis of the testing we do,” he explains.
Liquid or gas chromatography/mass spectronomy drug testing, or instrumentation testing, is highly sensitive, efficient, and can check for a number of drugs in a single test.
The Testing
“The way we conduct our testing, any sample we report as positive has been tested twice. Every sample that comes in the door goes through an initial screening process based upon which drugs we are targeting. The sample is screened and, if it appears to be positive or what we conclude is suspicious, we go back to the original sample container and repeat the process. This second time, however, we use specific positive and negative controls for the targeted drug that was identified or flagged during the screening process. This way, we can double check and make sure. This is what we refer to as our confirmation test,” says Mays.
“Most of the tests we do in our lab here in Texas are for the racing industry. The Texas Racing Commission is our biggest client. We do drug testing year-round for that industry. However, we are also very involved with the
show industry and we do drug testing for more than 60 shows in state and out of state - testing the animals, including horses that go to these show events. It’s similar to the horse racing in terms of the drugs we are screening for, but there’s some variability,” he says.
The third category of testing is what TVMDL does for veterinarians, looking at diagnostic samples. “These would include
the equine pre-purchase drug screen. That
one is probably our most popular test, but I
am hoping our new test will give clients some flexibility. They won’t necessarily test for the NSAIDs if those are not a concern. Having this new test just for the tranquilizers will be of some benefit,” says Mays.
On a pre-purchase exam, in some instances you might want to know if the horse has
any drugs on board. “Some drugs might be masking a lameness or a horse that might
be crippled. Tranquilizers might change the behavior of a high-strung horse, calming the animal,” he says.
“Probably less than 1% of the samples
we test annually actually are confirmed as positives, but those are the ones we need to find,” he says These might have been used intentionally to keep a horse from being lame or “off” during a show, or there might be some residue still in the body from a drug that was used earlier for another reason.
“All drugs are different in their pharmacokinetics and how they are absorbed, distributed, metabolized, and excreted. So, they vary in the length of time it takes for them to be eliminated from the body. And just like humans, every animal is different in how they metabolize and excrete those drugs, so there is a lot of variability,” explains Mays.
“Another thing to consider is that technology is always changing. It’s been interesting to see, from my vantage point, how over the last 5 years there has been a change in the technology we have, from an instrument standpoint. The testing we are doing is much more sensitive than in the past. With some of these drugs, we now have the ability to test down to parts per trillion,” he says. This would be an amount so minute that it wouldn’t be affecting the horse at all.
“Therefore, there are some drugs you might question if we did find them at a trace amount, whether that small amount of the drug would have any physiological influence in the animal. We can’t answer that question, but clients need to be aware that we do have the ability to detect certain drugs at much lower levels than we did 5 or 10 years ago,” says Mays.
“There have been some cases within the last couple of years in which some people in the equine industry have felt the effects of
the sensitivity we are testing at now. It can be problematic if people are not aware of how low we can go in finding these drugs.” When competing in disciplines, like racing, that prohibit drug use, a person would have to be sure they hadn’t used anything in those animals within a certain time frame.
“We primarily test urine and blood in
all the animal species we look at. But for the equine pre-purchase drug screen and this long-acting tranquilizer panel, we prefer to have serum from blood. It gives us the best opportunity to see what might have been administered to the animal or see what’s in that animal’s system within the last 48 hours, depending on the drug,” says Mays.
The turnaround time for both of those
tests is 1 to 3 business days. “This difference
is based upon the difference between the screening and confirmation. If we screen a sample and it comes up negative and is not deemed suspicious, typically we will have the results the following day - and sometimes the same day. If the sample appears to be suspicious
If a sample appears to be positive or suspicious, the original sample is tested again.
and we have to go back and re-test it, the report will probably be generated and submitted to the client on the third business day,” he says.
“Ideally, we’d like to have a minimum of
5 cc of serum for the sample. This allows us
to screen for all those drugs, and to repeat
the process and re-test and do confirmation testing if we need to. That’s the beauty of this technology. It allows us to screen for many drugs at one time, in each sample. It also allows us the flexibility to add, and/or remove, drugs from a particular screen - just like these 3 new ones we are adding to the tranquilizer panel,” he explains.
“If we get enough feedback and clients
are really interested in additional drugs, we can get those added. The technology and the instruments we have today allow us to do that. We just need to know what our clients want,” he says.
“Being in the diagnostic lab and this side of the business, we don’t get much feedback.
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equine health