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Mac Robertson

So Mac Robertson is facing a potential 2 year suspension (and 25K fine) for a positive test here at Canterbury Park. The offending drug was altrenogest. What possible performance enhancement would there be for a gelding? He’s a 10K claimer. I’m thinking someone screwed up and gave him a dose meant for a mare. Or am I missing something.

Common for calming geldings same as when they were all getting depo on the show circuit. That said, even if it were a screw up it is still trainer responsibility rule makes him still liable.

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I get that, he’s the responsible party. And I know why that rule is in place.

progesterone for calming just seems a weird choice to me…

Edited to add: I guess it is known to have some sedative effects…

The problem is the drug is banned in racing. It shouldn’t be able to be given to the wrong horse because it shouldn’t be anywhere on the backside.

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Regumate is banned? Wow that must be fun for wildly cycling mare owners.

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Sorry, I was wrong. It’s prohibited for use in geldings, intact males, and spayed mares.


I see you corrected below. Yes, this is why I think it is possible for a misdosing to occur. Lots of mares run on it. That in no way excuses it being used in a gelding, especially given the reported calming effect.

I posted initially more informationally. This is a big change at Canterbury. A year ago, this would have resulted in loss of purse and a 1000 fine. Now he faces a 2 year suspension and 20K fine.

Don’t get me wrong, I am for zero tolerance when it comes to drugging performance horses. I wish other disciplines would follow. Drives me nuts that barrel racers commonly give guanabenz and reiners have a legal amount of romifidine they can give. The only drug rule for barrel racers is that the rider can’t be intoxicated!


Is this a first offense or just the latest for this trainer? 2 years is pretty stout.

Just read a better article. Looks like he could get “up to 2 years”. I’m guessing he gets much less when they make the final decision. His record is not spotless. He had NSAID overages 10+ years ago and one positive for meth in 2015. He fired two of his employees after the meth incident.