Monday, July 18, 2011

Blasted Hot and Cryptorchid Tests

At 6 a.m. it's already 80 degrees F, relative humidity over 80% and a heat index of 87, and we're heading to a high in the mid 90s with a heat index over 105.  Since our pastures have not a shred of shade, that means horses are out at night and in during the day under their fans.  I've been taking my horses out about 9 p.m. and then going over around 5 a.m. to bring them in and feed them breakfast and then turn then back out again with some fresh fly spray for a few more hours of grazing.  Then I bring them in between 9 and 10 a.m.  This heat will be going on until at least the weekend.  Tomorrow's supposed to be a bit cooler, so I'm hoping to get a ride in on Pie tomorrow morning.

This morning the vet is coming to do some blood tests on Drift to once and for all determine if he's a cryptorchid or not.  As many of you probably already know, a cryptorchid is a male horse with either one or two testicles retained in the body.  These retained testicles produce testosterone, leading to stallion-like behaviors, but such horses are usually not fertile because of the temperatures inside the body being too high for viable sperm.  Apparently this condition does occur with some frequency in QHs, and it also tends to run in certain lines so there's probably a genetic component.  Here is a good article on the condition.

We're doing two separate hormone tests.  The first is two blood draws for testosterone.  The first one is for baseline testosterone - cryptorchids usually have a higher baseline testosterone than geldings although there's a wide range.  Then the vet administers some human chorionic gonadotropin (hCG), waits a period of time and then does another blood draw for testosterone - if the horse has retained testicular tissue, the testosterone levels will rise whereas they will not go up if the horse is a true gelding.  This test has about a 95% accuracy.  Since the vet's doing blood draws anyway, we're also testing for conjugated estrogens, which are also higher in horses with testicular tissue - this test also has about a 95% accuracy.

I'm still inclined to think that he isn't a cryptorchid, but rather just a studly gelding, but the tests will give us better information for a fairly minimal cost.  He does exhibit a lot of stallion-like behaviors, which intensify when the mares are in heat.  He makes stud piles of manure to mark his territory on the fence lines near the mares, he herds the other geldings away from the mares, and he's obsessively interested in the mares - nickering, calling to them if they're nearby and screaming for them if they aren't.  He's also quite the alpha with the other geldings although he's by far the littlest horse in the herd.  His behavior with a newly introduced gelding can be quite aggressive.  But then once past the introduction stage, he's quite accepting of the other geldings if they're not near the mares - standing and grazing together with them and engaging in mutual grooming.  He's never shown much if any overtly sexual behavior even when the mares are in heat and I'm able to ride and handle him near mares, although it does take some care to keep his attention on me.  He's also not aggressive with people and isn't mouthy or nippy with people at all - this picture captures his basically very sweet and curious personality:

If he turns out to be a cryptorchid, we'll have the offending object(s) surgically removed, both to improve his behavior and also because cryptorchids are at higher risk for testicular cancer.  There is now a laparoscopic surgery for this which has a much shorter recovery time, and I expect one or both of the vet clinics within an hour or two of us will have this available.  If he's not a cryptorchid, then we'll just continue on with our training - I've been working with him as if he were a stallion - that's to say working with him just as I would any other horse and expecting the same from him as from any other horse.

I don't know which outcome I'd prefer - if he's a cryptorchid and we do the surgery, he will be even easier to work with and he's already a fine little horse - if he's not then we just keep on with our training and save the cost of the surgery . . .

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