Largely because any heat produced would be as a result of his own body and muscles.
(Moon, before being ridden. We can see the marks left by his girth (I think the dirt was clinging to the cooler areas since he was let out yesterday still damp). We can see a mark where my calf would have rubbed just behind the girth marks. We also see some heat in his lower back, which we'll examine further).
We looked at all of his hooves before exercise and it was pretty uninteresting. His hooves were relatively cool, he had no abnormal heat signatures on his legs (all heat was uniform in pattern, and therefore from blood flow), and his back was relatively uninteresting as well. We saw some minor increases in heat where his rain sheet was rubbing around his neck, as well as heat where his winter blanket had taken the hair off his chest.
(Stock image of uneven heat signature in hoof)
(Stock image of even heat signature in hoof)
(We see even heat in Moon's hooves post-exercise. Yellow patches were all sand stuck to his hooves!)
(Again, uniform heat signatures. This time, pre-exercise so they're cooler. The heat in his legs was uniform on both sides).
I saddled him up and went for a 15 minute ride of walk-trot-canter (screw leads) around the arena to warm up his back and body. The intent was to look for abnormal or inconsistent heat signatures on his saddle panels, so he was ridden with no pad between his back and the saddle.
I rode him straight back into the barn, we shut the door to keep the drafts out (wind, not the horse), and infrared'ed him.
From there, we captured images of the panels of his saddle. THIS was pretty interesting...
(Stock image of proper fitting saddle)
(Moon's saddle. As you can see, pretty uniform heat across all panels (our color range is set a little higher then the stock image, so more white patches).
(Again, nice uniform heat across all panels.)
We also captured numerous images of his back and using the laser pointer built into the camera, were able to pinpoint exact heat spots.
(Heat spots over his back where the rear panels of the saddle sit. Note slightly more heat on his right then left side. Image is looking towards his rump).
(Same back showing heat from rear panels, looking towards Moon's head this time)
(Again, looking towards Moon's head. Slight cool spot on his left side (bridging), and extra heat on the rear right panel).
We saw very little excess heat from his shoulders, and the obvious increase where my calves had been on his sides. Ditto for my butt and legs in the saddle.
(You can see where my calf rubs. Interestingly, this same spot was hot (even to touch) BEFORE he was saddled and ridden. Perhaps left over from my leg rubbing during our gallop yesterday??)
The images of interest??
For starters, the back of his saddle panels are pressing on his back. I had seen some rubbing in these same locations when he was being ridden in the cotton pad a month ago (and some hair loss), and in the infrared we could easily see high heat spots in these areas.
(Hot spot on back panels, showing cooler down spine (to left of image)).
His hooves had all warmed up with the exercise, but overall they all had the same heat patterns. There was a bit more heat in all of the grooves, leaving me a little suspicious about some premature thrush growth in the areas.
(Right fore hoof, with suspected bruising/abscessing. Not that there's more heat on the one side of the hoof. Heat around the frog was consistent in all hooves, after exercise).
The only other thing of note was his hind right cannon, which had a small patch of high heat. It was just around where he had that swelling last summer that had him lame for a week, and it only appeared after exercise.
(Looking toward's Moon's rump at his hind legs. Note the heat spot on his left cannon).
(Closer view of the heat spot).
This is also the leg that the farrier thought he had been sore on.
I suspect that he's probably got some chronic, long term issues with the tendons on this leg, probably confirmational in origin (let's face it, he does toe out a bit).
(Moon, under saddle. Note that we can see the increased heat along his back).
(Me, Moon and a barn cat. Yes, he climbed up there. Guess everyone wanted to be imaged!)
(All stock images thanks to: http://www.veterinary-thermal-imaging.com/) (All of Moon's thermal images thanks to my awesome BF!).
We'll get into that tomorrow. And apparently, I'll also cover off how freakin' awesome the BF is...cause he wouldn't stop complaining if I didn't promise that... : P