Digital Infrared Thermography: Is your Horse Hot or Not?


Digital Infrared Thermography is a non-invasive, quick proactive step to ensuring the best health for your horse. Digital thermography can be extremely useful in detecting issues such as compromised saddle fit, and subtle issues in the body BEFORE they become a major headache!

Recently I did a thermography scan of a horse who had surgery on his right front pastern over 18 months ago. We did a scan before and after riding. You could detect both times that there was much less IR energy coming off the affected leg even though he shows no lameness—thus he is apparently “using” the other leg more. Over time this could set this horse up for more injuries. I worked with this owner to come up with a home maintenance protocol to help stimulate circulation in this leg; she will also adjust her riding to emphasize strengthening that leg.

Similarly, last summer there was another gelding with lameness in his left fore. Even after blocking the vets couldn’t totally determine where it was coming from. I did thermography and bodywork and noted two things- he had increased IR signature below his left elbow, and there was a huge IR hot spot on his chest in a muscle that works to pull the shoulder forward (see image below). Sore, inflamed muscles wouldn’t necessarily show up on blocking test; likewise the owner then took the horse in for a more detailed bone scan and it turns out he had a fracture in the bone below the elbow- hence the increased IR signature. The IR thermography helped the owner make wise choices about how to spend her money on more diagnostics and thus led a “real” rehabilitation plan rather than just “laying off” for a short time.

Inflamed chest muscle.jpg

As a final example, two weeks ago I just did a much abbreviated thermography exam of a dressage mare who was having issues in her poll and TMJ. She had already had the TMJ injected, and the vet has discerned that she had old meniscal tears within the TM Joint. The current owner/trainer, who has owned her for a short time, has very sympathetic hands and rides beautifully, so the vet concurred this was all old stuff. Yet after treatment and time off there were still issues. I did a scan of the jaw and poll both before and after riding. What lit up like a Christmas tree were the hyoid structures UNDER the jaw—the basihyoid bone lies within the tongue and is connected through a series of small joints and bones into the TMJ and poll- but it is often overlooked.


The colors are a visible light interpretation of infrared radiant (IR) energy. Everything, and I do mean everything, reflects IR radiation. Thus, the settings placed on the camera "tuned" it, and in these images you are seeing images in a range between about 75-103 degrees (thermal range slightly varies between images). The single most important setting for capturing a true image is something called emissivity--this is basically a calibration you set the camera to that reads radiation based on the surface type. In this case, the emissivity was set to "skin", which has an emissivity value of .98. The closer the emissivity value is to 1.0 (considered a perfect IR radiator), the more you can trust what you are seeing to be accurate. Thus you get a very, very good reading on skin and very smooth coated animals like horses. The other thing to know is that I evaluate image quality while looking at the horse, taking images at several angles to ensure that "suspicious" warm areas that show there was not a reflection of energy radiating off a nearby object, like a wall. (If it is a reflection instead of true IR energy, it moves with you like a shadow).   Thus, the warmer spots in your thermography scan are all real, not reflected light artifacts. Many thermographers also are interested in COLDER areas too, as this can indicate lack of good circulation to an area.


 Don't be alarmed that there is some red on each image of a leg and heel bulb. I see the red vertical lines on the lower legs of horses all the time and much of this is in areas that are highly vascularized; what is more important to see are the differences between legs. Same is true with heel bulbs, they often appear bright red--note more differences between sides. What is more important is to look at the pattern between the two legs. It is not uncommon to have one leg be “redder” than another-- this can indicate that the horse was worked more on one diagonal, or that there is an imbalance. Sharing these images with your vet can be useful.


After images are taken, I process the images in special software and generate a report. This can be emailed to your vet, farrier, or saddle fitter. Thermography images, taken with proper skill to negate any false readings, are powerful, non-biased data on your horse’s condition. This data can be used to adjust saddle fit, shoeing, training regime, and home maintenance care.