Equine Digital Thermal Imaging

Have you ever thought your horse was a little off, or a bit grouchy in his work? Or that something was just not quite right – you thought that he was hurting or sick but you, and maybe even your veterinarian could not find a reason? Well this scenario is not uncommon. YOU know your horse better than anyone. As veterinarians we can only diagnose what we can identify, and our imaging modalities (radiographs and ultrasound) can only ‘see’ when there is anatomical disruption or change. Blood work is helpful, but there are generous ranges for normal values, and patients with problems can have relatively normal blood values.
 
Wouldn’t it be nice if we had the ability to do a physiologic (body function) exam that was reasonably priced and noninvasive? One that would catch these injuries before the anatomical disruption or change? YES! And we do. I want to share with you the science of Digital Thermal Imaging (DTI). I’m going to channel Bill Nye, the science guy for a minute here… Thermal imaging is based on the scientific principles of electromagnetic energy. This is a type of energy that is either emitted or reflected by objects and travels through space as waves (electrical or magnetic). This includes radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, etc. The name of wave is defined by the length of the wave. Any object with a temperature greater than absolute 0 emits infrared radiation), a wavelength too long to be seen by the human eye and felt as heat. It can be recorded specialized infrared cameras forming a thermogram, and this is what we are interested in for medical thermal imaging.
 

 
Our new digital thermal imaging system is state of the art and identifies temperature changes of less than 1 degree. Even an experienced veterinarian’s hands can not appreciate temperature variation until there is a 3-4 degree difference, often by this time there has been an ongoing inflammatory process for weeks. Research has shown that thermography can identify areas of injury up to 3 weeks before the horse exhibits clinical signs. This is especially important for competitive horses where early identification and care can prevent time lost from competition or training. A mild inflammation in a tendon or ligament can be identified, and treated before it becomes a career threatening defect. Muscle injuries are notoriously difficult to identify and can take months to heal, but the thermal change can be measured with the DTI, and response to treatment can be evaluated so the horse is not returned to work too early.
 
We are not only interested in an increase in heat. Cooler areas are also important and can indicate nervous system dysfunction, scar formation, swelling or thrombosis. Other areas in which thermography is useful include evaluations of hoof balance and saddle fit. Thermal imaging is a great noninvasive addition to your horse’s annual exam. Injury prevention is always less expensive and better than treatment! 