Thanks to technological advances, there are more and more possibilities to make a good diagnosis in a horse when something is wrong. For example, a thermographic examination can provide more clarity about the complaints the horse has.
Thermography is an imaging technique that maps the body’s temperature by means of an infrared camera. The surface of a horse’s body emits infrared waves, which are not visible to the human eye. An infrared camera can detect these waves and converts them into an image, making it visible to us. When creating an image, a colour scheme and a temperature scale are used. It is common to show low temperatures in a darker colour (blue, purple) and higher temperatures in a lighter colour (yellow, red). Because you can take pictures with an infrared camera without the need to touch the horse, it can be an easy, cheap and painless method to use.
But what exactly can you use it for? In a healthy, stable situation the horse radiates an even temperature. It differs per area how high this temperature is, for example the legs of a (healthy) horse are colder than the head. This has to do with the degree of circulation to that body part. If something happens in the body, for example the horse injures its leg, something changes in this circulation. The injury causes the body’s immune system to kick in, sending extra blood to the damaged area. More blood and possibly swelling cause a higher temperature in that area. This increase can then be observed with the infrared camera. The body does not always have to react with an increase in temperature, it could also be that the temperature drops, for example with the formation of scar tissue, a decrease in muscle tissue or nerve damage.
On the basis of the images taken with the infrared camera, you can look for any deviations in the horse’s temperature. This is done with the help of special software. When analysing the images, it is especially important to look at symmetry. The left and right halves of the horse’s body should be of equal temperature. Is there a difference between left and right? Then there may be something wrong. By determining these temperature difference between the potential problem area and the surrounding tissues, you may have an indication of the seriousness and cause of the situation.
There are a number of factors to consider in thermography, otherwise the images may not be reliable. This is because temperature can be influenced considerably by environmental factors such as sunlight, wind and humidity. In addition, you must take into account use of rugs, work and touch. It is best to have your horse in a clean and dry stable for two hours prior to the thermography, of which at least one hour without any rugs, and to not touch the horse anymore. Taking that into consideration, the technique is reliable and solid according to the research. This study looked at the influence of camera position and angle on the results. This showed that the margins were broad, making it easy to apply. The research also showed that the method is extremely sensitive to the effects of wind and drafts. It should therefore always be performed in a windless environment.
A thermography does not provide a final diagnosis, but is a supportive diagnostic tool. It helps you to search in the right area. For example, in a horse that shows symptoms of lameness, the cause may originate in the legs, but also in the back. With the help of a thermography this quickly becomes clear and the correct treatment by a veterinarian or other specialist therapist can be initiated. Sometimes it may be necessary to have X-rays or an MRI scan taken to clarify the problem. In addition to back problems, there are many other conditions that can be revealed with the help of thermography. Think of hoof abscesses, joint problems, tendon injuries, dental issues and organ problems.