History of Vet Thermography

Thermography in Veterinary Medicine

By Miriah Stuart

 
Hippocrates was a famous, bright, and intuitive physician.  He was born in Greece, circa 460 B.C., and in his life’s work he discovered that mud, when applied to the human skin in a thin layer and allowed to dry, would show him areas of heat and inflammation on the body’s surface.  This allowed him to detect where there were problems in the patient.   

Left front leg of border collie pup, much hotter from toe to armpit than other side

 

Technology has come a long way, baby, and modern science now gives us thermography, or infra red imaging, to see the temperatures radiating off the surface of the body.  It is being used in human medicine, breast imaging, equine, canine, wildlife, zoo and marine mammals, and anywhere else someone can think to use it.  It is an amazing camera, and can show inflammatory and physiological changes that help us understand where the animal has issues.  It is a tool to help us answer “where” questions.

In this country, there are some outstanding pioneering veterinarians using this technology as another tool to assist them in diagnosing injuries and disease.  In February 2010, four doctors and a saddle fitter presented a thermal imaging seminar at the University of Florida College of Veterinary Medicine.  I was fortunate enough to be one of the students of this talented and passionate group. 

This article will give you a brief history of thermography, why it’s not more popular with vets, what the technology is, and how it is being used today to help animals and veterinarians.

History

Infra Red sensing devices were first developed by the military for use in World War II.  In 1964, Dr. Smith experimented with thermography to image horses, but it took six minutes to create an image.  It was determined in a 1965 study by Dr. Delahanty that until instrumentation was improved, thermography was not practical in equine applications. It simply took too long to create an image. (That was 45 years ago.)  By 1973, technology had improved, and Dr. Stromberg was successful in evaluating tendon damage in the horse.  In 1976, Dr. Fredricson took thermal images of horses running on racetracks to study the designs and angle of the turns to determine if there was a better way to design a racetrack – one that caused less inflammation and injury.  In the mid 1970s, vets were using this technology to discover damage done to horses at the hands of humans, and it became an advocate for the horse as an imaging tool to enforce the Horse Protection Act.

Why thermography isn’t more popular

As the technology improved in the 1980s, veterinarians could see the benefits of having thermal images of their patients.  The cameras were still very cumbersome and slow, needed to be cooled, and had to be cabled to the monitor to see the images.  They were also terribly expensive.  Not many clinics could justify the purchase, and the return on investment didn’t really pencil out.  At the same time, diagnostic ultrasound technology was becoming more important, and scintigraphy technology was improving as well.  These methods gained popularity and the thermography camera did not.

What is thermography?

Thermography is a physiologic imaging device.  This means that instead of looking at anatomy, like radiograph (X-ray) and ultrasound images, we are looking at the surface of the skin and the heat and cold that is radiating off the skin.  The thermography camera measures these temperatures and displays them in a rainbow palette.   

 
 
 

Hind leg of horse, much more heat than other legs. This is not a normal thermal pattern.

In radiographs and ultrasounds, we are looking at the anatomical structures of the horse – the bones, tendons & ligaments.

  In a physiologic image (thermography and scintigraphy) we are looking at the metabolic activity and changes taking place in the patient.  According to Dr. Tracy Turner, and Dr. James Waldsmith, “Tendons and joints will show inflammatory changes up to two weeks before clinical lameness is apparent.”   Inflammation shows most often as heat in the image.

Heat and inflammation are not the only part of the image that the doctors are looking for.  A cold area on the thermal image can indicate that the blood supply to the area has been damaged, or there has been disruption to the nerves that supply that area of the body.  According to Dr. Turner, “sometimes the thermal images create more questions than answers.”

What thermography is being used for today

As the technology and image quality have improved over the years, more vets are combining physiologic imaging (thermography) with other diagnostic imaging to make a better diagnosis. 

Thermography was used at the Atlanta Olympics and the Olympics in Seoul Korea by doctors to evaluate the horse’s health in the extreme summer conditions.  Dr. James K. Waldsmith, of San Luis Obispo, CA – one of the presenters at the University of Florida seminar – was at the Atlanta Olympics helping the horse athletes.  Dr. Waldsmith’s website is www.VetelDiagnostics.com  You can look for upcoming training opportunities here.

Dr. David Marlin of England, a leading expert on equine exercise physiology, has used thermography in studies of equine boots made with neoprene to help invent a cooler boot for the horse’s protection while training and competing in cross country jumping and three day events.  Dr. Marlin was also part of the medical team at the Atlanta Olympics, as well as the Seoul, Korea Olympics, and has co-authored the book Equine Exercise Physiology. For more information, visit www.DavidMarlin.co.uk

Dr. Tracy A. Turner, of Minnesota, is a pioneer of thermography – using it since the 1970s – and has been on the teaching staff at the University of Florida, along with other vet schools.  He is using thermography along with anatomic imaging in his equine practice.  He is passionate about teaching this technology, and I am grateful to him for his contribution and desire to teach this. For more information, click here to go to his website

 Dr. Mike Walsh, professor at the University of Florida, College of Veterinary Medicine was the program organizer.  He is using thermography to help the marine mammals in his care.  When he took images of the wrists of a seal that performed in a show, Dr Walsh was able to show the trainers that the seal had inflammation in the corpus region, and suggested a rest period for the animal.  Thermography was again employed to see when the inflammatory process was complete and the seal returned safely to work without re-injury.  This is wonderful for the animals.

  

Aussie dog, 14 years, injured right front leg. Heat shows red in the image.

In Utah, Dr. Kimberly Henneman is using thermography to see injuries and disruptions to agility dogs, working dogs, and sled dogs, and has been able to assess where dog harnesses are rubbing the shoulders of these dogs.  She utilizes thermography to detect back injuries, and tendon and ligament injuries.  After presenting the canine portion of the seminar, she was leaving Utah to attend the Iditarod Sled Dog race in Alaska. Click here to go to her website.  

 
Mike Corcoran, of Texas, is a saddle fitter and maker of fine dressage saddles.  He is a dressage rider as well.  He uses the infra red camera to take images of a horse’s back, the saddle itself after being ridden, and with these images, helps his clients get the best fit for the horse. He is also passionate about protecting horses and educating riders.
All of these professionals are hard working, and dedicated to the animals they serve.  It was a pleasure to be in their seminar, and take away so much information.

 Thermography is best described as a “where” tool.   It can assist the vet and saddle fitter in knowing where to look further.  As both Dr. Waldsmith and Dr. Turner say, “A thermal image will show us what we didn’t know we didn’t know.”   And both doctors are convinced that by combining both physiologic and anatomic imaging, this helps them reach the most definitive diagnosis.

This article was first published in Flying Changes Magazine, April 2010 issue.

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