Digital infrared thermal imaging
Figure 1: Lateral thermograph of right hind limb.

Digital infrared thermal imaging provides an objective assessment of any integrated treatment plan.

Disclaimer: Dr. Ronald Riegel is a co-founder of Digatherm, a company that offers technologically advanced IR systems to the veterinary medical field.

The practice of integrated medicine focuses on the healing of the entire patient through multimodal therapeutic approaches. Digital infrared thermal imaging (DITI) provides an objective measurement, visually and numerically, of the progress, or lack of, at any point in the treatment plan.

What is Digital infrared thermal imaging?

Traditionally, subjective assessments are made that don’t provide a comprehensive evaluation of the patient. Phrases like: “He is now able to walk up the back steps.” “Today he is using his leg more than he has in quite some time.”  “I am palpating less swelling within the left stifle joint.”  These subjective observations are useful but don’t offer an accurate status of the patient’s whole well-being.

DITI provides non-invasive, objective, quantitative, and qualitative visual and numerical measurement of the physiological status of the entire patient irrespective of the multimodal therapeutic plan. In a matter of a few minutes, images can be captured that represent the physiological state of the patient at that exact moment. This is what is physiologically happening to the patient right now! This is in contrast to radiographic, ultrasonic, and MRI studies which tell us what has already happened to the patient. These images not only monitor and quantify the efficacy of the treatment plan, but will also detect any other areas in need of further diagnostics, serve as visual proof to the client the current status of the patient, and provide baseline data for future reference.

This visualization of the physiological state of the patient provides you with a “roadmap” to maximize your therapeutic plan and provides proof to the client of the efficacy of your treatment.  An educated client will be more compliant to further diagnostics, multimodal treatment approaches, and even more frequent visits.

Interpretation of the thermal images is not difficult. Any increase or decrease of  >1.0°C within the thermal symmetry of contralateral anatomical areas is significant. Areas depicting an increase (hyperthermic) or decrease (hypothermic) in thermal asymmetry require further evaluation and possibly further diagnostics. Areas of hyperthermic activity correlate to an inflammatory process, resulting in an increase in blood flow, whereas areas of hypothermic activity correlate to a vasoconstrictive state usually in response to a dysfunction within the sympathetic nerve pathway to the vasculature.

Digital infrared thermal imaging provides an accurate visual assessment and objective quantification of the clinical response of the patient. When clients are provided with a visualization of the progress of their pets, they have a better understanding and are more compliant to the individualized treatment plans.

Case study #1

Presentation: Feline patient with a history of a gradual reduction in activity.

A physical examination did not localize any sites of discomfort.  Digital infrared thermal images were captured utilizing a Digatherm 640 unit.

Interpretation of the thermal images

Both hind limbs (Figures 1 and 2) exhibited increases within the thermal gradients associated with the stifle joints. The left stifle revealed an increased hyperthermic asymmetry when compared to the right.  Interpretation indicates inflammation within both stifle joints.


In the right hind limb increases in thermal gradients were noted within the soft tissues radiating out from the stifle joint, particularly over the sartorius and biceps femoralis muscles (Figure 1). Indication of not only an inflammatory process within the joint but an illustration of the strain on the surrounding compensatory soft tissue structures.

In the left hind limb areas of hyperthermia were noted directly over the stifle joint and decreased in intensity as they radiate to surrounding soft tissues (Figure 2). Interpretation suggests a lesser amount of inflammation within this joint as the compensatory soft tissue structures surrounding the joint are exhibiting reduced areas of hyperthermic activity when compared to contralateral structures on the right.

After this visual representation of their pet’s physiological state to the client, permission was granted to do a radiographic study of both stifles.  This lead to a diagnosis of osteoarthritis.

tPEMF therapy was prescribed using the Assisi Loop.  This was done three times per day for one week, once per day the second week, and every other day the third week.

Digital thermal image re-evaluation:

Interpretation of thermal images:

After an interpretative analysis of the images:

The right stifle experienced a 91% decrease in the hyperthermic activity. Also, there was an increase within the thermal gradients throughout the distal limb. Interpretation: a decrease in inflammation within the original hyperthermic areas and a re-establishment of normal circulation throughout the distal limb.


The left stifle underwent a 96% decrease within all of the hyperthermic areas observed originally. There was also an increase within the thermal gradients associated within the phalangeal structures. Interpretation: a decrease within the inflammatory state of the stifle joint and the surrounding structures and a re-establishment of the circulatory pattern within the distal limb.


The treatment plan successfully reduced the inflammatory response within all of the hyperthermic regions and objective measurements are recorded to monitor this patient again in thirty days.

Clinically, the patient has regained movement that has not been observed in years.

Case study #2

Presentation: hind limb paralysis. Case contributed by Dominic Gucciardo DVM, CVA; Integrative Veterinary Therapies; Ridge, NY.

The initial dorsal thermal image (Figure 1) of the thoracolumbar area showed symmetrical and asymmetrical hypothermic activity throughout numerous vertebral and paravertebral segments. Thermal window of 73-92°F. Interpretation: this correlates to an asymmetrical irritation to the nerve supply to the vasculature in each anatomical region of interest.

Electroacupuncture of Bai hui, GV14, GV4, ST36, and BL23 was administered.


Eighteen minutes after electroacupuncture. Thermal window of 73-92°F.  Evidence of increases within all thermal gradients throughout image.  This is a visualization and a quantitative measurement of the re-establishment of the circulation within the regions of interest.

Twenty-eight minutes after electroacupuncture. The monitoring images (Figures 2 and 3) show progressive increases within the thermal gradients in the areas initially identified as hypothermic.  This indicates a normalization in circulation from re-establishment of neurological function following electroacupuncture.


Dr. Riegel earned his doctoral degree in veterinary medicine from the University of Illinois and has been the sole owner of a multi-doctor private practice for over 25 Years. He purchased his first therapy laser in 1979, first infrared thermography unit in 1987, and is the Co-Founder of The American Institute of Medical Laser Applications (AIMLA). Dr. Riegel has lectured both nationally and internationally on infrared thermography and laser therapy for the last two decades. He is the co-editor and content author of the brand new textbook, "Laser Therapy in Veterinary Medicine: Photobiomodulation", published by Wiley Publications.