Equine Infrared Imaging: Can it aid in detecting back pain?
Author: Ashley Teasley
According to published research, yes thermography is a valuable tool for aiding in the diagnosis of equine back pain. In 2006, a study done at Sao Paulo State University in Brazil proved that thermography used prior to ultrasonography was 100% effective for guiding researchers in making a diagnosis of back pain. 24 horses from three disciplines were used in this study. A physical examination was completed by veterinarians followed by a thermal scan of each horse and followed-up with ultrasonography of areas mapped from the thermal image. "Determining the exact location of the lesion and the cause of pain using physical examination only was not possible, although the pain could be determined as originating from the thoracic or lumbar region." (Fonseca, MS et al.) Interestingly, only three of the horses used in the study presented with existing lameness and in the other 21 horses the diagnosis of back pain was made BEFORE a lameness!
It wasn't just "hot spots" that lesions were found, but also cold spots. The diagnoses that were able to made were:
*dorsal intervertebral osteoarthritis
Based on the discipline of each horse they were also able to correlate a diagnosis:
*Cutting - 89% supraspinous desmitis followed by 44.4% dorsal intervertebral osteoarthritis *Barrel Racing - 63.6% osteoarthritis followed by 45.5% interspinous desmitis (lesions were unilateral, 62.5% occurred on the right side)
*Reining - 100% supraspinous desmitis followed by longissimus dorsi lesions at 50%. Furthermore, in 15 of the horses the number of hot spots indicated by thermography was the same as the number of lesions found. In the remaining nine horses the number of lesions found was higher than the number of hot spots indicated by thermography. In the case of kissing spines however, the lesioned areas presented no thermographic alteration whatsoever.
Does your horse exhibit training difficulties or behavioral problems yet resolving these challenges is proving to be difficult? 23 of the horses in the study done in Brazil were able to return to athletic performance and did so without clinical signs of back pain.
When observing thermal patterns of the equine back, or whole body for that matter, hot spots should not be the only focus, which is often the interpretation by the majority of people involved in equine care. "On the contrary, the author has found that chronic back pain cases usually involve cold regions at the affected sites...Chronic pain syndromes often involve persistent increased sympathetic nervous tone causing regionalized hypothermia from vasoconstriction. These conditions are NOT inflammatory diseases and therefore are unresponsive to anti-inflammatory medications." (Graf von Schweinitz, BSc, DVM, MRCVS). It is important to emphasize that while much can be ascertained from a thermographic image of the horse, it is not a stand alone imaging tool. Rather, thermography provides guidance, or a road map if you will, on where to focus further diagnostic imaging. Back pain is not the only case where thermography has been proven valuable in equine care, more to come!
*the attached images are in no way associated with any of the provided research. They are for attention purposes only.
Turner, DVM, Tracy A. “Diagnostic Thermography.” Veterinary Clinics of North America: Equine Practice. Vol 17. No.1. April 2001, pp 95-144. Science Direct, doi.org/10.1016/S0749-0739(17)30077-9. Accessed 3 November 2019.
Fonseca, MS, B.P.A et al. "Thermography and Ultrasonography in Back Pain Diagnosis of Equine Athletes". Journal Of Equine Veterinary Science, vol 26, no. 11, 2006, pp. 507-516. Elsevier BV, doi:10.1053/s0737-0806(03)00401-5.
Graf von Schweinitz, BSc, DVM, MRCVS, Dietrich. "Thermographic Diagnostics In Equine Back Pain". Veterinary Clinics Of North America: Equine Practice, vol 15, no. 1, 1999, pp. 161-177. Elsevier BV, doi:10.1016/s0749-0739(19)30009-4.