Use of Thermography as a Diagnostic and Prognostic Tool in Selected Cetacean Conditions
The measurement of change in core body temperature, and its relation to infection or inflammation, is one of the oldest and most widely recognized diagnostic tools in medicine. The use of a thermometer is considered a basic part of the initial physical exam in most species and is often followed by other more sophisticated techniques to try to isolate the source of illness. With the development of affordable heat-sensitive cameras, the clinician can now detect general or specific areas of abnormal tissue temperatures. Detectable changes in temperature may be related to superficial tissue involvement or a reflection of heat production at a deeper level. These manifestations may include isolated or general areas involving such conditions as abscess, trauma, cellulitis, dermatitis, tendonitis, myositis, and pyothorax.
A thermographic camera was used in clinical cases in cetaceans to refine previous findings that indicated its potential applications in diagnosis and prognosis. Individuals which showed clinical signs compatible with trauma, dental disease, and dermal conditions were examined with an EVS DTIS-500 camera (Emerge Interactive, Sebastian, FL, USA) and therapy monitored with periodic thermal scans.
Dental disease including trauma to oral tissues, periodontal abscess, and mandibular infections could be readily located, temperature measurements taken, and the size of area of involvement noted. Post-therapy followup illustrated the ability to gauge the effect of therapy as evidenced by temperature decrease and a decrease in the size of the area involved. The clinician can also better determine the length of drug use based on the response. In one individual case it showed the infection from an abscessed tooth spreading down the lingual side of the mandible.
External trauma to the skin can be monitored for extent, complications and speed of resolution. Rake marks received from other dolphins have shown an inflammatory response present much longer than expected. A loss of normal temperature can also be used as a clue to the presence of material that may require debridement.
Dermatitis is currently being investigated for possible application of this technology. A Tursiops truncatus female with an extensive visual roughening of the skin showed substantial heat in the affected areas of the skin with thermography but no signs of inflammation on bloodwork. The skin inflammation was readily monitored by thermography until total resolution.