Contents lists available at ScienceDirect Journal of Thermal Biology journal homepage: www.elsevier.com/locate/jtherbio Monitoring changes in body surface temperature associated with treadmill exercise in dogs by use of infrared methodology Maria Rizzo a , Francesca Arfuso a , Daniela Alberghina a , Elisabetta Giudice b , Matteo Gianesella c , Giuseppe Piccione a, ⁎ a Department of Veterinary Sciences, University of Messina, Polo Universitario dell’Annunziata, 98168 Messina, Italy b Department of Animal Medicine, Productions and Health, University of Padua, Viale dell’Università ̀ 16, 35020 Legnaro, Padua, Italy c Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 S, Agata- Messina, Italy ARTICLE INFO Keywords: Dog Exercise Infrared thermography Infrared thermometry Body surface temperature ABSTRACT The aim of this study was to evaluate the influence of moderate treadmill exercise session on body surface and core temperature in dog measured by means of two infrared instruments. Ten Jack Russell Terrier/Miniature Pinscher mixed-breed dogs were subjected to 15 min of walking, 10 min of trotting and 10 min of gallop. At every step, body surface temperature (T surface ) was measured on seven regions (neck, shoulder, ribs, flank, back, internal thigh and eye) using two different methods, a digital infrared camera (ThermaCam P25) and a non- contact infrared thermometer (Infrared Thermometer THM010-VT001). Rectal temperature (T rectal ) and blood samples were collected before (T0) and after exercise (T3). Blood samples were tested for red blood cell (RBC), hemoglobin concentration (Hb) and hematocrit (Hct). A significant effect of exercise in all body surface regions was found, as measured by both infrared methods. The temperature obtained in the eye and the thigh area were higher with respect to the other studied regions throughout the experimental period (P < 0.0001). RBC, Hb, Hct and T rectal values were higher at T3 (P < 0.05). Statistically significant higher temperature values measured by infrared thermometer was found in neck, shoulder, ribs, flank, back regions respect to the values obtained by digital infrared camera (P < 0.0001). The results obtained in this study showed that both internal and surface temperatures are influenced by physical exercise probably due to muscle activity and changes in blood flow in dogs. Both infrared instruments used in this study have proven to be useful in detecting surface temperature variations of specific body regions, however factors including type and color of animal hair coat must be taken into account in the interpretation of data obtained by thermography methodology. 1. Introduction The homeothermic animal establishes an equilibrium between heat production and heat loss in order to maintain a constant temperature (Arfuso et al., 2016b). The body produces continuously heat that is dissipated though the surface in several ways (Piccione et al., 2005). It is well established that the body temperature exhibits an endogenous daily cycle (Refinetti and Piccione, 2003). Physical exercise represents stressful stimulation which can lead to homeostasis disruption with direct impact on animal health status and physical performance of the animal (Arfuso et al., 2016a). The evaluation of body temperature re- presents a valuable tool to monitor the physiologic status, welfare and the stress responses of animals. Exercise induces the conversion of stored chemical energy into mechanical energy and thermal energy; this process is relatively inefficient and about 80% of the energy released from energy stores is lost as heat (Rizzo et al., 2017). The control of heat exchange between body surface and external environ- ment plays a very important role in regulation of body temperature during exercise (Casella et al., 2016). Generally, body surface tem- perature was estimated by averaging values of the temperature re- corded in predetermined regions of interest by means of finite contact temperature probes including resistance thermometers and other types of thermocouples applied to the body surface (Fernandes Ade et al., 2014; Piccione et al., 2013; Matsuo et al., 2006; Eddy et al., 2001). In recent years, infrared thermography has been suggested as useful tool both in the diagnostic field and in physiological assessments (Rossignoli et al., 2015; Redaelli et al., 2014; Ring and Ammer, 2012). In contrast to core temperature measurements through rectal sensors, perceived as invasive and discomfortable for the animals, the infrared methodology represents a non-invasive way of measuring body surface temperature http://dx.doi.org/10.1016/j.jtherbio.2017.06.007 Received 30 March 2017; Received in revised form 16 June 2017; Accepted 21 June 2017 ⁎ Corresponding author. E-mail address: giuseppe.piccione@unime.it (G. Piccione). Journal of Thermal Biology 69 (2017) 64–68 Available online 22 June 2017 0306-4565/ © 2017 Elsevier Ltd. All rights reserved. MARK