Use of Thermography for Functional Evaluation of Stallion Scrotum and Testes

•Thermography used to determine optimum stallion testicular temperature gradients.•Ten stallions produced 85 semen collections for analysis.•Testicular temperature before collection analyzed against end motility score (MS).•Strong correlation between optimum testicular temperature and high MSs.•Thermography provides noninvasive means to assess early subclinical factors

The aim of this study was to assess whether correlations could be made between the temperature of stallion testes, before collection, and the motility score (MS) rating given to the subsequently collected ejaculate. Thermography was used as a noninvasive means to image the scrotal surface temperature. The collected thermograms were analyzed, first, to establish a thermal gradient “norm” or “optimum range” (OR) of a testis and, second, to establish whether a relationship could be found between testicular temperature immediately before semen collection and the MS of the semen subsequently collected. The study involved 10 stallions giving 85 semen collections over two collection sessions, autumn 2011–spring 2012. The study found an apparent association between stallions that conform to the OR and greater MS ratings. Based on the results, it is concluded that thermography could be used as a monitor to provide a noninvasive indication of subclinical testicular factors that may affect a stallion's fertility and provide an early indication that further veterinary investigation may be required.