COMPARISON OF CURRENT METHODS FOR THE DETECTION OF CHRONIC MYCOPLASMAL URTD IN WILD POPULATIONS OF THE MOJAVE DESERT TORTOISE (GOPHERUS AGASSIZII)

Abstract Pathogens that cause subclinical diseases or exhibit low infection intensities are difficult to quantify in wild populations. Mojave desert tortoises (Gopherus agassizii) have been the focus of much research aimed at measuring the presence of upper respiratory disease (URTD) and URTD-associated pathogens, and techniques used to quantify disease in Gopherus species have also been used for disease surveillance in other species of turtles and tortoises of conservation concern. Published surveys of G. agassizii populations have found a relatively low prevalence of URTD, with most URTD-positive animals exhibiting moderate, intermittent signs of morbidity. Therefore, multiple tests have been developed to quantify URTD including genetic detection of the pathogens Mycoplasma agassizii and Mycoplasma testudineum, detection of M. agassizii-specific antibodies, and standardized quantification of clinical signs of URTD and body condition. These diagnostic tests have only been compared in diseased or moribund...