Applicability of thyroxine measurements and ultrasound imaging in evaluations of thyroid function in turtles

Abstract

Introduction: The thyroid and parathyroid glands play a major role in maintaining physiological homeostasis in all vertebrates. Reptiles have plasma concentrations of thyroid hormones far lower than mammals. Low levels of these hormones in reptiles impede thyroid hormone detection with assays designed for the higher levels of mammals. The aim of this study was to explore teaming this with ultrasound imaging of the thyroid to appraise glandular function. Material and Methods: Thyroid function of four pond sliders was evaluated based on the results of T4 analyses and ultrasound. Results: The concentrations of T4 varied considerably between the examined animals from <9 nmol/L to >167.3 nmol/L. Ultrasound examination revealed uniform echogenicity and a smooth outline of the thyroid gland in all animals. Conclusion: Monitoring of thyroid function based on T4 and electrolyte concentrations is helpful in assessing the health and living conditions of reptiles, which is important in veterinary practice but problematic. Ultrasound examinations are useful in diagnosing changes in gland structure, such as tumours and goitres, and a combination of both methods supports comprehensive assessments of the anatomy and function of the thyroid gland.

Morphometric descriptive report of scleral ossicle rings, by ultrasound and computed tomography, in three Testudines specimens

“…Non-invasive imaging exams (US and CT) were performed to describe scleral ossicle rings in three live species of Testudines. These diagnostic techniques have proven useful in the study of reptile anatomy (PAJDAK-CZAUS et al, 2019;PAULINA-CARABAJAL et al, 2019). The morphological knowledge of associated ocular structures is fundamental for ophthalmology and is important for the distinction between taxa, age estimation and activity patterns of animals -once there is a close relationship between eye and orbit dimensions, and between these and scotopic or photopic activities of species (FERNÁNDEZ et al, 2005;OLIVEIRA et al, 2008;SCHMITZ & MOTANI, 2011).…”

“…Imaging morphobiometric studies are important for in vivo descriptions and have already been used for the anatomical evaluation of celomatic cavity of Testudines (C. carbonarius, Testudo hermanni and Trachemys spp.) (MEIRELES et al, 2016;PAJDAK-CZAUS et al, 2019). Similar analyses have also been performed for endocranial evaluation of fossil Testudines (Naomichelys speciosa, Galianemys emringeri, Galianemys whitei, Nichollsemys baieri and Hamadachelys escuilliei) and living animals (Trachemys scripta elegans and Malaclemys terrapin) (WILLIS et al, 2013;PAULINA-CARABAJAL et al, 2019).…”