Identification of Uric Acid Crystals Accumulation in Human and Animal Tissues Using Combined Morphological and Raman Spectroscopy Analysis

Gout is a metabolic condition, common to animals and humans, issuing from the excessive accumulation of end products of proteins degradation. In this study, histopathological and cytological examinations, combined with Raman spectroscopy, have been performed to investigate tissue samples from reptiles, chickens, and humans, presenting lesions produced by uric acid accumulation. As a result of classic processing and staining techniques commonly used in the anatomopathological diagnosis, uric acid crystals lose their structural characteristics, thus making difficult a precise diagnostic. Therefore, complementary diagnostic methods, such as Raman spectroscopy, are needed. This study compares from several perspectives the above mentioned diagnostic methods, concluding that Raman spectroscopy provides highlights in the diagnosis of gout in humans and animals, also adding useful information to differential diagnosis of lesions.

Symmetrical Dimethylarginine as a Diagnostic Parameter in Hermann's Tortoises (Testudo hermanni)

Background

Despite improvements in habitational conditions, kidney disease is relatively common in tortoises.

Objectives

Purpose of this study was the establishment of Symmetrical dimethylarginine (SDMA) reference values for clinically healthy Hermann's Tortoises.

Animals

Clinically healthy Hermann's Tortoises (n = 131) were included in the period from October 2017 to September 2019.

Methods

Creatinine and other biomarkers were tested at IDEXX Laboratories, Germany using residual blood samples from Hermann's tortoises. SDMA was measured with the IDEXX test and verified by liquid chromatography-mass spectrometry at IDEXX Laboratories, USA.

Results

SDMA values ranged from 1 to 21 μg/dl (n = 131) for the IDEXX SDMA Test and SDMA values ranged from 1 to 17 μg/dl (n = 82) for LC-MS. For the comparison of the two measuring systems, the following results were obtained R² = 0.75 (p < 0.001).

Conclusion and Clinical Importance

SDMA can be measured in Hermann's Tortoises and the reference values range in clinically healthy animals is comparable to that of dogs and cats.

PLASMA BIOCHEMISTRY PROFILES OF WILD WESTERN TIGER SNAKES (NOTECHIS SCUTATUS OCCIDENTALIS) BEFORE AND AFTER SIX MONTHS OF CAPTIVITY

Urban wildlife often suffer poorer health than their counterparts living in more pristine environments due to exposure to anthropogenic stressors such as habitat degradation and environmental contamination. As a result, the health of urban versus nonurban snakes might be assessed by differences in their plasma biochemistries. We compared the plasma profiles of western tiger snakes (Notechis scutatus occidentalis) from a heavily urbanized wetland and a natural, nonurbanized wetland. Despite the urbanized snakes having lower body mass index, we found no significant difference between the plasma profiles of the two populations. We collected snakes from each population and kept them in captivity for 6 mo, providing them with stable conditions, uncontaminated (exempt from heavy metals and pesticides) food and water, and lowered parasite intensity in an attempt to promote better health through depuration. After captivity, snakes experienced a significant improvement in body mass index and significant changes in their plasma profiles. Snakes from the natural wetland initially had more variation of DNA damage; mean concentration of DNA damage in all snakes slightly decreased, but not significantly, after captivity. We present the plasma biochemistry profiles from western tiger snakes both before and after captivity and suggest a period of removal from natural stressors via captivity may offer a more reliable result of how plasma profiles of healthy animals might appear.

Investigation of the effects of cricket ingestion on plasma uric acid concentration in inland bearded dragons (Pogona vitticeps)

OBJECTIVE

To determine whether plasma uric acid concentration in inland bearded dragons (Pogona vitticeps) was affected by recent ingestion of a meal of crickets.

ANIMALS

12 healthy adult inland bearded dragons.

PROCEDURES

Food was withheld for 48 hours prior to experiments. Animals (6/group) were randomly assigned to receive a meal of crickets (equivalent to 1% of the animal's body weight; 10 g/kg [4.5 g/lb]; treatment group) or have food withheld for an additional 48 hours (control group). Blood samples were collected for plasma uric acid measurement just before (time 0) and 4, 24, and 48 hours after feeding. Effects of feeding and time on the targeted measurement were assessed by repeated-measures ANOVA.

RESULTS

Mean plasma uric acid concentration for the treatment group was significantly increased from the time 0 value (2.5 ± 1.5 mg/dL) 24 hours following meal ingestion (6.5 ± 1.2 mg/dL), but not at the 4-hour time point, and returned to the time 0 value by the 48-hour time point. No significant changes in plasma uric acid concentration were detected for the control group.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested food should be withheld for ≥ 48 hours prior to blood collection if inland bearded dragons are used to establish reference intervals for plasma uric acid concentration or if feasible when obtaining samples from these animals for clinical evaluation. Veterinarians should consider the time from last meal consumption when interpreting plasma uric acid concentration for this species and potentially other terrestrial insectivorous and omnivorous lizards.