RESUMO
Sustainable wildlife populations depend on healthy individuals, and the approach to determine wellness of individuals is multifaceted. Blood gas analysis serves as a useful adjunctive diagnostic test for health assessment, but it is uncommonly applied to terrestrial reptiles. This study established reference intervals for venous blood gas panels in free-living eastern box turtles (Terrapene carolina carolina, N = 102) from Illinois and Tennessee, and modeled the effects of environmental and physiologic parameters on each blood gas analyte. Blood gas panels included pH, partial pressure of oxygen (pO2), partial pressure of carbon dioxide (pCO2), total carbon dioxide (TCO2), bicarbonate (HCO3-), base excess (BE) and lactate. Candidate sets of general linear models were constructed for each blood gas analyte and ranked using an information-theoretic approach (AIC). Season, packed cell volume (PCV) and activity level were the most important predictors for all blood gas analytes (P < 0.05). Elevations in PCV were associated with increases in pCO2 and lactate, and decreases in pH, pO2, HCO3-, TCO2 and BE. Turtles with quiet activity levels had lower pH and pO2 and higher pCO2 than bright individuals. pH, HCO3-, TCO2 and BE were lowest in the summer, while pCO2 and lactate were highest. Overall, blood pH was most acidic in quiet turtles with elevated PCVs during summer. Trends in the respiratory and metabolic components of the blood gas panel tended to be synergistic rather than antagonistic, demonstrating that either (1) mixed acid-base disturbances are common or (2) chelonian blood pH can reach extreme values prior to activation of compensatory mechanisms. This study shows that box turtle blood gas analytes depend on several physiologic and environmental parameters and the results serve as a baseline for future evaluation.
RESUMO
Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (p<0.0001) between the UVB supplementation group (101.49±21.81 nmol/L) and the control group (36.33±24.42 nmol/L). An increased corneal thickness in both eyes was also found in the UVB supplementation compared to the control group (right eye [OD]: p<0.0001; left eye [OS]: p<0.0001). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing guinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended.
