Objective—To determine whether there are increased concentrations of 25-hydroxyvitaminn D3 in red-eared slider turtles (Trachemys scripta elegans) after exposure to UV radiation.
Animals—12 yearling turtles recently removed from aestivation.
Procedures—Turtles were randomly allocated to 2 groups (6 turtles/group). An initial blood sample was collected from all turtles for measurement of 25-hydroxyvitamin D3 concentrations. Turtles of 1 group were then provided no supplemental lighting, whereas turtles of the other group were exposed to full-spectrum coil bulbs at a distance of 22.86 cm. The UV-A and UV-B radiation generated by the supplemental lighting was measured by use of a radiometer-photometer at weekly intervals. Measurements were collected 2.54 and 22.86 cm from the bulb surface. The study was continued for a 4-week period. At the end of the study, a second blood sample was collected from all turtles for measurement of 25-hydroxyvitamin D3.
Results—Mean ± SD 25-hydroxyvitamin D3 concentrations differed significantly between turtles provided supplemental UV radiation (71.7 ± 46.9 nmol/L) and those not provided UV radiation (31.4 ± 13.2 nmol/L).
Conclusions and Clinical Relevance—Appropriate husbandry recommendations for raising and maintaining red-eared slider turtles should include use of sunlight that is unobstructed by UV-B filtering material or provision of an artificial source of UV-B radiation.
Objective—To determine the effects of UVB radiation produced by artificial lights on serum 25-hydroxyvitamin D concentrations in domestic rabbits (Oryctolagus cuniculi).
Animals—9 juvenile domestic rabbits.
Procedures—After an acclimation period, rabbits were anesthetized with isoflurane, and an initial blood sample was collected for determination of serum 25-hydroxyvitamin D concentration. Rabbits were randomly assigned to receive 12-hour exposure to UVB radiation produced by 2 compact fluorescent lights daily (n = 5) or no UVB supplementation (4) commencing on day 1. The UVB radiation emitted into the cage was measured at 9 points approximately 34 cm from the surface of the UVB light sources (representing the position of the rabbits in the cage) after 10 hours of exposure on days 1, 8, and 14. On day 14, another blood sample was collected from anesthetized rabbits for determination of serum 25-hydroxyvitamin D concentration.
Results—The UVB radiation level was 8.3 to 58.1 μW/cm2 for the exposed rabbits and consistently < 0.001 μW/cm2 for the control rabbits. Mean ± SD serum 25-hydroxyvitamin D concentrations in the rabbits that were or were not provided supplemental UVB radiation for 14 days differed significantly (66.4 ± 14.3 nmol/L and 31.7 ± 9.9 nmol/L, respectively).
Conclusions and Clinical Relevance—Exposure to UVB radiation produced by artificial light significantly increased serum 25-hydroxyvitamin D concentration in juvenile rabbits. Because vitamin D is an essential hormone in vertebrates, these findings suggested that the provision of supplemental UVB radiation to captive rabbits may be important.
Objective—To determine whether corn snakes exposed to UVB radiation have increased plasma 25-hydroxyvitamin D3 concentrations, compared with control snakes.
Animals—12 corn snakes (Elaphe guttata).
Procedures—After an acclimation period in individual enclosures, a blood sample was collected from each snake for assessment of plasma 25-hydroxyvitamin D3 concentration. Six snakes were provided with no supplemental lighting, and 6 snakes were exposed to light from 2 full-spectrum coil bulbs. By use of a radiometer-photometer, the UVA and UVB radiation generated by the bulbs were measured in each light-treated enclosure at 3 positions at the basking surface and at 2.54 cm (1 inch) below each bulb surface; the arithmetic mean values for the 3 positions at the basking surface and each individual bulb surface were calculated immediately after the start of the study and at weekly intervals thereafter. At the end of the study (day 28), another blood sample was collected from each snake to determine plasma 25-hydroxyvitamin D3 concentration.
Results—Mean ± SD plasma concentration of 25-hydroxyvitamin D3 in snakes that were provided with supplemental lighting (196 ± 16.73 nmol/L) differed significantly from the value in control snakes (57.17 ± 15.28 nmol/L). Mean exposure to UVA or UVB did not alter during the 4-week study period, although the amount of UVA recorded near the bulb surfaces did change significantly.
Clinical Relevance—These findings have provided important insight into the appropriate UV radiation requirements for corn snakes. Further investigation will be needed before exact husbandry requirements can be determined.
Procedures—A blood sample (0.5 mL) was collected from the right jugular vein of each parrot and placed into a lithium heparin microtainer tube. Samples were centrifuged, and plasma was harvested and frozen at −30°C. Samples were thawed, and plasma osmolality was measured in duplicate with a freezing-point depression osmometer. The mean value was calculated for the 2 osmolality measurements.
Results—Plasma osmolality values were normally distributed, with a mean ± SD of 326.0 ± 6.878 mOsm/kg. The equations (2 × [Na+ + K+]) + (glucose/18), which resulted in bias of 2.3333 mOsm/kg and limits of agreement of −7.0940 to 11.7606 mOsm/kg, and (2 × [Na+ + K+]) + (uric acid concentration/16.8) + (glucose concentration/18), which resulted in bias of 5.8117 mOsm/kg and limits of agreement of −14.6640 to 3.0406 mOsm/kg, yielded calculated values that were in good agreement with the measured osmolality.
Conclusions and Clinical Relevance—IV administration of large amounts of hypotonic fluids can have catastrophic consequences. Osmolality of the plasma from parrots in this study was significantly higher than that of commercially available prepackaged fluids. Therefore, such fluids should be used with caution in Hispaniolan Amazon parrots as well as other psittacines. Additional studies are needed to determine whether the estimation of osmolality has the same clinical value in psittacines as it does in other animals.