Comparison of Oral and Topical Vitamin A Supplementation in African Foam-Nesting Frogs (Chiromantis xerampelina)
A captive population of African foam-nesting frogs (Chiromantis xerampelina) with a history of hypovitaminosis A had higher than expected incidence of sudden death, bacterial osteomyelitis, stunted growth, and lethargy. This study was undertaken to compare vitamin A oral supplementation to topical treatment with water-miscible vitamin A palmitate (AQUASOL A® Parenteral; Mayne Pharma Inc., Paramus, NJ, USA) in this population. Eighty-four frogs, weighing 2–7 grams, were divided into a control and three treatment groups (normalized weight distribution). The control group received standard daily nutrition of “dusted” crickets containing 342,000 IU vitA/kg. The treatment groups consisted of: (1) oral supplementation with a supplement designed for carnivores containing 822,510 IU vitA/kg, (2) topical vitamin A palmitate 50 IU every other day, and (3) topical vitamin A palmitate 50 IU once per week. After 30 days, all frogs were euthanatized and 12 frogs from each group were analyzed for whole-body vitamin A levels. The control and treatment groups 1, 2, and 3 had average whole-body vitamin A levels (IU/kg) of 1371.4 (SE 284.4), 908.7 (186.5), 6385.9 (675.9), and 3521.8 (575.1), respectively. These results suggest that oral supplementation using a product high in vitamin A is ineffective at raising whole-body vitamin A levels above those achieved with standard nutrition in this trial. This requires further investigation as the bioavailability of the oral supplement for amphibians is uncertain. Topical administration on an every other day and once per week dosing schedule achieved levels 4.5- and 2.5-fold higher than standard nutrition, respectively.