title: The effect of supplementation with vitamin A on serum and liver concentrations in Puerto Rican crested toads (Peltophryne lemur) and its lack of impact on brown skin disease.
abstract: "Brown skin disease" (BSD) is a clinical syndrome of dysecdysis, chronic weight loss and death, previously reported in Puerto Rican crested toads (Peltophryne lemur). Although vitamin A deficiency has been suggested, its cause remains unknown and multiple treatments have failed to prevent or reverse the condition. This study compared the efficacy of vitamin A supplementation, administered in different forms and by different routes, in 48 captive born Puerto Rican crested toads fed from metamorphosis on gut-loaded, dusted, commercially raised crickets. Forty-five toads started to show clinical signs of BSD at 9 months of age; all toads were treated orally with an oil-based vitamin A formulation twice weekly for 2 months but continued to deteriorate. Two treatment groups were then compared: Animals in one group (n=19) received 2 IU injectable vitamin A (Aquasol-A) per gram bodyweight subcutaneously twice weekly for 3 months with no change in diet. Toads in the other group (n=22) received a single oral dose of vitamins A, D3 , and E, and were fed on earthworms and crickets gut-loaded with produce and a finely-ground alfalfa-based pellet, dusted with the same vitamin/mineral supplement. All affected animals developed severe BSD equally and died during, or were euthanized at the end of, the treatment regimen, with no clinical improvement. Animals supplemented with Aquasol-A had significantly higher liver vitamin A concentrations compared with the other treatment group, whereas serum retinol concentrations showed no significant difference. Vitamin A supplementation does not appear a successful treatment once BSD symptoms have developed.
authors.affiliation: Toronto Zoo, Scarborough, Ontario, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Dutton
authors.forename: Andrew
authors.initials: A
authors.lastname: Lentini
authors.forename: Charlene
authors.initials: C
authors.lastname: Berkvens
authors.forename: Graham
authors.initials: G
authors.lastname: Crawshaw
mesh_terms: D000818:Animals; D000836:Animals, Zoo; D002025:Bufonidae / Q000097:blood / Q000378:metabolism*; D019587:Dietary Supplements; D008099:Liver / Q000378:metabolism; D012871:Skin Diseases / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome; D014801:Vitamin A / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
chemical_list: D014801:Vitamin A
keywords: amphibian; brown skin disease; vitamin A