Abstract

Leaf-tailed geckos of the genus Uroplatus are found only on the islands of Madagascar. There are 10 recognized species of Uroplatus: U. fimbriatus, U. sikorae, U. lineatus, U. ebenaui, U. alluaudi, U. guentheri, U. phantasticus, U. malaheta, U. malama, and U. henkeli. In the wild, U. fimbriatus, U. sikorae, and U. phantasticus are relatively abundant while the other species have localized distributions and are rare.³ According to the International Species Information System (ISIS) Reptile Abstract (December 1995), the captive North American population of Uroplatus consisted of 245 individuals representing six of the 10 species, with U. henkeli, U. fimbriatus, and U. sikorae the predominant captive species.¹ Uroplatus are nocturnal active feeders (versus ambush feeders). They rest in a vertical position with head facing downward and tail flattened. Stress responses include color changes, high-pitched vocalization, and dropping of the tail. Males can be distinguished from females by thick hemipenal bulges.²

Husbandry surveys and requests for medical records and necropsy reports were sent to 28 public institutions in North America that currently maintain or that have maintained Uroplatus sp. in the past. A 52% response rate was achieved and a total of 85 necropsy reports were reviewed. Health problems identified by keepers/curators included dehydration, reluctance to feed, anorexia, injuries to the rostrum due to aggressive feeding behavior, and dysecdysis with retained skin on digits. Keepers noted a high mortality rate in recently imported species and in hatchlings. Common medical problems identified by veterinarians included anorexia of unknown etiology, weakness, ocular disease, general unthriftiness, paresis, problems related to oviposition secondary to calcium and phosphorous imbalances, Salmonella sp. infections, and early neonatal death. The majority (80%) of respondents felt that medical problems were related to husbandry and nutrition. Diagnostic procedures included cloacal cultures, radiology, fecal examinations, and blood work.

Of the 32 necropsy reports which contained a final diagnosis, 19 (59%) of these diagnoses were infectious in nature and included septicemia, hepatitis, pneumonia, colitis, enteritis, inflammation of the hemipene, egg yolk coelomitis, cloacitis, oviductitis, nephritis, salpingitis, and ophthalmitis (Tables 1, 2, and 3). A majority (49%) of infections involved the gastrointestinal and/or reproductive system. Noninfectious diseases included renal and articular gout, nutritional osteodystrophy, cystic ovaries, hepatic fibrosis, impaction, and trauma. Mortality in hatchlings was attributed to premature utilization of yolk sac prior to pipping possibly related to incubation humidity and temperature; congenital defects including contracted limbs, scoliosis, and schistothorax; impaction from vermiculite ingestion; and ocular infections. Gastrointestinal parasites were identified as pathological agents in several cases and protozoal flagellates and unidentified amoeba were implicated. Although Coccidia was a frequent finding on fecal exams, no pathology was attributed to their presence. Little is known about the distribution, natural history, and diseases of Uroplatus sp. in the wild. Captive husbandry and medical management of these animals could be enhanced by applied research in this area.

Table 1. Most common findings in 41 necropsy reports from adult leaf-tailed geckos

^aPercentages do not equal 100% because more than one lesion could be reported per animal.

Table 2. Histopathological diagnosis in 32 adult leaf-tailed geckos

Table 3. Specific problems found in leaf-tailed geckos at necropsy

Acknowledgments

Recognition and gratitude goes to the veterinarians, keepers, curators, and pathologists who contributed this information. They represent the following institutions to date: Birmingham Zoo, Center for Endangered Reptiles, Central Florida Zoological Park, Chaffee Zoological Gardens of Fresno, Cincinnati Zoo and Botanical Garden, Dallas Zoo, Detroit Zoological Institute, Fort Worth Zoological Park, Louisville Zoological Garden, Milwaukee County Zoological Garden, Riverbanks Zoological Park and Botanical Garden, St. Augustine Alligator Farm, Virginia Zoological Park, Wildlife Conservation Society, and the Zoological Society of San Diego.

Literature Cited

1.  Foley SC. Malagasy leaf-tailed geckos: North American Regional Studbook. Columbia, SC: Riverbanks Zoological Park. 1996.

2.  Nussbaum RA, Raxworthy CJ. A new species of Uroplatus dumeril (Reptilia: Squamata: Gekkonidae) from Southern Madagascar. Herpetologica. 1994:50:319–325.

3.  Raxworthy CJ, Chapman P, Ganzhorn JU, Bloxam QMC, Barlow SC, Tonge SJ. Vertebrate conservation in Ankarana Special Reserve, Northern Madagascar. Biol Conserv. 1990;54:83–110.