Doctor of Philosophy (PhD)


Veterinary Medical Sciences - Pathobiological Sciences

Document Type



First described in 1967, Isospora amphiboluri has become recognized as an important pathogen of bearded dragons. To date, no cross-sectional, pathogenesis, or treatment study has been performed to shed light on the epidemiology or treatment of I.amphiboluri. Two large breeding populations of bearded dragons were examined for the presence of I. amphiboluri oocysts using sucrose flotation and fecal direct saline smears. Parasites were more likely to be identified on fecal flotation (p= 0.03). A previously unidentified Eimeria species was examined and described as a new species for which we suggest the name Eimeria pogonae. To develop an understanding of the epidemiology of I. amphiboluri, characterization of the life cycle is needed. Fifteen I. amphiboluri negative dragons were used to determine the prepatent period, which ranged from 15-22 days. An additional 25 animals were infected with 20,000 sporulated oocysts to examine distribution in the gut. Animals were separated into five groups and euthanized at 4, 8, 12, 16 and 20 days post-infection and necropsy was performed. Infection began in the duodenum and move throughout the intestine. No extra-intestinal stages were found. Success with managing this parasite in captivity requires effective treatment. The first treatment study used three treatments, sulfadimethoxine, Pediococcus acidilactici, and oregano oil. Each group was treated for 21 days with 50mg/kg sulfadimethoxine, 10,000 CFU of P. acidilactici or 0.1 ml of Origanum vulgare essential oil. No significant difference was found in P. acidilactici, or oregano groups over time. There was a significant difference in sulfadimethoxine group over time (p=0.0001); however, the 21 day treatment was not sufficient in eliminating all of the parasites. The second treatment study evaluated ponazuril at three different doses. Each group was treated daily for 21 days with one of 4 treatments: isotonic saline, 15mg/kg ponazuril, 30mg/kg ponazuril and 40mg/kg ponazuril. All treatment groups showed a significant difference in shedding (p = 0.0001 each), suggesting that this drug could control the parasite in captive populations. I. amphiboluri is an important parasite of bearded dragons that has a moderate to high prevalence depending on husbandry methods. The combination of quarantine based on a 15-22 day prepatent period and treatment with ponazuril should be sufficient to control this parasite in captive populations.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

James Miller