Diagnosis, treatment and outcomes for koala chlamydiosis at a rehabilitation facility (1995–2005)

JE Griffith* and DP Higgins


*Corresponding author.

Faculty of Veterinary Science, The University of Sydney, New South Wales, Australia;


Objective   To document the application of diagnostics and treatments at one rehabilitation facility over 10 years and their effects on recovery and post-release survival of 88 koalas treated for chlamydiosis, and to highlight associated wildlife care issues with potential significance to animal welfare and disease ecology.
Design   Using a retrospective analysis of medical records, we identified risk factors for successful release using a logistic regression model and descriptive statistics.
Procedure   We examined the clinical presentation, signalment, diagnostics, treatments, outcomes and whether released koalas were re-presented by the end of 2008 indicating post-release survival.
Results   Records of 88 koalas were included. Treatments and diagnostics were directed at the anatomical site displaying clinical signs. Younger age and use of ancillary treatments were associated with successful release. The type, route and duration of the treatments used were not those theorised to result in microbial cure. Despite this, approximately 50% of koalas were released and many survived in the wild for extended periods.
Conclusions   Wildlife rehabilitators’ records can guide research priorities and the development of care facilities and policies. This study identified the need for more accessible chlamydial diagnostic tests and veterinary support of carers, and the need for a more rigorous assessment of novel therapies. Current treatment regimens appear to be moderately successful in terms of clinical improvement, but it is unclear which aspects are responsible for the success or whether microbial cure is achieved. The long-term effect of released koalas on wild populations requires further study to assess its contribution to the conservation of koala populations.