Prevalence of Salmonella spp. in translocated wild reptiles and effect of duration of quarantine on their body condition

ABSTRACT

Aims

To assess the prevalence of carriage of Salmonella spp. in wild reptiles translocated from multiple locations to a single island, and determine changes in their body condition (BC) during quarantine.

Methods

Between 2007 and 2009, six endemic reptile species (Oligosoma aeneum, O. moco, O. ornatum, O. smithi, Dactylocnemis pacificus, and Woodworthia maculata) were caught from several locations in the northern North Island of New Zealand. Reptiles were held in quarantine for 14–41 days while being tested for carriage of Salmonella spp. Morphometric data were collected, and scaled body mass index for each species was calculated to determine changes in BC during the quarantine.

Results

Of 221 individuals tested 12 (5%) were positive for Salmonella spp. All 12 were shore skinks (O. smithi; n = 30), with a test prevalence of 0.4 (95% CI = 0.25–0.58). Eleven were carrying Salmonella enterica Warragul and one S. enterica Mississipi. There was no difference in BC at the start of quarantine of shore skinks between those that tested negative and those that tested positive for Salmonella spp. (p = 0.184). Reptiles that were quarantined for 15–20 days (three species) lost 3–5% of BC (mean proportional change 0.03–0.05), while those quarantined for >30 days increased BC by 3–13% (mean proportional change 0.03–0.13). All animals except the one individual positive for S. Mississippi were translocated to the recipient island, while the latter was returned to the source site.

Conclusions and clinical relevance

The prevalence of Salmonella spp. carriage in the translocated reptiles was low overall and consistent with other records of Salmonella spp. in wild New Zealand reptiles. However, the prevalence of 0.4 in shore skinks is the highest recorded in this species. In addition to time required for health-screening, we recommend that duration of quarantine should include time to allow animals to recover from captive stress and to provide an opportunity to increase their BC before release.

KEYWORDS:

• Conservation translocation
• health screen
• disease screen
• island restoration
• lizards
• New Zealand

Acknowledgements

We thank Friends Of Matakohe-Limestone Island, especially P. Mitchell, G. Brackenbury, L. Mead, and P. Anderson; Massey University (B. Gartrell, M. Barry, D. van Winkel, M. Delaney, M. Van Rensburg, C. Wong, J. Peace, D. Brunton), R. Parrish, and Department of Conservation. We also thank Northland Regional Council – Harbour Restoration Fund, and Golden Bay Cement for the funding provided.