Optimal dose and timing in phytohaemagglutinin skin-testing of deer

Abstract

AIM: To establish the optimal dose of the mitogen phytohaem- agglutinin (PHA) and the optimal time for measuring increased skin-fold thickness in red deer following intradermal injection, as an indicator of cell-mediated immune response.

METHODS: Three doses (10, 50 and 250 µg) of PHA were injected intradermally in the right side of the neck, and phosphate buffered saline (PBS) was injected at a fourth site as a control, in 20 captive Iberian red deer (Cervus elaphus hispanicus) hinds. Skin-fold thicknesses were measured at 0, 12, 24, 36, 48, 60, 72, 84 and 96 h following injection.

RESULTS: The highest dose of PHA tested (250 µg) resulted in a clear and long-lasting cellular response; increases in skin-fold thickness between 48 and 84 h post-injection varied minimally and response correlated positively with liveweight. No correlations with liveweight and no clear increases in skin-fold thickness occurred at the lower doses of PHA or the PBS.

CONCLUSIONS AND CLINICAL RELEVANCE: This technique could be applied with minimal training and without specialised equipment in deer, for immunological and ecological research.

KEY WORDS:

• Cellular immunity
• Cervus elaphus
• mammalian immune response
• wildlife bioindicators

Acknowledgements

Funding was provided by project AGL2005-07401 MEC-FED-ER and project RTA03-074 INIA. This is also a contribution to the agreement between FG-UCLM and Grupo Santander, and to the agreement between Y Fierro and the UCLM. We wish to thank the students and colleagues at IREC for their help with the laboratory and field work.