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Variation in fecal egg counts in horses managed for conservation purposes: individual egg shedding consistency, age effects and seasonal variation

Published online by Cambridge University Press:  16 August 2012

E. L. D. WOOD ,
J. B. MATTHEWS ,
S. STEPHENSON ,
M. SLOTE  and
D. H. NUSSEY
E. L. D. WOOD
Affiliation:
Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh, UK
J. B. MATTHEWS*
Affiliation:
Disease Control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, UK
S. STEPHENSON
Affiliation:
Broads Authority, Dragonfly House, 2 Gilders Way, Norwich NR3 1UB, UK
M. SLOTE
Affiliation:
Norfolk Wildlife Trust, Bewick House, 22 Thorpe Road, Norwich NR1 1RY, UK
D. H. NUSSEY
Affiliation:
Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh, UK Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh, UK
*
*Corresponding author: Disease Control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, UK. Tel: +44 131 445 5111. Fax: +44 131 445 6111. E-mail: [email protected]
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Summary

Cyathostomins are the most prevalent equine intestinal parasites and resistance has been reported in these nematodes against all 3 licensed anthelmintic classes. Strategies need to be developed that are less dependent upon drugs and more reliant on management-based control. To develop these we need to understand natural transmission patterns better. Here, we analysed longitudinal fecal egg count (FEC) data from 5 pony populations used for conservation purposes. We tested how egg excretion varied amongst populations and individuals, and how this was affected by age and climate. There was evidence for consistency in FECs over time at the individual level; this was generally weak and accounted for <10% of the total variance. Animals <5 years old had higher FECs and there was profound seasonal variation in FECs, with highest levels recorded in spring/summer. Effects of monthly temperature and rainfall explained most, but not all, of the observed seasonal variation and associations between climate measures and FECs were stronger in younger versus adult animals. One population was occasionally treated with anthelmintics and analysis of this population suggested that treatment substantially altered the seasonal dynamics. This paper highlights the variability in strongyle egg excretion amongst individuals and the factors involved in this variation.

Keywords

horsesnematodescyathostominsfaecal egg countsconsistencyageclimate
Type
Research Article
Information
Parasitology , Volume 140 , Issue 1 , January 2013 , pp. 115 - 128
Copyright
Copyright © Cambridge University Press 2012

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