DO PATTERNS OF HELMINTH PARASITISM DIFFER BETWEEN GROUPS OF WILD-LIVING CATS IN SCOTLAND

Differences in the prevalence and abundance of helminth parasites amon gst host populations may result from variations in resistance to infec tion, differences in habitat preferences, diet or social behaviour. Th e use of helminth parasites as 'ecological markers' for determining di fferences between morphological groups of wild-living cats in Scotland was investigated, in light of the debate over the definition of a wil dcat. The prevalence and abundance of the tapeworm Taenia taeniaeformi s did not differ significantly between cats designated as 'wild' and ' feral' types. The prevalence of both helminths was high (94% and 69%, respectively) and there was significant variation in worm abundance re lated to season and geographical area. Also, prevalence of infection w ith Toxocara cati was significantly higher in female cats. Cats which harboured large numbers of one worm species were also likely to harbou r large numbers of the other. However, a possible relationship with ca t condition was only found for T. taeniaeformis for which there was a significant negative correlation between an index of cat condition and worm abundance amongst 'wild type' cats, but not amongst 'feral type' cats. Variations in worm burdens could not be attributed to differenc es in the diet of the cats as there was no significant relationship be tween the presence of any individual prey type and either the presence or abundance of T. cati or T. taeniaeformis. There was a significant negative correlation between density and biomass of individual worms i n infections of T. taeniaeformis, suggestive of a density-dependent co nstraint on tapeworm growth.