An investigation of the potential for spread ofSarcocystisspp. and other parasites by feral cats

Abstract

The potential for spread by feral cats of parasites infecting sheep and cattle was investigated on 5 km² of New Zealand farmland. Faeces were collected to study diet and the prevalence of Sarcocystis and other parasites. The diet consisted primarily of rodents (50% by weight) with scavenged sheep (7%) relatively unimportant. Sarcocystis sporocysts were found in 4.8% of the faeces samples; given the predominance of rodents in the diet, it is more likely that these derived from species infecting rodents rather than farm animals. Toxoplasma gondii oocysts were not found. Eggs of the nematodes Toxocara cati and Capillaria spp. occurred in 67 and 52% of the samples, respectively. The home range and movements of feral cats were estimated using radiotelemetry. Female cats using barns and pasture had larger home ranges (1.88-2.79 km²) than those living in willows (0.37-1.09 km²). Adult males and a dispersing subadult male had larger home ranges (2.76-3.00 km²) than females. The density of resident feral cats was maintained at about 3.5/km² and seasonally supplemented by young and transient cats. The relative importance of feral and farm cats in the distribution of Sarcocystis and Toxoplasma gondii on farmland and the possibilities of controlling these vectors are discussed.