Lungworm Occurrence in Wild Boar Stocks Subject to Different Management Actions

Abstract

Lungworm ( Metastrongylus spp.) occurrence in wild boar ( Sus scrofa ferus ) was examined in two boar enclosures (fenced areas) and in the surrounding open area of middle Somogy county, SW-Hungary, in the 2002/03 hunting season. The studied areas presented the following characteristics: 1) S-enclosure (E1): 300 ha, 88% forest cover and 220 boars prior the hunting season; food containing ivermectin used for 7 days in late May. 2) T-enclosure (E2): 213 ha, 61 % forest and 170 boars; food containing albendazole was offered for one week in late May and one week in late June. 3) The open hunting area (OH): 6.000 ha, 67 % afforestation, estimated boar population around 250-300 individuals. During the hunting season (November - January), the harvested animals were investigated at the carcass collecting sites. Worms were collected from the lungs and were counted using a stereomicroscope in the laboratory. Bootstrap 2-sample t-test was applied for the statistical analysis. Lungworm occurrence of boars shot in E1 (n=98) showed 90.8 % prevalence with 104.2 mean and 79 median intensity. Boars shot in E2 (n=40) had 50.5 % prevalence with 76.05 mean and 23.5 median intensity. OH boars (n=17) had 88.2 % prevalence with 57.3 mean and 30 median intensity. There were no significant differences among the mean intensity values of the sample groups, however the mean abundance of the E1 and E2 boars differed strongly, even at the 0.2 % level. According to the age and sex groups, significant differences were proved between the mean intensity values of the young boars (51.5 worm/host, both sexes pooled) and the adult saws (108.0 worm/ host) in E1 only. On the basis of the above findings we think that one anthelmintic treatment (either with albendazole or ivermectin) during the summer - if necessary at all - is enough to avoid the outbreak of a serious lungworm disease.