[1] Kreavet, Hendrik Mertensstr 17, B-9150 Kruibeke, Belgium
[2] Swedish Univ Agr Sci, Dept Biomed Sci & Vet Publ Hlth, Sect Parasitol, Box 7036, S-75007 Uppsala, Sweden
[3] Queens Univ Belfast, Biol Sci, 19 Chlorine Gardens, Belfast BT9 5DL, Antrim, North Ireland
[4] Univ Ghent, Fac Vet Med, Lab Parasitol, Salisburylaan 133, B-9820 Merelbeke, Belgium