EN
Mallophagans invasion constitutes a serious problem in horses during the alcove breeding period. The aim of investigations was to assess the course, extensiveness and intensity of W. equi invasion in mares of primitive Polish horses according to breeding manner and age. Studies were carried out from October 2006 to May 2007 on 17 mares. Eleven mares from this group were kept in a stable and during the day stayed in the paddock. The remaining horses spent all day and night constantly in the paddock and only during bad weather they could hide under a wooden umbrella roof. In 11.1-year-old stable-bred mares mallophagans appeared in January, in older mares (12.3-year-olds) from the group staying in the paddock they were observed in March and in the younger ones (9-year-olds) in April. The invasion of W. equi in all mares lasted until May. The extensiveness of mallophagan invasion in mares from the stable breeding was the greatest in January, in the older ones from the paddock in April and in the younger in May. The intensity of W. equi invasion was respectively: 1-9, 1.5-11 and 1-3.5 mallophagan/100 mg of coat. The peak intensity of mallophagan invasion in the older mares staying permanently in the paddock occurred in March, whereas in the mares from the stable breeding and younger ones staying in the open in April.