EN
The aim of investigations was to evaluate the invasion of mallophagan Werneckiella equi in primitive Polish horses during the alcove breeding period. In 6-20% of mares mallophagans were found during the entire period of investigations. In leading stallions the invasion intensity was insignificant and extensiveness amounted to 20%. Similarly, a low invasion of this parasite was initially ascertained in geldings and 1.5-year-old mares, subsequently the invasion increased. The height of mallophagan intensity occurred in April and its greatest extensiveness in May. In one-year-old mares from free breeding, parasites were discovered before their weaning from mothers, while of those that were caught in the forest and taken into stable in January, up to 50% were infected with mallophagans, in March and April respectively to a degree of 85% and 100%. Infection of one-year-old stallions from alcove breeding were considerably stronger than mares. In this group of horses mallophagans occurred as early as their stay with mothers. After their weaning, the intensity of the invasion increased, attaining its height in April. In 89% of stallions caught in the forest mallophagans were ascertained in January, after their moving into stables. Many factors influenced such a differential mallophagan infection of primitive Polish horses, among other things, age of animals, length of hair as well as sex and, additionally, in mares and stallions from free breeding, additional stress as a result of moving them into the stable.