Immune and parasitological response in horses infected with gastrointestinal nematodes in the humid tropic of Mexico

The objective of the study was to determine parasitological and immune response in horses naturally re-infected with gastrointestinal nematodes (GIN) after an- thelmintic treatment humid tropic Mexico. conducted Tenosique, Tabasco, A total 30 were sampled monthly for nine months. Fecal samples obtained number nematode eggs per gram (EPG) feces. Stool cultures performed obtain identify infective larvae (L3) genera. Blood also packed cell volume (PCV), plasma protein (TPP), differential leukocyte count (DLC). Serum enzyme-linked immunosorbent assays (ELISA) IgA levels against adult cyathostomins Strongylus antigen. analyses considered age gender horses, season (Cold, rainy dry). EPG TPP higher females (1224 ± 1269 7.6 0.6 gdL−1, respectively) than males (623 671 7.4 0.5 respectively), no differences observed animal (p > 0.05). increased season. main involved subfamily Cyathostominae (97.4%) a lesser degree species equinus, S. edentatus, vulgaris, Oxyuris equii. affected leukocytes, neutrophils, lymphocytes counts but not eosinophils. Variables such as gender, age, environmental conditions are important elements diagnosis GIN application treatments its control.