Abstract
The article presents the results of a study of clinical and pathological changes in the organs and tissues of horses that developed gastrofilosis spontaneously. Pathomorphological research materials were obtained in 2024-2025 from the SemeyVet LLP slaughterhouse in the Abai region, from horses slaughtered there. The study included 25 slaughtered horses aged three to five years. Of these, 8 (32%) had gastrophilosis. In all cases, anamnestic data were collected and analyzed. In each case, a complete veterinary and sanitary examination was conducted, and a report was prepared. In cases of severe infestation, hundreds of larvae were found in the stomach and duodenum, attached in clusters to the mucosal surface. At the sites of attachment of the parasite larvae to the gastric mucosa, redness and ulcerative lesions were found, devoid of epithelial covering. Granular dystrophy developed in the parenchymal organs, and catarrhal inflammation of varying severity developed in the digestive tract. The epithelium of the abdominal cavity was destroyed at the site of gastrophilum detection, and diffuse infiltration was detected in the proper and submucosal layers. In addition, signs of interstitial myositis were noted in the muscle layer of the stomach and intestines.