Abstract: A veterinary pharmaceutical composition for treating diseases of the gastrointestinal tract and intoxications of diverse etiology in animals comprises, as the active component, hydrolyzed lignin and a prebiotic from the following group: lactulose, fructooligo-saccharides, galacto-saccharides and inulin, and is in a form suitable for use in the composition of a mixture with combined feed, with a lignin content of from 30 to 95% by mass, in the form of powder of granules. The method for the prophylaxis and treatment of intoxication of diverse etiology, including mycotoxicoses, in animals, including birds, envisages that the animal will receive the above-mentioned veterinary pharmaceutical composition mixed with feed in a dosage of from 2 to 4.5 kg of the preparation per ton of combined feed, proportional to the content of mycotoxins in the combined feed.