Med. Weter. 1 Artykuł przeglądowy Review DOI: dx.doi.org/10.21521/mw.6457 Dietary supplements As awareness of the role of prevention in pets’ health has grown among pet owners in recent decades, dietary supplements have increased in popularity (25). Such products are taken orally and contain one or more dietary ingredients intended to supplement the diet (37) and prevent nutritional defciency (44), such as vitamins, minerals, herbs, other nutraceutical plants, amino acids, and substances such as enzymes, organ tissue, and metabolites. Nutritional supplements not only help prevent the development of diseases, but are also a form of comple- mentary or alternative medicine (CAM) which can be used instead of, or alongside, conventional medicinal products to reduce adverse drug effects (23). Several supplements, such as curcumin, S-adenylo-methionine Dietary supplements containing silymarin as a supportive factor in the treatment of canine hepatopathies MACIEJ GOGULSKI* , ** , ***, MARIE ARDOIS****, JULIA GRABSKA****, KACPER LIBERA*, MAŁGORZATA SZUMACHER-STRABEL****, ADAM CIEŚLAK****, VIOLA STROMPFOVÁ*** *Department of Preclinical Sciences and Infectious Diseases, Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Wołyńska 35, 60-637 Poznań, Poland **University Centre for Veterinary Medicine, Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Szydłowska 43, 60-656 Poznań, Poland ***Centre of Biosciences, Slovak Academy of Sciences, Institute of Animal Physiology, Šoltésovej 4-6, 040-01 Košice, Slovak Republic ****Department of Animal Nutrition, Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Wołyńska 33, 60-637 Poznań, Poland Received 27.04.2020 Accepted 02.06.2020 Gogulski M., Ardois M., Grabska J., Libera K., Cieślak A., Szumacher-Strabel M., Stromprová V. Dietary supplements containing silymarin as a supportive factor in the treatment of canine hepatopathies Summary We review canine dietary supplements, in particular silymarin and its hepatoprotective properties. Dietary supplements should be considered complements to conventional drug treatments, helping to prevent health issues, such as nutritional defciencies and organ dysfunctions. The market for veterinary supplements is growing rapidly. Pet owners are increasingly eager to provide their animals with the best care available. The rapidly growing market of supplements is an opportunity for both the industry and veterinarians, who can introduce new treatment protocols supported by dedicated dietary supplements. The liver is one organ that can be nutritionally supported in case of dysfunction. In dogs, hepatopathies may be primary or may be secondary to an underlying problem. Toxins, drugs, and neoplasia are reported among the causes of liver dysfunctions. There are several substances with proven liver-benefcial properties. One of these is silybin, a hepatoprotector extracted from Silybum marianum. Dietary supplementation with silybin seems a reasonable tool to support a core treatment for liver disease. Laboratory tests have additionally shown that silybin supplementation helps reduce liver damage. The literature indicates that silybin acts not only as an antioxidant, but also as an antifbrotic agent and a stimulator of cell regeneration. Due to its multidirectional action, it can effectively reduce liver damage, or help prevent it. Independent of the reason for its administration (prevention or therapy), it has been reported effective in laboratory animals, dogs, and humans. This was confrmed by an observational study performed at the University Center for Veterinary Medicine at Poznań University of Life Sciences. A total of 15 dogs with diagnosed liver conditions were supplemented with silybin for 30 days. Signifcant improvements were reported in the liver blood markers after the supplementation period. All things considered, silybin dietary supplementation is a noteworthy strategy in prevention and treatment of liver diseases in dogs. Keywords: dietary supplements, canine hepatopathies, silymarin, silybin