Selenium and Dogs: A Systematic Review

SIMPLE SUMMARY: Selenium is a microelement which intake is essential for correct function of the metabolism. In a dog’s body, it is important, for example, for its antioxidant function, its role in thyroid metabolism, synthesis of DNA, or reproduction. It seems that it also plays an important role in prevention and treatment of cancer. While nutritional recommendations for its content in commercial dog food exist, they do not differ between types of food, such as kibble versus canned food. Home-made diets have lower content of selenium than commercial food, but selenium may have greater bioavailability from raw products than processed ones. Moreover, reference values for its levels in dog’s serum, plasma, full blood, and tissues are not very well defined. ABSTRACT: The intent of this review is to summarize the knowledge about selenium and its function in a dog’s body. For this purpose, systematic literature search was conducted. For mammals, including dogs, a balanced diet and sufficient intake of selenium are important for correct function of metabolism. As for selenium poisoning, there are no naturally occurring cases known. Nowadays, we do not encounter clinical signs of its deficiency either, but it can be subclinical. For now, the most reliable method of assessing selenium status of a dog is measuring serum or plasma levels. Levels in full blood can be measured too, but there are no reference values. The use of glutathione peroxidase as an indirect assay is questionable in canines. Commercial dog food manufactures follow recommendations for minimal and maximal selenium levels and so dogs fed commercial diets should have balanced intake of selenium. For dogs fed home-made diets, complex data are missing. However, subclinical deficiency seems to affect, for example, male fertility or recovery from parasitical diseases. Very interesting is the role of selenium in prevention and treatment of cancer.