**Abstract**

Zeolites have a wide range of use, from construction industries, aquaculture industries, agriculture, space research to human and veterinary medicine. This broad application of natural and synthetic zeolites is given by their main properties: adsorption, molecular sieving and cation exchange capacity. In this chapter the main use of zeolites in veterinary medicine is reviewed. The beneficial effects of zeolites in animal nutrition, on mycotoxins, as an adjuvant in anticancer treatment and in increasing passive immunity of newborn ruminants are reported. Furthermore, multiple advantageous immune effects of zeolites such as their antioxidant capacity or their non-specific superantigen-like immunoglobulin action are also reviewed. Finally, their main positive effect on passive immunity in newborn calves is discussed. Literature data reviewed confirms their beneficial role in newborn calves during colostral period.

**Keywords:** zeolites, feed additive, immunostimulation, ruminants
