In vivo studies on mice have shown that IgY can be an alternative to horse serum antivenoms to rattlesnake and scorpion toxin. Cryptosporidium is a

zoonotic pathogen that infects the respiratory or gastrointestinal tracts of a large number of hosts including fish, birds, reptiles, and mammals. Cryptosporidium infections are usually associated with immunosuppressed hosts but it may also occur in individuals with a normal immune system. The use of yolk preparations with high anti-Cryptosporidium activities caused a significant parasite reduction in a neonatal mouse model. Treatment with bovine anti-Cryptosporidium colostrum immunoglobulin has also been shown to induce a 100-fold reduction of oocyte excretion in healthy human volunteers. A maternal transmission of parasite specific IgY against the protozoan Eimeria maxima, that cause coccidiosis in poultry, are highly protective, mediating up to 97 % reduction in oocyst excretion in challenged hatchlings. Bovine anti-Candida albicans antibodies have been used as a prophylaxis in bone marrow transplanted patients. The results show that a there was a treatment related reduction in candida colonization in a majority of the patients.