Colostrum side effects are virtually non-existent and we have not experienced any that can be attributed to colostrum in our work with animals. This is because, in our view, colostrum is a whole food substance created by nature for very young mammals. If it had serious side effects new born animals would be in serious trouble! Colostrum is a food and is safe for dogs and cats of all ages. It can be consumed in large quantities without contraindications. Scientific research conducted in the last decade (in major medical research centers and universities throughout the world) has shown that the molecular combinations of the immune and growth factors in cow's colostrum are virtually identical to human. Research has also shown colostrum from a bovine (cow) is not species specific, and is up to 100-1000 times more potent than human colostrum. This means that every mammal on earth can benefit from bovine colostrum in a safe and natural manner, including our pets.