Goat milk is commonly drunk in many countries and it's by-products, such as goat cheese remain popular.
The allergenic proteins in goat milk are generally split into albumins (commonly called whey) and casein. In human milk the split is usually 60% whey to 40% casein. In goat milk the split is 20% whey to 80% casein. This is a similar composition to cow's milk. This massive difference in composition is thought to be the cause of what causes IgE allergic reaction to mammalian milk, with most people being allergic to casein proteins in the milk.
Some breeds of goat make milk lacking α-s1-casein, which is the main casein in cow milk, this is less allergenic than goat milk with α-s2-casein, which is more typical for many goat breeds.
Most goat milk products are not suitable for those suffering from cow's milk protein allergy.
Goat milk is not currently associated with any allergic syndromes.
Cow, buffalo and sheep milk could all be cross reactive with goat milk due to similar composition.