One way the arrival of the Spanish changed Indians lives forever was the introduction of the horse. When you live a nomadic life style and had to physically carry everything you owned, your possessions were limited. Yet a horse and carry 200 pounds and pull another 300. Think how much your way of life improved being able to possess more things to help in your day to day life. On the down side, the horse also allowed diseases to spread faster and helped in pandemics that wiped out thousands of Indians. Without the horse some diseases would die out or be contained before they could spread long distances.
Historically Speaking 