How much money can you make if you got a doctoral degree in animal medicne?

It's not a doctorate, and there's no such thing as "animal medicine." You're talking about a degree in Veterinary Medicine, D.VM. Ask a vet if you want to know--there are subspecialties, and some are more in demand in some parts of the country that others. There won't be much of a call for treating boutique pets in Spearfish, SD, and how many specialists in livestock are getting rich in Manhattan?