According to the indictment, this is not something he just sort of fell into.
Here it is. It's long, but it really lays what Vick and his co-defendents are alleged to have done. And from the sounds of it, some of the people allegedly involved have turned on him.
2. It was part of the conspiracy that the defendants and their co-conspirators would and did:
a. purchase and develop a parcel of property to serve as the main staging area for housing and training pit bulls involved in the animal fighting venture and for hosting dog fights;
b. establish a kennel name to represent the animal fighting venture in dog fighting competitions;
c. purchase pit bulls for use in dog fighting competitions;
d. train and breed pit bulls for participation in dog fighting competitions;
e. travel to other locations in interstate commerce to participate in dog fighting competitions;
f. sponsor and exhibit dogs in animal fighting competitions in interstate commerce involving dogs that have moved across state lines;
g. provide funding for the expenses associated with the ongoing animal fighting venture, including improvements on the property, dog food, medicine, and purse fees for dog fighting competitions and
h. develop the animal fighting venture's pool of pit bulls by testing the fighting prowess of dogs within the venture, providing veterinary treatment for injured dogs slated to stay with the kennel, and destroying or otherwise disposing of dogs not selected to stay with the ongoing animal fighting venture.