Bought and ate meat from a butcher who raises their own cattle but doesn't sell to stores. how can i trust their meat? i'm based in california should i worry about mad cow disease?

First, there have not been cases of mad cow in this country for years. Second, even if he is just selling to private individuals, and not to stores, he still has to be licensed and inspected. Your state inspector can let you know if his operation has ever had questionable ratings/inspections. Or just ask the butcher to see his inspection papers before you shop there. Cook meat thoroughly helps!

Agree with Dr. Maes. For the sake of your health, you should limit your intake of meats. Vegetarian diets are more healthful. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Wish you good health!