As the saying goes ... an ounce of prevention is worth a pound of cure. The American Veterinary Medical Association recommends regular wellness exams for your Boxer. From the AVMA website: "... if you can detect a problem in its early stages, it's more likely to be treated and resolved with less expense, less difficulty and better success."
When you see your Boxer's veterinarian, be sure to ask questions, whether those questions focus on specific issues or the general well-being of your dog. An informed owner is a better owner!
The articles on these pages are certainly not a substitute for talking with your veterinarian, but they will give you some information - a place to start.