
I would make contact with the secretary of some of th4e Boxer breed clubs. Your boy may happen to be a good example of the breed, and someonje might be interested in new or interesting bloodlines.
At 9 years old it is rather late to be thinking of using him, and I would certainly have him checked re sperm quality!
If you make contact with the Kennel Club on 0870 606 6750 and get the Boxer club details and ask the advice of breed experts.
Your dog should be heart tested for heart murmurs and only used if the score is 0 or 1, and Hip Scoring is also advisable, and eyes may also need to be tested under a BVA opthalmologist!