Stopping My Ex Race Horse After A Gallop

Question
Hi there,
Hopefully with all your experience you will be able to give me some advice. My horse , Mister AzIz , is 15'2 full TB out of Mister Baileys and Aziz Presenting. He is 10 years old now and I have had him since December 2010. He was a sprinter and raced for 3 years finishing in 2006 with a bowed tendon so he had 18 months off. he was out to a few loan homes before I got him and now I am using him for hacking and local show jumping. He is a beautifull horse and a good wee jumper and hack the only thing is when I leet him out for a gallop he is very strong and just doesn't come back to me. He is very fit and loves galloping but  it can be quite dangerous as he switches into racehorse mode and is virtually unstoppable. I ride him in a French link snaffle however have tried a Dutch gag and a Pelham but neither made any difference . I also have a martingale on him. I have always worked with show jumpers and so am not used to the methods used for training race horses. Could you let me know of any tips that I can try when riding him to let him know when I want him to slow down ?  Thanks so much for any advice you can offer.

Answer
hi -- well if he is that strong with your different bits, then i would try some additive to his food to relax him a bit. you can also give him a dose of calm and cool 1 hr before you plan on riding him. you can ask your vet or horse feed store what products you can give your horse to get him relaxed when going riding . if you use a more sever bit , then you may aggravate your horse and he would fight the bit too much. hope this helps you. thanks ED HESS