I wouldn't feel comfortable restricting food with a puppy, as they are still growing as they should naturally. And at 9 months your boy is still considered a puppy. I would ask your vet before I fed less.
With my males (my own and fosters) I've continued to feed the normal amounts and most have been puppies in the 6-10 months range. After they've healed completely and as they mature, I do try to increase their activities to avoid unnecessary weight gain, especially if I see one of them gaining weight. I weigh them all about once a month, so I keep good tabs on their weights.
I've had only one (Louis) that seemed to balloon and that wasn't just immediately after neutering but, gradually that first year after. We've been on a weight reduction program with him though, the last 6 months and he is doing wonderfully, lost a pound and has only about 1/2 pound to go! With Louis I've slightly decreased his food, so as not to make feel slighted, and increased his activity (walking). We've also made most snacks low-cal and healthy, veggies, fruits and no more sharing dh cookies!
__________________  ~Ruby, Reno, Razz, & Jack~ |