How can I stop my 10yr old dog from smelling?

Give him a bath?

What kind of smell? Body Oder? Breath? Gas?

How can I stop my 10yr old dog from smelling

Body odour

how can i stop my 10yr old dog from smelling of body odour

Give him a bath. Take him to the groomers.

Shampoos :: earthbath® - totally natural pet care (http://www.earthbath.com/shampoo.php) Try a shampoo from EarthBath... that line of shampoos smells pretty good.

If you take him to the groomers,they have the professional dog shampoo lines there and would help take the body oder away... To maintain a good smelling dog, you can always spray him with a cologne once a week.

Try introducing Omega oils into his diet, get a shampoo specifically designed for dogs with allergies, I like allergroom.
A healthy dog shouldn't smell, so has there been any changes in diet or home life?
Could be that your dog is smelling from the inside out! He could be suffering from dental disease, an ear infection, allergies, or even kidney disease.
If the odour is persistent, you may want to consider taking him for a good once over by your vet.
One of the best ways to get rid of body odor is to switch your pet to a natural diet.
You can try adding barley grass, wheat grass, or chlorophyll as they can remove toxins from the body that can lead to bad smells.
Omegaderm Oil, available from vets is a great and in expensive omega or fatty oil you can try adding. One of our shelter dogs is on Gerizyme. Also fairly in expensive.
Also try to groom daily, as this helps remove some smells that are trapped under their under coat.