Instead give him salad and fresh fruits as treats. Supply regular doses of Vitamin C and E to your pet. Consult your vet, you can get them in powdered form that can be easily mixed with the food. These vitamins help in building up the immune system. As they age, dogs tend to drink little water, which can lead to them getting dehydrated.
Dogs tend to lose their power of hearing, as they age.
It is thus a good idea to keep it on leash when going out or stick indoors. Ageing dogs tend to become cranky and thus they snap easily. You should understand that they are not as agile and tolerant as they used to be and that they can bite at slightest provoking. If there are children in house you have to make sure that they do not unnecessarily trouble the dog. Elderly dogs are very prone to cancer.