[CorkyMax]

If your senior dog is acting differently (and a dog is considered a senior sometimes as early as 7 yrs--depending on the breed!) you should check it out at the vet's. Many diseases, conditions can enter as your dog ages and it can act sick, aggressive--any change in it's normal behavior---AND it may not be JUST OLD AGE showing---It may be something compounded because of aging---As the dog ages, it is more prone to this happening. This link is a very good read:Caring for an Elderly Dog - Age is Often Mistaken as a Symptom of a Treatable Illness - Whole Dog Journal Article