Change in nutritional needs and weight changes
As dogs age, their metabolism changes and their need for calories decreases. Because their activity usually decreases as well, their energy needs are decreased by 10-20%. If we feed older dogs the same amount we fed them when they were young, they will gain weight
Skin and hair coat changes
As with people, older dogs may start to show gray hair; this most commonly occurs on the muzzle and around the eyes.
Decreased mobility and arthritis
Arthritis is a common occurrence in older dogs, especially large breed dogs. As in people, arthritis in dogs may only cause a slight stiffness, or it can become debilitating. Dogs may have difficulty going up and down stairs or jumping.
Chondroitin and glucosamine can be beneficial to support healthy joints. Some anti-inflammatory pain relievers such as aspirin and Rimadyl are often recommended for dogs with arthritis. (Do NOT give your cat any type of pain reliever unless prescribed by your veterinarian.)
Dental disease is the most common change we see in older dogs. Studies show that even by age three, 80 percent of dogs exhibit signs of gum disease
Decreased gastrointestinal motility (constipation)
As dogs age, the movement of food through their digestive tracts slows. Inactivity can also contribute to constipation.
Urinary incontinence and loss of house training
Urinary incontinence is involuntary or uncontrollable leaking of urine from the bladder. In older dogs, especially spayed females, small quantities of urine may leak while the dog is resting or sleeping. Treatment for incontinence is usually not difficult. Phenylpropanolamine (PPA) and estrogens, such as diethylstilbestrol, are commonly used.
Some dogs will experience hearing loss as they age. Slight hearing loss is hard to evaluate in dogs. Often hearing loss is severe before the owner becomes aware of the problem. The first sign noticed may look like aggression. In reality, it may be the dog was unaware of a person’s approach, became startled when touched, and instinctively reacted. Owners may also report the dog is no longer obeying commands (the dog no longer hears them).
The hearing loss generally can not be reversed, but some changes in interaction with the dog can help reduce the effects. One of the reasons to teach dogs hand signals for various commands while they are young, is that these hand signals are very useful if the dog develops hearing loss
Changes in the eye and vision loss
Many dogs develop a condition of the eye called nuclear sclerosis. In this condition, the lens of the eye appears cloudy, however, the dog can usually see quite well. Many owners are concerned their dog has cataracts (which do affect vision) when the dog really has nuclear sclerosis. Cataracts are common in older dogs of certain breeds, though, as is glaucoma.