Like people, dogs are individual in the way they age.

One of the first signs is a slower pace: in getting up, getting started from a lying position, climbing stairs. While some of these changes are natural, never assume that a change in behavior or habits is simply due to old age; it may be due to a treatable condition.

Diseases such as arthritis, diabetes, Cushing's disease, cancer, kidney, heart, and liver diseases occur in older dogs that are not usually seen in young dogs. Take your dog to a veterinarian for blood tests - these will screen many of these diseases, which may not have been detected during an annual visit.

Maintain the health of your older dog by

• keeping his weight down (through good nutrition and regular exercise),
• keeping his teeth clean (next to obesity, periodontal disease is the one most commonly seen in the vet's office)
• getting him to the vet for regular check-ups
• watching for symptoms that might indicate a health problem and get prompt appropriate veterinary attention.

Other factors that affect your dog's aging process are the following:

• Nutrition -- good nutrition will delay the aging process.
• Illnesses -- a serious illness or disease can shorten a dog's life.
• Genetic background -- some breeds are known to have specific health problems. Large breeds, for example, are prone to develop arthritis in back and hips as they age.
• Environmental factors -- keeping your dog and his environment clean and free of parasites will increase the chances of long life.

At the appropriate time, begin a geriatric screening for your dog, which will include: (1) a thorough, hands-on physical exam; (2) blood tests; (3) possibly an electrocardiogram; (4) specialized tests depending on your dog's health history.

General care of your aging dog will consist of periodic geriatric screenigs, in-between visits to the vet, and staying alert to behavioral changes and other signs of aging. Here are some things to watch for and action to take:

• Sudden loss of weight -- you must take your dog to the vet as soon as possible.
• Serious loss of appetite -- your dog is eating almost nothing. See your vet right away.
• Increase in appetite without increase in weight -- may mean diabetes. Get to the vet as soon as possible.
• Diarrhea or vomiting -- if it lasts more than a day, take your dog to the vet right away.
• Increased thirst, without a change in activity level, and increased urination -- these are other signs of diabetes, and you should have your dog tested as soon as possible.
• Tiring more quickly may be a sign of disease affecting the heart or lungs. Be alert to your dog's becoming excessively out of breath after minimal exercise. Have your vet check for cardio-pulmonary problems as soon as possible, if you notice such symptoms. If the vet determines all is normal, you can continue an exercise program, but modify it in order not to overtax your dog.
• Coughing and excessive panting may indicate heart disease. If these symptoms persist even after you've modified your dog's exercise program, visit the vet.
• Difficulty in getting up from a lying position, or other problems with moving may indicate arthritis. Your vet will be able to advise you on ways you can relieve your dog's discomfort and lack of mobility.
• Problems with vision and hearing are natural with aging. Try not to make changes in your home so as not to confuse your dog. Try clapping instead of calling your dog's name when he doesn't seem able to hear you.
• Graying hair and drying skin will require that you pay more attention to grooming and that you perhaps introduce some massage to help the condition of the skin and coat.

Among the behavioral changes that you may see in your older dog include:

• Separation anxiety - leaving your older dog alone may cause him to become destructive, bark or whine, or lose control of elimination.
• Sensitivity to noise - thunderstorms that never bothered him before may now make your older dog tremble.
• Increased aggression - may be due to painful joints, a drug reaction, or intolerance for new people and new circumstances; your older dog likes things to remain the same
• Confusion, lack of attentiveness, disorientation, roaming in circles, barking at nothing, being withdrawn, elimination accidents.

If your dog is acting abnormally in any of these ways, consult your vet right away.

In addition, give him plenty of attention and affection, and to the best of his ? and your- abilities, keep up the activities that he loved when you brought him home as a puppy.