Cognitive Dysfunction in Senior Dogs

After a lifetime of excited tail wagging, loyal companionship and memorable moments with your dog, you come home from work and your buddy is no longer at the front door to greet you.

Rover's sacked out on his doggy bed snoozing away, while you stand there wondering what has happened. Where did the display of liveliness and affection go that you've come to find irresistible?

Sure, he's getting a little gray around the muzzle, he walks a little slower and last week he wasn't interested in a game of catch. Your dog's changing behavior may be more than simply aging.   Pet owners may be unaware of a common condition called cognitive dysfunction syndrome (CDS), similar to Alzheimer's disease in humans.

"Cognitive dysfunction syndrome is related to the aging of the dog's brain," explains Gary Landsberg, DVM, BSc, veterinary behaviorist at North Toronto Animal Clinic in Thornhill, Ontario, Canada. "No one knows the exact cause, but beta-amyloid peptides (protein) are present in the brain, as well as an increase in toxic free radicals and possible circulatory problems that contribute to neurons dying off with signs of aging and dementia."

The brain ages like any other organ in the body, resulting in a deterioration of how your dog thinks, learns and remembers, which in turn alters both your life and your dog's.

If you want to test your own dog for this condition, here's an informal test you can conduct on your own.

"Take a dog, show him two different containers, one orange and one green," says Dr. Landsberg. "Cover them up, put food underneath one of them. The dog must learn which container covers the food. Older dogs and younger dogs can get that pretty much the same. Then if you change it, the older dog doesn't get it."

This experiment highlights the point that older dogs have a harder time competing due to deficits in learning abilities.

There are a number of clinical signs of cognitive dysfunction syndrome that include the following:

• Altered response to family members
• Disorientation or confusion
• Difficulty navigating the environment, such as climbing stairs
• Sleep changes
• House soiling
• Activity changes
• Excessive panting
• Restlessness, pacing and confusion
• Agitation
• Reduced interest in food
• Excessive drinking and urinating

Not all dogs that experience this condition will show all of the above signs.

You can help your dog with CDS. Routine activities can be calming to dogs with this disease and make them more comfortable at home. Don't rearrange the furniture as that can be upsetting to an older dog. Get rid of clutter in order to provide wider pathways for your dog that might not be so steady on his feet. Develop a routine schedule for feeding, watering and walking.

If you suspect your geriatric dog might be suffering from CDS, make an appointment with your veterinarian for an examination, along with laboratory tests that include blood and urine, to rule out other possible causes. Any additional tests would only be performed if the veterinarian finds some other problem.

Dean Henricks, DVM, president of the California Veterinary Medical Association in Sacramento, Calif, stresses that while medications and an antioxidant diet can help offset the symptoms of CDS, ultimately there is no cure.

The results of medication and diet are unpredictable. "I have used medication and diet and seen no effect. Then again, I've used the same medications and diet and seen less cognitive deficits," says Dr. Henricks.

"We just finished testing Senilife and Novofit (Sam-e) medications that show improved learning and memory," says Dr. Landsberg. "There is also Selegeline (Anipryl), which has been shown to improve CDS with this drug therapy. These medications are all licensed and tested in laboratories."

If these medications don't work, and your dog is waking up at night, treat the signs and give a sleep aid. It's always a good idea to treat the medical problems, but because they're older dogs, they may also have health issues such as arthritis. Then you need to find new ways to keep them active while treating their arthritis.

In addition to medication, another recommended treatment for dogs experiencing CDS is more physical activity, good food, and more brain enrichment such as food puzzles, games, and agility training. Physical and mental activity keeps the brain active.

Seldom is CDS life threatening in itself, but the disease can affect the bond between dog and owner if your pet is disoriented. You may find that your interaction and you and your dog's quality of life is not what it used to be.

The onset of CDS varies with age. "Not all dogs develop signs of cognitive dysfunction, much as all people don't develop senility," Dr. Landsberg warns. "Some dogs decline as early as six to eight years old, but we may not see clinical signs in a dog until age nine to 11. However, laboratory tests may be able to detect earlier changes."

A veterinarian should see aging dogs without signs of cognitive dysfunction twice a year.  Changes can happen quickly and will be seen in a blood study before you will see any outward alterations in behavior.

Be vigilant and let your veterinarian know of any behavior changes, and don't dismiss CDS behavior as simply old age.

Don't tolerate cognitive dysfunction syndrome longer than is necessary. If you think your dog might suffer from cognitive dysfunction syndrome, seek help immediately. If you wait too long before taking your geriatric dog to the veterinarian, he may become incontinent.  Don't let that happen to your best animal friend.