(First published January/February 2006 in The Mayor’s Alliance for Mayor’s Alliance for NYC’s Animals newsletter, Out of the Cage!)


Like other older dogs and cats, Bo and Kimberly may experience changes in their cognitive function that could change their behavior.

Like other older dogs and cats, Bo and Kimberly may experience changes in their cognitive function that could change their behavior

Like other older dogs and cats, Bo and Kimberly may experience changes in their cognitive function that could change their behavior

As animals age, they can undergo significant changes in their behavior. Aging of the brain affects multiple aspects of cognitive function, including memory, learning, perception, and awareness. These changes can manifest themselves in different ways, including disorientation, changes in social interactions with owners or other pets, changes in the sleep/wake cycle, or house soiling.

As a result of these changes, a pet might seem lost in a familiar location. Or he/she might have trouble navigating. Or exhibit a personality change, such as becoming more “clingy” or more distant. There might be activity changes, either increased or decreased.  Some pets will pace, or vocalize, while others will become apathetic or stop grooming themselves.

Anxiety might be manifested as irritability or restlessness. Older pets often sleep more during the day while remaining awake at night. Lapses in memory may lead to inappropriate elimination, poor recognition of familiar people, or decreased responsiveness to commands.

Experts estimate that 25 percent of dogs aged 11–12 years and 68 percent of dogs aged 15–16 years will exhibit at least one sign of cognitive dysfunction. This is also true for 35 percent of cats aged 11 years or older. “Cognitive Dysfunction Syndrome” can be diagnosed by exclusion when behavior changes are due to the effects of aging on the brain rather than other medical problems. However, medical conditions or changes in the environment can lower the threshold to where a pet might exhibit behavioral changes.

If you notice any behavioral changes in your older pet, be sure to discuss them with your veterinarian. Remember, treatment options are available. Today, a great deal is known about the various pathogenic processes that affect the aging brain. There are even some parallels between canine cognitive disease and Alzheimer’s disease. If you’re not familiar with toxic free radicals, you’ve probably at least heard the “buzz” about antioxidants. More free radicals accumulate with age while the body’s defenses against them decline. Although the available information regarding oxidative damage in the dog and cat brain is limited, if it does play a role, a diet rich in antioxidants might improve cognitive function. Your veterinarian might recommend a prescription food or a medication called “selegiline.” Some dogs show improvement within the first two weeks, while some not until two months. Stimulation and activity are also important.

There are some natural supplements which you might consider trying on your pet, including ginkgo biloba, melatonin, valerian, or Bach Flower remedies. It’s best to consult a veterinarian familiar with homeopathy before you experiment with any supplement. Pheromone spray (such as Feliway) may have a calming effect on cats as well.

For pets who are severely affected by the aging process, there are veterinarians who specialize in animal behavior. The information for this article is largely derived from the Handbook of Behavioral Problems of the Dog and Cat (G. Landsberg, W. Hunthausen, and L. Ackerman). Thanks to the growing popularity of this field of interest, more resources have become available to general practitioners. Speak to your vet about your pet’s behavior, as well as its health!