Cognitive dysfunction syndrome in dogs

Sometimes called geriatric cognitive dysfunction syndrome, the condition is a newly recognized disorder that is somewhat similar to Alzheimer's disease in humans. In dogs with geriatric cognitive dysfunction syndrome, the brain undergoes a series of changes that result in a decline in mental abilities related to thinking, recognition, memory, and learned behaviors. Fifty percent of dogs over 10 years of age have one or more symptoms of geriatric cognitive dysfunction syndrome. Geriatric cognitive dysfunction is a progressive disorder with increasing signs of geriatric (senile) behavior.

Disorientation is one of the principal symptoms of cognitive dysfunction syndrome. The dog seems to get lost in the house or yard, hides in a corner, under or behind furniture, has difficulty finding the door (runs into a jamb or goes through the wrong door), does not recognize familiar people and does not respond to verbal commands or its own name. In such cases, it is necessary to exclude loss of vision and hearing.

Sleep and activity patterns may be disrupted. The dog sleeps longer during the day, but less at night. The level of goal-directed activity decreases and aimless wandering increases. A dog with cognitive impairment may also exhibit compulsive behavior, with circling, tremors, stiffness, and weakness.

In addition, training suffers. The dog may urinate and/or defecate in the house, sometimes even in front of its owners, and may ask to go outside less often.

Often, the relationship with family members becomes less intense. The dog requires less attention, often moves away when petted, shows less enthusiasm when greeted, and may no longer accept members of its family. Some dogs may require human contact 24 hours a day.

Some of these symptoms may develop as a result of age-related physical changes rather than cognitive dysfunction. Medical conditions such as cancer, infectious diseases, organ failure, or adverse drug effects may be the sole cause of these behavioral changes, or they may worsen an underlying medical condition. These medical problems should be diagnosed and ruled out before senile symptoms contribute to the development of cognitive dysfunction syndrome.

Research into the aging canine brain has identified a number of pathological signs that may be responsible for many of the symptoms of cognitive dysfunction syndrome. A protein called beta-amyloid is deposited in the white and gray matter of the brain and forms plaques that lead to cell death and brain shrinkage. Changes in numerous neurotransmitter chemicals have been described, including serotonin, norepinephrine, and dopamine. In addition, oxygen levels in the brain of older dogs decrease.

There are no specific tests to diagnose cognitive dysfunction syndrome. The number of symptoms the dog exhibits and the severity of the senile behavior are important elements in making a diagnosis. An MRI can show some level of brain shrinkage, but this test is rarely performed - only if a brain tumor is suspected. Knowing the diagnosis makes it easier to understand the dog's behavior.

Treatment: The drug Anipryl (seleginil), which is used in humans to treat Parkinson's disease, has been shown to significantly improve symptoms and quality of life in many dogs with cognitive dysfunction syndrome. The medication is given once daily as a tablet. Since drug treatment is now available, it is important to seek veterinary advice if behavioral changes occur in an aging dog.

Additional benefits may be achieved by feeding your dog a therapeutic diet for dogs with age-related brain damage (Hill's b/d). This diet with extra antioxidants was specially formulated for senior dogs. These dogs may also benefit from acupuncture and Chinese herbal treatments.

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