Symptoms of Canine Dementia

Updated November 21, 2016

Often owners of ageing dogs are alarmed and clueless why their beloved pets stop responding to basic commands, as well as show a drastic shift in personality. The dog that was usually a heartbeat away from his owner now spends time alone and has developed a different personality. However, many times it’s due to canine dementia. According to “Bella Online” editor Sandy Moyer, about one out of three dogs, after age 11, suffer from canine dementia. As in human dementia, many of the symptoms are similar.


Canine dementia is a medical condition known as Cognitive Dysfunction Syndrome (CDS). The disorder causes confusion, disorientation, personality and memory loss. Similar to the human condition known as Alzheimer’s disease, canine dementia is often called doggy dementia, brain ageing, senility or old dog syndrome.


It’s not certain what causes canine dementia, however autopsies show similar types of degenerative brain lesions as found in patients with Alzheimer’s disease. As dogs age, they accumulate beta amyloid deposits, which is a nerve-destructive protein found in the brain. As this starchy protein increases and becomes waxy it creates plaque. This plaque build-up clogs the brain, restraining the transmission of brain signals. The more plaque build-up a dog has, the greater the severity of cognitive damage.

Disorientation, Confusion and Wandering

A demented dog may compulsively walk in circles, circling a table or roaming from room to room, appearing confused and disoriented. Staring at walls for long periods of time is another symptom.


Besides disorientation and confusion, a dog suffering from canine dementia may also stop responding when called. The dog that once loved to respond when told to sit, stay or lie down now draws a blank look and is unresponsive when told to do a basic command.

Indoor Toiletry Accidents

Although your beloved pet may have been potty trained for years, suddenly he starts relieving himself indoors. Besides having frequent toiletry accidents, a demented dog may also stop signalling they need to go outdoors.

Irregular Sleep Patterns and Personality Changes

A dog with canine dementia may exhibit irregular sleep patterns. Usually a dog suffering from dementia will sleep too much during the day and not sleep much at all at night. Because a demented dog can become intolerant and easily annoyed, take extra precaution, not allowing your children to play with him without supervision. If your dog that once loved to be by your side prefers to now spend more time alone, isolated from the family, he could be suffering from dementia.


Larger breeds age more quickly than smaller dogs, with some giant breeds such as Saint Bernards becoming seniors as early as age 5 or 6. On the other hand, smaller breeds rarely show ageing signs before they reach age 10.

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