We know that hearing and mental abilities decline in both humans and dogs with increasing age, and human age-related hearing loss is a large risk factor for the development of dementia. But a recent study from North Carolina State University shows that for senior dogs, hearing loss predicts a greater risk of dementia.
One-third of people over the age of 65 experience hearing loss and the rate of cognitive decline is approximately 30 to 40 percent faster in people with hearing loss, reports Psychology Today. The canine version of this kind of dementia is known as Canine Cognitive Dysfunction (CCD). While many factors have been implicated as contributing to the risk of dementia, one that is not well-known is hearing status.
Telltale Signs of Doggie Dementia
The study, published in the Journal of Veterinary Internal Medicine, evaluated 39 senior dogs. Auditory and cognitive tests were performed on each dog and their parents were asked to fill out two questionnaires. The first evaluated the quality of life of the dog. (Quality of life is often lower in humans with dementia.) Questions inquired about the dog’s vitality (such as whether the dog showed a lack of energy or was still doing its favorite activities) as well as the quality of companionship (such as showing a normal amount of affection and enjoying being petted and touched).
The second questionnaire directly looked for symptoms of CCD. Questions asked about whether the dog appeared to be disoriented in familiar environments, had difficulties recognizing familiar people and animals, or showed a reduced ability to remember and respond to commands that it had previously learned.
The researchers compared the hearing scores with the quality-of-life scores and found that vitality and companionship behaviors decline significantly as hearing ability deteriorates. Other researchers have determined that hearing loss is one of the largest risk factors for dementia in people.
A Treatable Condition
Natasha Olby, researcher and author of this new study, said it indicates the same connection between hearing loss and dementia in aging dogs, “but since we can potentially treat hearing loss in dogs, we may be able to alleviate some of these other issues,” she said. The researchers say their work could aid in both treatments of aging dogs and in understanding the relationship between sensory loss and cognitive function in dogs.
