As dogs age, their brains undergo changes just like humans do. This can lead to a condition known as canine cognitive dysfunction (CCD), which is characterized by changes in consciousness and behavior, as well as a gradual loss of the ability to remember or learn new things. It is a common disorder among older dogs, with about one in three dogs over the age of 11 showing at least one clinical sign of the disease. By the age of 16, almost all dogs suffer from some form of canine dementia.
Unfortunately, many owners do not discuss changes in their geriatric dog’s behavior with a veterinarian because they believe these problems are a natural and incurable aspect of aging. However, the neurodegenerative changes that occur in the brain of an older dog are progressive, which means that the sooner they are detected, the more effectively they can be corrected or at least slowed down.
Sarah Yarborough of the University of Washington and colleagues conducted a new study on the prevalence of CCD in a large sample of companion dogs. All owners were part of the Dog Aging Project, a longitudinal study of domestic dog aging in the United States. A total of 15,019 dogs were included in the sample and categorized according to their position throughout life. In total, 20 percent of the dogs were in the last quartile of their lives, 24 percent were in the third quartile, and 27 and 29 percent were in the second and first quartiles, respectively.
Between December 2019 and 2020, pet owners completed two questionnaires: the “Health and Life Experience Questionnaire” (with information on health status and physical activity) and the “Canine Social and Learning Behavior Questionnaire”, which included questions to check for symptoms of CCD for example, whether the dog did not recognize familiar people or showed memory loss. Data from these surveys showed that 1.4 percent of dogs were classified as having CCD.
A study published in the journal Scientific Reports found that when looking at age alone, the likelihood of a dog being diagnosed with CCD increases by 68 percent for each additional year of life after the age of ten. When controlling for other factors, such as health issues, spaying, activity level, and breed type, the likelihood of developing CCD increased by 52 percent for each additional year of life over the age of ten.
The researchers also noted that for dogs of the same breed, age, health condition, and neutering, dogs that their owners said were inactive were 6.5 times more likely to develop PCD than dogs that they said were were active. However, the experts warn that their study does not show a causal relationship between inactivity and CCD due to its crossover nature, and cognitive decline may be a factor leading to reduced activity.
The researchers suggest lifespan assessment could help veterinarians determine if dogs should be tested for CCD when they come in for other health checks. They also conclude that further research is needed to better understand CCD.