Things to know about Canine Cognitive Dysfunction (CCD) in Dogs?

Just like humans with dementia, dogs frequently show signs of cognitive decline or dysfunction (CCD) as they age. In fact, CCD is the canine equivalent of Alzheimer’s disease (AD). With both diseases, neurotoxic proteins accumulate in the brain and these plaques, along with cerebrovascular disease (compromised brain vasculature), contribute to the brain impairment that is a hallmark of these disorders.

Fortunately, dogs with CCD seldom show the severity of cognitive dysfunction seen in humans with Alzheimer’s disease; however, even mild or moderate changes can make living with affected pets difficult. When dogs have memory loss, they may urinate or defecate in the house because they don’t remember how to get outside, or they forget where the appropriate place to urinate or defecate is. They may exhibit anxiety and they may become less interactive with their owners.

Some affected dogs may develop sleep disturbances (they are active and may vocalize at night, but they sleep during the day). They may also develop a loss of motor function and forget how to do things that they were taught as a puppy (how to sit or stay). In a word, these pets show signs of becoming senile.

Although dogs with CCD are typically recognized as showing cognitive impairment by 8 years or older, there is considerable evidence that the processes leading to this clinical state begin earlier in life. Pet owners and veterinarians should therefore consider brain-healthy habits (diet, enrichment, exercise and regular check-ups) when dogs are middle aged, rather than waiting for signs.

How common is CCD?

According to Dr. Curtis Dewey, a veterinary neurologist with extensive knowledge on this subject, estimates of the prevalence of CCD generally vary between 14% and 35% of the pet dog population, in dogs 11-12 years old 28% and in dogs 15-16 years old 68%; however, he notes that those percentages are likely an under estimation of how common the disorder is.

As with people with AD, the prevalence of CCD increases dramatically with age. Dogs may show evidence of brain changes as early as 6 years of age. Furthermore, many dogs with mild impairment will progress to moderate impairment and those with moderate disease often progress to severe impairment.

Is CCD treatable?

Fortunately, dogs with CCD are less likely to develop such severe impairment as occurs in people with AD.  Affected dogs typically respond well to medical intervention, especially if instituted early in the disease process. There is also evidence in both AD and CCD that preventive measures such as dietary changes and environmental enrichment can both delay the onset and slow the progression of cognitive decline.

For pet dogs approaching middle age, the measures that have been studied for CCD – diet, mental enrichment and regular exercise – are reasonable to build into daily life. Talk with your veterinarian about what fits your dog, and raise any change in behavior at each visit.

Diagnosis

Your veterinarian will make the diagnosis of CCD based on your dog’s breed, age, sex, the history you provide (which is critical to the diagnosis), and some clinical features that are consistent with this disease. Occasionally, advanced imaging (MRI) may be considered to rule out other causes of abnormal behavior such as a brain tumor.

Treatment

Diet

In both human AD and CCD of dogs, diet has been studied as a factor in the development and progression of cognitive decline. Both dietary risk factors and preventive factors have been identified for AD in people, and these are suspected to be similar in CCD.

Diets enriched with carnitine, lipoic acid, long-chain omega-3 polyunsaturated fatty acids, vegetable-based carotenoids, vitamin E, and vitamin C may be of benefit. Medium chain triglycerides (MCTs) may also be beneficial as a supplement for these dogs as they provide an alternative energy source for the brain in cognitively impaired patients. There are several commercial diets available that contain some of these dietary supplements. 

Several nutraceuticals, including curcumin, S-adenosylmethionine (SAMe) and phosphatidylserine, have been studied in aging dogs, mostly in small trials. None of these ingredients is an approved treatment for CCD; your veterinarian can tell you whether any of them fits your dog’s plan.

Chinese Herbal Therapy

In recent years, Chinese herbal medicine has been investigated in experimental (rodent) AD models and in human AD clinical trials. Herbs that have been studied include Ginkgo biloba, Huperzia serrata, Curcuma longa, Ginseng, Polygala tenuifolia, Salvia miltiorrhiza, Epimedium and Scutellaria baicalensis. Most of that research is in rodents or people rather than dogs, and none of these herbs is an approved treatment for CCD.

Cognitive Enrichment

Cognitive enrichment, such as regular exercise, social interactions, and introduction of new toys, has been shown to improve cognitive function in dogs with CCD and prevent or delay cognitive decline in dogs as they age.

Where to go next

If you are seeing changes in an older dog, start with our dog dementia guide, which covers the signs, the stages, how veterinarians diagnose CCD and the care options they use, and bring your notes to your next veterinary visit.