Canine cognitive dysfunction syndrome (CDS) is estimated to affect 14% to 35% of all dogs, although exact prevalence is difficult to determine due to difficulty in diagnosis and lack of focused reporting. In a recent report published by the University of Washington Dog aging project, approximately 3% of the 11,574 dogs had a diagnostic score above the clinical threshold for CDS. Most veterinarians agree that about a third of dogs will experience some degree of cognitive decline as they age, perhaps 10% to 20% will progress to CDS.
Symptoms of Dementia in Dogs (Canine Cognitive Dysfunction Syndrome)
Most signs of CDS begin around age 9, with females, especially spayed dogs, susceptible to the disease. Early research indicates that spayed males may develop CDS more rapidly than intact dogs. These findings suggest that hormones may be involved in the development or progression of CDS.
Many veterinarians use the acronym “DISHAA” to help dog owners recognize CDS. DISHAA stands for: Disoriented; Social interaction; Sleep/wake cycle; Dirty House, Learning and Memory; Work; and Worry.
Some of the most common symptoms of cognitive dysfunction in dogs include:
- Wandering aimlessly around the house or yard
- Worry
- Panic
- Urination and defecation in the house
- tempo, most often at night
- Less interaction with the owner
- Does not recognize familiar people, animals, or commands
- Little interest in eating, playing, commuting and socializing
- jitter
- Waking up during the night; increase daytime sleep
- inactive
- Increased voice, often at night
- Approach the left side of a known door
- Unable to locate food that fell on the floor
- Seemingly lost in a familiar environment
Treatment and Complementary Disorders for Cognitive Dysfunction Syndrome
Similar to Alzheimer’s disease, there is no specific treatment for CDS. You can offer your dog a number of lifestyle and nutritional interventions, along with a specific medication.
The drug of choice for most veterinarians facing CDS is selegiline (L-deprenyl) hydrochloride (trade names Anipryl, Eldepryl, Carbex and generic). Cognitive dysfunction is associated with decreased levels of the neurotransmitter dopamine in the brain, and selegiline helps prolong dopamine activity. It also reduces free radicals in the brain, further enhancing its effects.
While not a panacea, I support the use of selegiline in my CDS patients. I usually give the standard dose for two months and if nothing changes, double the amount for another month. If the dog still does not improve, we will stop. About 5 percent of dogs cannot tolerate selegiline. Side effects include vomiting, diarrhea, loss of appetite, itchy skin, tremors, drooling, listlessness, disorientation, hearing loss, or restlessness.
Diets rich in antioxidants and essential fatty acids have been shown to improve cognitive function and slow decline. There are therapeutic diets specifically formulated to support dogs with CDS, including the Hill b/d Prescription Diet and the Purina Pro Plan NC NeuroCare Veterinary Diet.
In addition to a special diet, I recommend DHA and EPA fatty acid supplements. In addition to its strong antioxidant capacity, several studies have concluded that DHA/EPA may help boost brain function.
I also recommend medium-chain triglyceride (MCT) rich supplements, such as Senilife, to my patients with cognitive impairment. MCTs provide an alternative energy pathway for brain cells and may improve mitochondrial activity in neural tissues.
SAMe is on my list of supplements for most older dogs and certainly for those with suspected CDS. SAMe has been shown to reduce clinical signs of CDS and improve executive functions in a few small studies.
Regular aerobic physical activity is essential in helping to slow CDS and prevent mental decline in general. In addition, environmental enrichment is necessary for a healthy dog’s brain. Social interactions, new toys, learning new commands, and engaging in new activities have been shown to help maintain a dog’s brain function and learning ability.
Chloe’s CD Story
“It is difficult to describe. She just seems somehow off. Like she became more absent-minded.”
Sitting across from me was Chloe, a 9-year-old Yorkie lying between a 60-year-old couple in love. This was our first visit, and it was clear that they were extremely nervous.
“Just the other day, when I called her name for a treat, she looked straight at me like she didn’t understand a word I said. I put her favorite cookie on the floor, and she just walked away.”
I have this idea. I gently removed the stethoscope from my neck and dropped it on the floor behind me.
Chloe immediately stood up and looked towards the sound. Okay, her hearing and noise-localization are intact.
“I agree that there might be something wrong. It was a simple test of her hearing and ability to process sensory information. Older dogs often have hearing and vision impairments that lead to the unusual behaviors you describe. Let’s find out what might be causing her symptoms by starting with a thorough physical.”
Both the pet mom and dad breathed a sigh of relief.
“Thanks for trusting us. You’re the third vet we’ve ever seen, and every time we leave it feels like we’ve lost our minds or overreacted.”
“I learned early on to trust pet owners when they say something is wrong. You know your dog better than anyone else. My job is to translate your feelings and my findings into a diagnosis.”
Minutes later, my examination concluded that Chloe was an exceptionally healthy adult dog with no signs of sensory impairment or physical abnormalities. The next step is to do a series of blood and urine tests to rule out any underlying disease as the culprit.
“Pending test results, I would like you to document any unusual behavior or events. Even better, video Chloe if she does anything weird.”
Three days later, I called to inform them that all the tests were normal and to check if Chloe had any more “bad episodes”.
“Doctor. Ward, I think she’s getting worse. Two nights ago, she woke up at 3 a.m. and started wandering around the house. I thought there might be an animal outside, but my husband checked and found nothing. Then today she sat on the potty in the house when I went out.”
I asked her if she had urinated or defecated.
“That’s just it; she did both! I don’t think she’s done it since she was a puppy.
My hunch is that Chloe is in the early stages of canine cognitive dysfunction syndrome (CDS), a condition similar to Alzheimer’s disease in humans. CDS is a degenerative neurological disorder in aging dogs and cats characterized by gradual cognitive decline and increasing changes in brain tissue. CDS is insidious and progressive, and most dog owners don’t realize the changes until they are advanced and severe. Chloe’s parents were right to trust their intuition.
We discussed additional tests, such as magnetic resonance imaging (MRI), to look for additional signs of CDS or encephalopathy, but the owners decided to wait.
During the first month of treatment (see first section of this article for dietary recommendations, supplements, and medications), Chloe’s owner reported no significant events, but she still a bit “slow”. After three months, she had only had a few accidents and her owners were pleased that she was “settled”. A year later, Chloe hasn’t changed.
About a year later, the Chloe family moved in to be near their new grandchildren, and to be honest, I completely forgot about her. One Christmas, the hospital manager knocked on my door, holding a bright red card. Inside is a photo of the couple cuddling a newborn puppy with their grandchildren.
“Doctor. Ward, we would like to inform you that Chloe passed away peacefully a few months ago. She remained cheerful and was able to live on her own until her last days. This is our new puppy, Zoe! I hope she can find a vet willing to listen to her like you did her sister. Thanks again for your help.”
Will not lie; I still read that card when I’m feeling sad. Dog parents, trust your intuition when it comes to your pet’s physical and mental health. You know your dog better than anyone else and they deserve to be heard.
