The improvements in pet health care are allowing them to live longer and thus be part of our lives for longer. In veterinary medicine, as in human medicine, this longer life means we are starting to see diseases associated with these older pets that we do not see when they are younger.
Cognitive dysfunction syndrome is one of these disorders of elderly dogs. Canines, like people, can have a decline in brain function as they age. I (Perry Jameson) had to deal with this personally in my 14-year-old Labrador retriever, Ariel, before she died last summer.
The changes in Ariel were gradual, slowly occurring over the last two years of her life. Since they were happening so slowly we often did not notice them. It was my in-laws, who did not see her daily, that would point them out to us. The problems we did notice we often chalked up to just her aging and not a true disease process.
Cognitive dysfunction syndrome is a process of gradual cognitive decline. The brain ages like every part of the body and in some dogs this results in decreased function.
Disorientation is one of the main symptoms. With Ariel she would often appear confused or uncertain about what she was going to do next. With a person you can ask what their address is or who the president is, but with dogs we can only watch for changes in mentation. Wandering, pacing, and staring at walls are changes we noted in Ariel.
Another symptom is changes in how dogs interact with people, especially their parents. Not wanting to be petted, not seeking attention, and not greeting people when they came home. Throughout her life Ariel had always wanted to be in the same room as my wife, Holly. Around the age of 12 we noted that she stopped following her around the house. At first we thought this was from her arthritis and not wanting to move, but in hind sight I realize there was more to this change in her behavior.
A change in sleep pattern may be observed with cognitive dysfunction in dogs. They may sleep more during the day but stay awake at night. Ariel would still sleep at night but she was restless, where historically she would sleep in one place, not moving until the morning.
One of the more frustrating symptoms for parents is house soiling. Some dogs will go outside then come back in and immediately eliminate. This is upsetting for everyone as it happens in pets that have been well house-trained for their entire lives. Fortunately this is one symptom we did not see with Ariel.
We did notice a gradual decline in her activity level. Some of this I do feel was from the arthritis she had in her hips and the difficulty she had in getting up and down. However, between the ages of 10-12, when she could not always come outside with us anymore, she would bark until we came back inside. At around 13 years of age this stopped. We could come and go and it appeared to not bother her the way it once had.
You may notice increased anxiety. The chirp of the fire alarm when the battery was low started causing Ariel to tremor in fear. Decreased grooming, change in appetite and decreased response to stimuli also may be observed.
The diagnosis of cognitive dysfunction is based on ruling out other problems which may affect brain function. This can be metabolic diseases such as a low blood sugar or liver failure. Blood tests can help eliminate these. Primary brain diseases such as tumors, strokes or inflammation can result in similar symptoms as well. Your veterinarian can perform a neurologic examination that may detect changes supportive of primary brain disease. An MRI or spinal tap are often necessary to definitively diagnose these primary disorders.
Unfortunately there is no definitive therapy for cognitive dysfunction in dogs. However, there are a few things you can do to improve brain function and slow progression.
Antioxidants may improve neurotransmitter function and lessen free radicals that damage brain cells. There is debate as to how effective they are, but with so few side effects I feel they are always worth trying. The aging dog population has increased enough that some of the pet food manufacturers now make foods with antioxidants to address this problem.
One theory is that there is not enough dopamine in dogs with cognitive dysfunction. Medications to increase dopamine levels appear to help in some but not all dogs.
The brain is similar to other parts of the body in that the more it is used the healthier it will remain. Keeping your dog active and engaged is important. Continue going on walks. Even if they are shorter and slower than in the past they provide mental stimulation and promote blood flow. Treat release toys are another way to stimulate brain function — kind of like you and I doing a crossword puzzle.
We cannot stop this part of the aging process. However, it is important to recognize when our dogs are affected and do what we can to slow its progression.
Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. To send questions, go to Veterinaryspecialtycare.com and click the “ask the pet docs” icon.