There are certain markers we all expect to see in our pets as they age: slowing down, lounging and sleeping more. But there are some actions older pets begin to show that owners may think are normal due to aging that Dr. Amy Pike, chief of the behavior medicine division at The Veterinary Referral Center of Northern Virginia in Manassas, says are not normal and should be brought to the attention of a veterinarian. They are signs of cognitive dysfunction, an ailment that can be treated but not cured.
Cognitive dysfunction is likened to human Alzheimer’s and dementia, says Dr. Pike, and is an age-related ailment found in canines and felines that is a progressive disease with no cure. “We don’t know if there is a particular trigger, they don’t even know what causes it in humans. Is it a genetic trait? A trigger from the environment? Stress? We know it is a very common, non-rare diagnosis. It is a very normal pathophysiology that can happen to any mammal.”
Since cognitive dysfunction is an age-related issue, some owners see symptoms and don’t think there is anything they can do. Not the case, says Dr. Pike. Symptoms for cognitive dysfunction are given the acronym DISHAA and include disorientation, changes in social interaction, sleep/wake cycle disturbances, house soiling, anxiety and activity changes like pacing a lot. Any one of these symptoms can be a marker for cognitive dysfunction. The hard part, though, is determining if that is the ailment manifesting itself or if there are other underlying medical issues.
Dr. Pike says symptoms for cognitive dysfunction are seen in about one out of three pets ages 11 to 12, and two out of three pets ages 15 to 16 years old. But, she notes, it is a rule-out diagnosis; everything medical and behavioral has to be ruled out prior to being called cognitive dysfunction. It is possible for younger patients to show symptoms, but Pike says if a pet shows signs, the diagnosis of cognitive dysfunction is “lower down on my differential diagnosis list.”
Diagnosing cognitive dysfunction is a long process that involves blood work, radiology and potentially other imaging, but patients can benefit from supplements given for symptoms even if they are not truly a cognitive dysfunction case, says Dr. Pike. “We’re going treat the anxiety if there is something going on, whether that be a medical issue or the cognitive dysfunction, and we’re going to benefit that patient by doing these cognitive supplements because they are an older patient.”
The best way to rule out any medical issue—intracranial (brain tumor), endocrine disorders like Cushing’s disease, or diabetes that can mimic some symptoms—is by having blood work and an MRI (brain scan) done, says Pike, noting that this procedure can run anywhere from $4,000 to $5,000. And with the cost, Dr. Pike notes, “Most owners are not going to go for the MRI so we may not necessarily be able to rule out all other medical issues, but the patient is going to benefit regardless with treating the symptoms, and the supplements are not going to hurt them; they can only help them long-term even if it isn’t true cognitive dysfunction we are dealing with.”
Unfortunately, the best way to get a definitive diagnosis is through an MRI.
“We don’t have a lot of great data on ways to prevent the disorder because we’re not doing these long-term prevention studies,” says Dr. Pike. “There can be some of the changes that are seen in human Alzheimer’s where pets get plaque on their brain. We can also see a decrease in cortical (tissue of the brain) size, and an increase in ventricle (spaces in the brain) size—basically the shrinking of the brain due to loss of neurons. Having an MRI would give a definitive diagnosis.”
If an owner does start to see symptoms in their pet, veterinarians can only slow the dysfunction, not cure it.
“We can delay progression,” says Dr. Pike, “and help the [pet] feel more comfortable and get a better quality of life for whatever time they have left.”