Brain Aging in Pets – Part Two – Symptoms

Symptoms of brain aging, or cognitive dysfunction, are often subtle in their presentation and because of that go unreported. As your pet ages, you’ll need to team up with your veterinarian to be sure your buddy gets the best possible care in their sunset years.

Here’s what you should be looking for. Remember to keep this in mind even if your pet is middle-aged because as we saw in Part One, brain aging begins around that time.


This doesn’t come as a surprise, but as our working memories begin to fail us we notice more and more often that we’ve walked into a room with no idea what we needed. The same goes for our pets. As your dog or cat’s working memory goes they’ll seem more disoriented. Maybe they go into the wrong room at night when it’s time for bed or pass the stairs when it’s time to come down to go outside in the morning.

You may also notice items that used to draw enthusiastic associations out of your pet like your dog’s leash or walking toward the back door for your cat are waning. These kinds of associations don’t disappear all of a sudden but fade instead. As your pet ages, it’ll take longer and longer for the association to be made.

Altered Social Interactions

A landmark aspect of an aging brain is a decrease in frontal lobe mass. The frontal lobe of any brain is where social behavior comes from. Things like empathy, cooperation, and other prosocial behaviors all live in this region of the brain and will start to fade as the mass of the lobe decreases.

In other words, as your pet gets older their social drive will start to fade. They’ll be less motivated to be near you, interact with you, or recognize your emotions. This social decline also happens in humans in the early stages of Alzheimer’s Disease.

Altered or Reversed Sleep/wake cycle

Sleeping is an important part of life and is regulated by the Suprachiasmatic Nucleus. An important piece of anatomy located here is the pineal gland which is responsible for creating melatonin, among other things. Melatonin is made in dim light to aid in the sleep cycle and serotonin is made in bright light to aid in the wake cycle. As we age, the pineal gland can start to calcify making it less effective at its job. This can slowly but surely change the sleep/wake cycle, ultimately reversing them all together.

Today, as I write this, a client called with a question about her newly adopted cat, 12-year-old Silver. She only just adopted him a few days ago and hadn’t spent a full day with him because of her work schedule. Her major concern was his lack of sleep. From the time she gets home in the evening to when she wakes up in the morning, she reported never seeing–or hearing–him sleep.

I actually had to take a minute to be sure I wasn’t coming to this conclusion in error, since just moments before I was working to find out more about pineal gland calcification. Of course, I can’t be sure due to the substantial lack of history that comes with newly adopted pets.

My best recommendation in her case–and for any pet owner noticing this behavior–was to record and report her observations to her veterinarian so they could be sure there wasn’t an underlying medical issue outside of cognitive dysfunction to blame.

House soiling

One of the most commonly reported symptoms of brain aging is not surprisingly house soiling. Unfortunately for pet owners of once fully potty trained animals, proper elimination habits begin to backslide as their pets get older. This is because the emotional motor system, a region in the brain that is responsible for helping us hold our waste until it’s safe to eliminate becomes less effective

You may notice your dog ask to go out less or have less patience once they do. Your cat may have trouble finding the litter box in time, and both dogs and cats might just be confused when they eliminate indoors. Dogs struggling with cognitive decline will be let outside only to come in and have an accident. It’s no wonder house soiling is the most reported symptom of cognitive dysfunction in dogs and cats.

Change in Activity

It might seem like a normal progression for our animals to become less active as they age but, surprisingly, short of arthritis, your buddy should be pretty spunky up until they cross the rainbow bridge. A decrease in activity isn’t always the change you’ll see in your pet. 

Restlessness, pacing, and aimless wandering are also signs of cognitive dysfunction and are often seen in cats.


Other red flags you’ll want to bring up with your veterinarian are excessive vocalization, increased anxiety, a decrease in personal hygiene, and a change in appetite.

Cognitive Dysfunction is a diagnosis of elimination, meaning your vet will need to run a battery of tests before coming to this diagnosis. Be patient with them as they work down the checklist. You can help them by recording in detail your observations of their behavior changes.

Next week’s article is all about what you can do for your pet as they age to help limit the effects of cognitive dysfunction. I’m also going to post bonus material about cat-specific cognitive dysfunction! Come back next week or better yet, sign up for email alerts and get those articles sent directly to your inbox! Don’t miss out! 

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