Why Is My Dog Acting Strange: Changes In Canine Behavior and Habits

Changes in behavior are one of the most misunderstood and overlooked symptoms. In fact, most of the time, behavior changes are not considered a symptom at all.

If you were to remember just one thing, remember this – every change is significant. That absolutely includes any changes in the way your dog acts. Listen to what your dog is telling you.

What would such a change look like?

  • Did your normally friendly and playful dog suddenly become grouchy and snappy?
  • Does your dog no longer enjoy going for walks? Did they suddenly start seeking places to hide, looking to be left alone?
  • Has your dog stopped listening to you?
  • Does your dog no longer get on the bed with you?
  • Does your dog pace around all night?
  • Did your dog start licking at the air and everything in sight?

There is a reason for any of these things.

Why Is My Dog Acting Strange: Changes In Canine Behavior and Habits

Changes in behavior

There is a lot of overlap but things that qualify as changes in behavior include:

  • new aggression
  • unexplained disobedience
  • hiding/withdrawal
  • loss of interest in play or walks
  • obsessive behaviors
  • pacing/restlessness
  • excessive sleepiness
  • loss of housebreaking
  • avoiding touch/grooming
  • changes in vocalization
  • mood changes

Things that fall under changes in routine include:

  • changes in urination and defecation
  • changes in appetite
  • no longer getting on furniture
  • exercise intolerance
  • reluctance to use stairs, getting in and out of vehicle


The most common cause behind changes in behavior or routine is pain. Whether it is from an injury or a disease, surely you don’t want your dog to suffer. Pain can cause any of the above signs or their combination. What signs you might notice depends on how much and where it hurts.

Signs of pain are not always as obvious as crying or limping. It is essential to have your veterinarian investigate and get to the bottom of it. Pain is the first reason you should suspect when your dog’s behavior changes.

Further information: Recognizing Signs of Pain in Dogs: How Do I Tell My Dog Is Hurting?

Jasmine’s example

Before we found out about Jasmine’s arthritis and bad knees, she started refusing JD’s rough play. She got grumpy when he got into her space when resting. We thought it was because he was rather obnoxious, which he was back then. Further, Jasmine lost interest in chew toys and stopped fetching a ball but would fetch flatter objects such as the Flying Squirrel—she had arthritis in her jaw. That’s how subtle the first signs can be.

Back then, we didn’t understand these changes.

To further complicate things, she’d been at the vet often enough that we figured if something were wrong, the vet would have alerted us. But many of our concerns got dismissed.

When I learned to pay closer attention, my frustration grew even higher. At one time, Jasmine started burying her pee. No, I don’t mean ground-scoring; I mean trying to cover up her pee by pushing dirt on it with her nose. Her vet at the time was not listening to me. He just kept repeating that it was normal. Ground-scoring is normal, yes. But that’s not what she was doing. I was unable to get through to him.

It wasn’t until later, with a new vet and Jasmine’s IBD diagnosis and treatment, that she stop doing that and actually started to score the ground instead. We always celebrated when we saw that behavior because, to us, it was evidence of her positive self-assessment.

Some changes scream out loud, such as aggression, while others whisper. The sooner you catch on, the better the outcome for your dog will be. Health problems are always best caught early.

A welcome change that is not welcome

What if your dog’s behavior changes in a desired direction? For example, if your hyperactive dog rests more instead of bouncing off the walls or is no longer running along the fence and barking at anything that goes by?

As much as you might welcome such change, it is still likely a sign of a potential problem.

Besides pain, potential causes behind behavior changes include:

  • a decline in hearing or sight
  • organ dysfunction
  • hormonal diseases
  • neurological disease
  • urinary tract disorders
  • and/or any condition that results in pain could be behind your dog’s behavior changes.

In other words, any change in health status is going to reflect in behavior.

New aggression and irritability

Any condition causing pain or discomfort can lead to an increase in irritability or anxiety/fear of being approached or handled.

A dog with impaired hearing or vision can snap when startled and become more irritable because the world has become a much scarier place.

However rare, rabies should not be ignored as the potential cause of new aggression, irritability, and other changes.

Unexplained disobedience

Dogs can get distracted, too excited, even stubborn, and ignore our requests—that might happen under certain circumstances. But if your dog suddenly stops listening for no obvious reason, consider this:

  • they might be unable to hear you or
  • are unable to comply
  • they are developing dementia (or canine cognitive dysfunction)

Impaired hearing or vision, pain, or severe weakness can prevent your dog from obeying.

Bruin’s example: Towards the end of his life, Bruin started ignoring us when we asked him to do something. He’d just lay there and stare. Loss of hearing could result in disobedience, but his hearing was fine. It wasn’t until he got to the point that we knew the end was near when we learned what was happening. We took him into the clinic thinking it was his time; indeed it was. His heart was so weak the vet couldn’t even detect a pulse. Poor Bruin just didn’t have the energy to do what we were asking of him.


A dog might hide because of fear or anxiety. However, if your dog is normally outgoing and social, and doesn’t have history of anxiety and phobias, the reason they’ll hide is most likely pain or illness.

Cookie’s example: Cookie is an active, outgoing girl who loves fun and attention. The one time she withdrew under the desk and would come out only to go potty, she was diagnosed with pancreatitis. She exhibited other signs but hiding and severe tiredness were the most obvious first signs.

Obsessive behaviors

Compulsive disorders can have root in stress and anxiety. Whatever the reason your dog is stressed out, it is bad for their health.

However, there are medical problems that can result in obsessive behavior as well.

If your dog is excessively licking, scratching, and biting at their own body, you might be looking at:

  • allergies
  • infections
  • foreign bodies
  • pain such as from arthritis etc.

Compulsive licking of surfaces can signify GI upset or disease.

Compulsive eating of inedible objects (pica) can be rooted in

  • GI disease
  • hormonal disorder such as Cushing’s
  • side effect of certain medications such as steroids

Circling can be brought on by:

  • ear infections
  • vestibular disease
  • stroke, or other neurological problem
  • liver failure
  • Cushing’s disease … basically, anything that has an adverse effect on the brain.

Pressing head into corners is a sign consistent with serious neurological disorders, or head trauma and is often seen in hepatic encephalopathy, where the brain is affected secondary to severe liver disease. See a vet immediately if your dog starts head pressing.

Further information:
Excessive Licking in Dogs: Why Is My Dog Licking Incessantly?
Pica in Dogs: Why Is My Dog Eating Non-Food Things?

Loss of housebreaking/potty accidents

A dog who suddenly starts having accidents in the house is not being “bad” but is usually suffering from:

  • a urinary or digestive disorder
  • neurologic issues (particularly cognitive dysfunction),
  • or anxiety

Don’t forget, though, anything that makes your dog severely weak or painful can prevent them from eliminating normally and lead to potty accidents too.

Avoiding touch or grooming

If your normally cuddly dog starts avoiding touch, grooming, or other contact, suspect pain.

Exercise intolerance, disinterest in activity and play

If your dog loses interest in play, walks, and other activities, or hesitates to use stairs, get on furniture, and in and out of a vehicle, suspect

  • pain
  • weakness
Lethargy and unusual sleepiness

Lethargy and excessive sleepiness is an escalation of reduced activity. A lethargic dog is a sick dog. The more severe the lethargy, the more serious the problem.

Panting, pacing, restlessness

Panting, pacing, and restlessness can be sign of emotional distress. However, you need to consider

  • pain/physical discomfort
  • neurological issues
  • cognitive dysfunction

Beware that these signs are also consistent with medical emergencies such as bloat (GDV).

Changes in appetite

While you might be tempted to celebrate when your “chowhound” loses his fixation on food or your picky eater begins eating everything in sight, changes in appetite are associated with a long list of disorders ranging from dental disease, GI conditions to hormonal imbalances.


I cannot list all the possibilities, but the rule of thumb with any change is to look for a medical reason for any behavior change first.

Know what is normal for your dog, be a keen observer, and investigate the cause no matter how deep you might have to dig.

Related articles:
Symptoms to Watch for in Your Dog: The Big Picture

Further reading:
7 Behavioral Changes That Might Indicate Your Dog is Sick
Is Your Dog’s Bad Behavior Caused by a Health Problem?
Behavior Changes in Aging Dogs

Categories: Changes in behaviorCirclingExcessive pantingLethargyPacingSymptomsUrinary accidentsWeakness

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Jana Rade edited by Dr. Joanna Paul BSc BVSc

I am a graphic designer, dog health advocate, writer, and author. Jasmine, the Rottweiler of my life, was the largest female from her litter. We thought we were getting a healthy dog. Getting a puppy from a backyard breeder was our first mistake. Countless veterinary visits without a diagnosis or useful treatment later, I realized that I had to take Jasmine's health care in my own hands. I learned the hard way that merely seeing a vet is not always enough. There is more to finding a good vet than finding the closest clinic down the street. And, sadly, there is more to advocating for your dog's health than visiting a veterinarian. It should be enough, but it often is not. With Jasmine, it took five years to get a diagnosis. Unfortunately, other problems had snowballed for that in the meantime. Jasmine's health challenges became a crash course in understanding dog health issues and how to go about getting a proper diagnosis and treatment. I had to learn, and I had to learn fast. Helping others through my challenges and experience has become my mission and Jasmine's legacy. I now try to help people how to recognize and understand signs of illness in their dogs, how to work with their veterinarian, and when to seek a second opinion. My goal is to save others the steep curve of having to learn things the hard way as I did. That is the mission behind my blog and behind my writing. That is why I wrote Symptoms to Watch for in Your Dog, which has turned out being an award-winning guide to dog owners. What I'm trying to share encompasses 20 years of experience. Dr. Joanna Paul BSc BVSc is our wonderful sponsor and has been kind to edit and fact-check my important articles.

  1. It’s so important to be an advocate for your dog. I know I notice small changes with my cats and share these with the vet when we see him. Cats tell us a lot about how they are feeling if you just watch for signs. The same is true with dogs.

  2. This is such great information Jana, and you’ve covered a broad range. I’m going to keep this handy, it’s very useful. Thanks! Sharing.
    Love & Biscuits,
    Dogs Luv Us and We Luv Them

  3. It is so easy to overlook symptoms in our dogs if we aren’t careful! I appreciate this list so much, because it reminds me to not just take things at face value when it comes to my dogs.

  4. This is so important! We noticed a pretty big shift in my girl Daviana’s behaviour a few years ago which warned us that something was up. Her appetite changed, she wasn’t as interesting in playing as she used to be and she appeared to be tired ALL the time. After a series of tests, we discovered that she had IBD and after addressing it, our playful girl is back again!

    • A great example of how important it is to pay attention and recognize the significance. I’m glad that you figured it out and fixed it. Would you like to share Daviana’s story here?

  5. This is such a great post Jana! It is a cornerstone article as it’s chuck full of great info. Dogs can be so subtle when hiding pain – and even with eyesight loss. Our little guy, who left us a few years back, lost his eyesight overtime. We likely missed signs because he was so used to our home and we didn’t move furniture, etc. But one day – he just stood there shaking. I took him to the vet and viola, he was blind. That taught me the importance of checking eyesight every month with senior dogs. Thanks for this great piece – will share!

    • Thank you, Rebecca. I imagine the signs of gradual sight loss can be very subtle because the dog is learning to work around it while it’s happening.

      I remember a story in one of Stanley Coren’s books, where nobody knew their show dog was blind until they had him groomed for the next show and the groomer cut of the whiskers as well. Because the whiskers are an important tool that was helping him to navigate his environment.

      Would you like to share the story here? It would be valuable to my readers.

  6. I love the check list of what might be the issue when something happens. It is so easy just to say ‘Oh I am glad (s)he is calming down” when there is actually something wrong! Just reading this gave me pause for thought!

    • Thank you. Yes, absolutely, just because you might like the slowing-down, reduction in appetite, less barking or whatever the change might be, it doesn’t mean it’s not a sign of a medical problem.

  7. With Layla aging there has been some changes and I am monitoring them and talk to the vet whenever needed, thank goodness I can email my vet with my questions and she wants to see her she will tell me.

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