Sudden Changes in Behavior

I recently received an email asking for a training referral. The sender had two senior dogs, and the younger of the two was suddenly attacking the older one. There had been problems between the two when they were young, but they’d been getting along for many years. While I did find a trainer for the woman in her city, I also advised her to take both of the dogs in for a complete veterinary exam.

You might be thinking Hmm, a sudden behavior change could be linked to aggressive behavior, but why would she need to take both dogs in? Surely, it’s only the younger one who needs to be seen. While it’s true that the dog who is displaying the aberrant behavior should be thoroughly checked, sometimes the reason the dog has suddenly become aggressive is because the other dog, unbeknownst to the owner, is ill. Think about how in a group of dogs or wolves when the one in charge becomes sick or weak, another member might take advantage of the situation and challenge for rank, especially if his own standing has been suppressed for a while. Dogs often know when another dog is in decline before we do.

Both dogs should have a thorough blood panel done. Vets who are knowledgeable about the effects of physiology on behavior should know what to look for, but it doesn’t hurt to do a bit of research on your own and to share that knowledge with your vet. Check out the link between thyroid levels and aggression, including the work of Jean Dodds, DVM. Look into how issues with the liver can affect canine behavior. Beyond that—and this is something I don’t hear discussed often—I recommend having the dog checked out structurally beyond what normally happens in a cursory veterinary exam. Canine chiropractors are specialists who are much more likely to be able to discern whether a bone is out of place, a nerve is pinched, or something else is happening that’s causing pain or discomfort.

Maybe it’s because I’ve had so many issues with my own back that I understand all too well how, when something is out of place structurally and pain and inflammation strike, anyone can become cranky. Dogs are easily irritated when they’re in pain, and it’s unfortunate that a chiropractic approach is so seldom considered. When my mother was in a nursing home in her late 80s, she kept complaining that her neck hurt. She was clearly in a lot of pain and distress, and though she was normally pleasant and friendly, it made her grouchy and irritable. Who could blame her? The staff kept insisting it was part of what happened “at her age” and just kept pumping her full of pain pills. I told them she needed to see a chiropractor. They wouldn’t listen, and I finally arranged myself for her to be taken to one. One adjustment later and whaddayaknow! The pain was completely gone and she was back to being her own happy self. Doesn’t it stand to reason that something similar could be going on with a dog who was formerly happy and well behaved and is suddenly cranky and aggressive?

Of course, not all sudden aggression has a physiological cause. Changes in the household or the dog’s routine should be considered as well. For example, did someone the dog was close with move out of the home? Did someone new move in? Did a baby arrive on the scene? A change could also be environmental, like a construction site springing up next door. I’m very noise sensitive and can easily understand how a dog who was the same would becoming anxious and might take it out on a canine companion. And what about other senses? Even something like a new cleanser being used in the home could affect an odor-sensitive dog. Chemicals give me raging headaches, and although I haven’t seen any research on the subject, I would think it’s possible that it could happen to dogs as well. And, by the way, it’s not only aggression that can manifest suddenly. If a dog who has seemed fine when left alone is suddenly showing signs of separation anxiety, it may be that he’s feeling needier because he’s unwell or anxious.

Again, many times sudden behavior changes do have roots that are solely behavioral. But when the cause isn’t clear, it’s always best to do some sleuthing to rule out possible underlying factors. After all, if there is a non-behavioral cause, applying behavior modification alone isn’t going to solve the problem. When it comes to sudden behavior changes, a holistic view is always best. And if there’s fighting between your dogs that truly is behavioral in nature, check out my latest book Keeping the Peace for more help.
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12 Responses to Sudden Changes in Behavior

  1. Al G Magaw says:

    well said and very true – my comment is a bit off topic, but it is about “Rank” and how it’s important with any group of dogs, even ‘groups’ as small as two dogs, and how rank can help keep the peace in a group situation – ‘Lyra’ is a 16 1/2 year old retired alaskan husky in failing health – she has a heart that sounds like the swish of a washing machine, and the cough typical with that type of heart problem, and she is very frail – her back legs don’t support her well now and she can’t stand in one position for long without sitting down – in her youth she was one of my main leaders in my best team of sleddogs – when penned with her siblings, this quiet dog always took the first dish at feeding time, her seemingly more robust and pushy siblings never questioning Lyra’s first dish priviledge – I don’t remember Lyra ever getting into a fight, guessing that with her rank, she didn’t have to fight – this past week, we brought 6 year old ‘Nike’ into the house to deal with a weepy eye – of course Nike wanted to meet Lyra – Nike is a niece of Lyra, slightly larger than Lyra, and is one of my best leaders at present – when tottering old Lyra met Nike, who is in the prime of her life, and not the least shy of pushing males twice her size with her front feet when they aren’t responding to a directional command, Lyra’s ears went up and slightly forward – her shoulders expanded subtly sideways, and her frail chest seemed to expand and move forward – ( to my eye, she lost ten years off her appearance ), Nike took a step back in recognition of Lyra’s rank – poor old Lyra was only able to hold the pose for a few seconds before she almost collapsed, but she was able to hold it long enough to establish her rank and thereby keep the peace – had she presented herself as frail and defenseless, it’s possible that Nike might have bullied Lyra – ‘rank’ ( leadership ) in dogs is very important to dogs, as it is in humans, and gaining or losing rank can be grounds for fighting

    • wildewmn says:

      Thanks for sharing that story, Al. It makes me sad to think of your Lyra being so frail now, but good for her that she’s still got the fire in her and was able to stand up and show herself as the leader she still is. Smart girl Nike backing down!

      • Al G Magaw says:

        what impressed me was there was no aggression involved, almost like stripes on an army hat, rank was recognised

  2. Jenny Haskins says:

    I always think of ‘pigeons’ and school playgrounds. Pigeons have a nasty habit of attacking any weak or ill individual in the flock. As do school kids — with kids we call it bullying, though it is probably an evolved selected behaviour to keep flocks and societies healthy. I still don’t like it, though 😦

  3. Cynthia Becker says:

    One of my younger dogs started attacking an older, driving her away and outside through the dog door. The older dog turned out to be in early stages of kidney failure, making her smell different.

  4. I have given that exact suggestion to clients. Even if a dog seems to suddenly get grumpy at home. I find it interesting you mention headaches. I have looked for any studies on headaches in dogs. The reason is I have a St. Bernard/ Pyr mx. He has always at times show the same actions I do when I get a migraine. He puts his head where it is quiet and dark, he squints his eyes. I have asked my vet and she was not sure of any studies. What causes them I am not sure. Check all kinds of things but nothing has been definitive– and let’ face it he is not talking! I have found using CBD oil for them seems to relieve them or ease them up. He actually will go over by the area where I keep the CBD oil looking at it when I come in the room. Do you have any info on headaches in dogs???

  5. Great article, Nicole. Do you have any suggestions on studies between liver ailments and behavior changes? Thanks in advance!

    • wildewmn says:

      Hi Nannette, not sure about studies, but there was a good article in the Whole Dog Journal not long ago about this issue:

      • Steph says:

        Oh this is fantastic…once again, couldn’t see the forest for all the trees. I have long been sure that my younger one has a very intense sensitivity to chemicals (heartworm meds and vaccinations specifically) and have been trying to find a way to balance what is necessary and what is just too much with some luck for many years…will be seeking out an holistic vet to help with this as the girls are now seniors with a few health issues that may very well be the root of the aggression problem (recent standard blood panels and exams have all been ‘normal’ but we shall see) Thank you so much Nicole, commenters and WDJ…I have a renewed sense of hope right now

      • wildewmn says:

        Steph, thanks for sharing that, and I would love to hear what you find out after you’ve seen the holistic vet and whether the behavior changes with treatment. Please feel free to contact me directly through my website if you prefer.

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