Why Has Your Dog Started Misbehaving? [9 Potential Reasons]

Imagine this scenario. You’ve owned your dog for a couple of years, and things couldn’t be better. Your beloved pup has an amazing relationship with every member of your family, and it seems they can do no wrong. Their friendly disposition is a treat for everyone they come into contact with, and friends always tell you they “wish their dog behaved like yours.”

But then…things change.

Your perfect dog starts to regress into an uncontrollable ball of endless frustration. Their behavior starts to spiral. Suddenly, taking them out on neighborhood walks fills you with existential dread, as they consistently yank and pull at the end of their leash. Perhaps you fear leaving them unattended near your furniture in case they gnaw, chew or destroy their way through your couch. Your once happy pup growls, barks or snarls at visitors.

What happened to your dog? Why did they start misbehaving all of a sudden?

As you reflect on your dog’s changed behavior, you should know that two things are true. The first is that dog training is a lifelong endeavor. It isn’t just a one-and-done affair. Every day is a chance for you to build positive habits with your dog – or unintentionally create undesirable ones. The second truth? There is always a reason for your dog’s change of behavior. To manage ‘misbehaving’, we must first understand the source of the change.

In this article, we’ll outline some of the potential reasons why your dog has started misbehaving.

What is misbehaving?

Misbehaving is, in short, any undesirable change to your dog’s behavior. Misbehavior could cover a range of behaviors, from minor irritations like whining or barking, to more serious problems like bullying and aggression that require behavior modification.

Reasons behind a dog’s misbehavior

There are usually triggers or catalysts for a change in a dog’s behavior. Below are some common reasons, but this list is not exhaustive – there may be other factors in your home, your family, or your circumstances that have affected your dog. Speaking with a professional dog trainer can help to pinpoint the reason – or reasons – in your specific situation, and guide you towards a solution.

1) Lack of physical exercise

Under-stimulation is one common reason why dogs engage in destructive behavior. Dog breeds with high energy levels need to be able to expend their pent-up energy, otherwise their boredom can result in them looking for ways to entertain themselves. Ensuring your dog has the right amount of exercise is crucial to reducing the chances of undesirable behaviors.

2) Negative experiences

If your dog has started to misbehave, think back to when it started. Did they have a negative experience with a member of the family, or with another dog? For example, a bad experience with another dog while out on a walk may result in the dog becoming fearful or protective, and this can lead to other changes of behavior.

3) Changes in diet

Food is the fuel that promotes healthy physical and mental development in dogs. Dogs may suffer from digestive problems with a new type of food, and this can lead to malnutrition. This weight loss and lack of nutrients not only affects their physical health, but can also lead to cognitive changes. When changing your dog’s food, consult with your veterinarian, and always make sure you do so gradually.

4) Lack of mental stimulation

Physical health is obviously important – but mental and emotional health in dogs should not be overlooked. A lack of mental stimulation or enrichment can result in your dog becoming bored and finding other ways to entertain themselves. This can lead to unwanted barking or other destructive behavior.

5) Life upheaval & changes in routine

Dogs can be severely impacted by huge changes to our lives. Whether it’s moving to a different home, introducing another dog into the family, having a baby, or a member of the household starting a new job (meaning they are out of the home for most of the day), it can take time for dogs to adjust to the ‘new normal’.

6) Health issues or hormonal changes

Dogs often try to mask physical pain, but if you notice changes to the way your dog is moving (such as avoiding putting weight on a certain paw), it’s possible that they may have an undiagnosed injury. Behavioral changes can also occur as puppies progress through puppyhood and into adolescence, or as older dogs start to suffer from health issues like dementia. If you suspect a health issue may be affecting your dog, speak with your veterinarian to discuss a way forward.

7) Medication or antibiotics

Unfortunately, a remedy for health issues can, in itself, also result in undesirable behavioral changes. When your dog is prescribed medication or antibiotics, the aim is to help fix the underlying issue – however, if you link your dog’s behavioral changes to the point they started taking the medication, it’s possible that there could be a link. Some medications can have side effects for your pet, and antihistamines can often result in either lethargy or hyperactivity.

8) Unintentional reinforcement of bad behaviors

As we said at the outset of this article, every day is an opportunity to train our dogs. If we start to let bad habits creep into their everyday lives, it starts to become normalized. When a behavior becomes normalized, it becomes harder to break. If you don’t act to resolve a problematic or undesirable behavior when it first occurs, don’t be surprised if your dog continues to test the boundaries again and again.

9) Environmental changes

Dogs are extremely sensitive to any changes in the environment. If construction work is taking place near your home, the noise can have a significant impact on your pup’s sense of security. Thunderstorms or fireworks can also cause dogs to behave in unusual ways. Any alteration to their environment – no matter how small or minor it may appear – could be a contributory factor to behavioral changes in your dog. This is why it is essential to try and identify when the behavior started to occur – so you can try and link it to the original catalyst for the change.