
If you worry that your dog’s strange behavior could be a sign of something serious, we want to help you get to the bottom of the problem, so we compiled this thorough guide, which will go over some of the most common reasons why dogs act weirdly.
Not only will we help you identify what the weird behavior means, but we will also offer some advice you can follow to help your canine companion get back to normal. While some behavioral changes are minor issues and could just be a natural sign of aging, others are more serious and could even require immediate medical attention.
Remember, as a dog owner, it is important that you do everything in your power to look after your pooch. By learning to recognize issues as soon as they present themselves, you will be helping your dog live a long and healthy life!
Table of Contents
- Why Is My Dog Acting Weird – The Top Causes

Why Is My Dog Acting Weird – The Top Causes
Your Dog Could Be Experiencing Separation Anxiety
Unfortunately, dogs are susceptible to canine separation anxiety. They are extremely social animals that tend to form very tight bonds with the families that raise them.
If a dog has become accustomed to spending time with you or other members of your household, then they suddenly disappear for long periods, this can cause severe anxiety and stress, which is often dubbed “canine separation anxiety” by veterinarians and dog behaviorists.
Typically, this issue is demonstrated by several behavioral changes. You may notice the dog seems extremely anxious while you are away or as you prepare to leave the house for the day. These distressed behaviors could include increased vocalizations like incessant barking and whining, destructive behaviors like gnawing on furniture, scratching carpets, intentionally destroying toys, or even defecating and urinating indoors.
When dogs are suffering from separation anxiety, they also become significantly clingier while you are home. They may even become territorial, meaning they will growl and bark as others approach you.
You may also notice an increase in fear-related behavior before you leave the house. This could include shivering, excessive salivating, or a bowed head and lowered tail.

What Causes These Behavioral Changes?
If you are wondering why your dog is suddenly suffering from canine separation anxiety, you have to ask yourself what changes have occurred in your own life. Are you working longer hours? Did you recently change jobs or switch from a work-from-home position to an in-person position?
Dogs that are not properly socialized will often suffer from separation anxiety. It is of vital importance that your dog learns how to be on their own from a young age.
What Can You Do if You Suspect Your Dog Is Suffering from Separation Anxiety?
As is often the case with any type of severe anxiety issue, you may want to start by speaking with a veterinarian, as they can assess your dog and come up with a tailored plan you can follow.
With that said, the following actions can also help your dog overcome their anxiety issue:
- Spend quality time with your dog when you are home. This means going on lengthy walks, playing backyard games, and even just cuddling up.
- Try to establish a more predictable routine. Since your dog is anxious about being left alone, the more stable your routine is, the less they will worry that you will not return.
- Slowly condition your dog to spend more time alone. This can be something you can work through with a professional obedience and socialization trainer.
- If the problem is severe, speak with your veterinarian about anxiety relief medications, supplements, and diets.
If you have more questions about separation anxiety and other common dog behavioral issues, this helpful guide from the ASPCA titled Separation Anxiety is an extremely helpful resource.
Physical Injury or Potential Illness
Since dogs cannot simply express their pain and discomfort to us using words, they often communicate these problems through changes in behavior. These behavioral changes can present themselves in many ways, so always pay attention to how your canine companion is acting.
These weird behavior changes could include extreme lethargy, changes in eating and drinking habits, irritability, antisocial behavior, and more obvious physical signs of injury, like limping, whimpering, and lowered eyes.
Illness is also demonstrated with changes in behavior. Like with physical injuries, behavioral changes can vary. Pay attention to how your dog eats and sleeps and if there are changes to the way their stool looks to make sure they don’t have a health problem.

What Causes These Changes in Behavior?
As mentioned above, your dog cannot simply explain how it is feeling, so they just demonstrate injuries and illnesses through their behavior. Think about how you act when you feel sick or have a painful injury.
While the behavioral changes may seem annoying and strange to us, they could signal that something severe is wrong with your pooch.
What Can You Do if You Suspect Your Dog Is Suffering from Injury or Illness?
First, take note of all the behavioral changes you noticed and try to recall when they first started to appear. This information can be very useful for a veterinarian as they are assessing your dog.
You can perform a quick physical inspection of your dog to check for obvious signs of injury, like cuts, broken teeth, ripped nails, or lumps along the skin. From there, check for obvious signs of dehydration, a symptom that often accompanies illness. Check the gums to ensure they are pink, rather than white, and check that the nose is not dry.
From there, the most important thing you can do is take your dog to see a veterinarian. Offer the veterinarian all the information you know, as this can be very valuable as they determine what is wrong with your dog. Once the veterinarian has assessed your dog and determined the cause of your dog’s behavioral changes, follow their advice to do everything you can to make sure your dog feels better!
For more information about illnesses that could cause your dog to behave in strange ways, consider reading the following article from the American Kennel Club (AKC): Common Canine Diseases.
Canine Cognitive Dysfunction
Unfortunately, as dogs reach their senior years, many start to decline in cognitive abilities. While this is sad, it is a fairly natural process. Brain function can slowly deteriorate in a senior dog, which can cause memory loss, brain fog, and chronic confusion.
As you can imagine, a decline in cognitive function almost always presents with noticeable changes in behavior. You may notice that senior dogs bark more than they used to, that they often seem to just stare off into space, or they seem to forget basic commands they used to be able to perform with ease.
What Causes These Changes in Behavior?
Age-related cognitive decline can impact dogs just as much as it can impact humans. Dogs will suffer memory loss, which can change the ways they behave. They may forget routes home that were once really easy, commands they used to do with ease, or even where they left a favorite toy or treat.
In some cases, what seems like cognitive dysfunction could be other age-related issues, like partial sight loss, hearing loss, or even just simple joint pain.
What Can You Do if You Suspect Your Senior Dog Is Suffering from Cognitive Decline?
The first thing you should do is stay calm and try not to get angry if your dog makes seemingly simple mistakes, like having accidents in the house or barking at night. The dog could be extremely confused, and getting angry will only make your dog feel scared.
By staying calm and trying to reassure your dog positively, you can avoid adding anxiety to your dog’s existing issues. From there, you need to book an appointment for your dog to visit a veterinarian for an assessment.
While there is no cure to halt the cognitive decline, many medications, supplements, and specialized diets can help to slow the progression of the issue. Your veterinarian will know what will help treat your dog’s specific issue, which is why it is so important to book an appointment as soon as possible.
If you want to know more about canine cognitive decline and other related issues, PetMD has a useful guide titled Dog Dementia – Symptoms, Causes, Treatment, and Life Expectancy.
Other Potential Causes of Strange Behavior in Dogs
While the three causes listed above tend to be the most common, there are plenty of other issues that could be causing the changes in behavior you notice in your pooch.
The following are also worth looking into:
- Severe allergies
- Hormonal changes related to age and life stage
- Changes in environment
- Boredom resulting from a lack of mental stimulation
- Obesity and unhealthy weight gain