7 Reasons Why Your Dog Is Acting Scared All of a Sudden

Let’s talk about some reasons why your dog is acting scared all of a sudden. I know it’s a common question among my fellow dog-loving friends.

If your pup is suddenly terrified of his own shadow for no apparent reason, you may wonder what’s gone wrong. Then you might be going out of your mind trying to figure out how to help your scared dog.

Fortunately, I’m here to ease your mind and offer you seven probable causes of sudden fear in dogs.

Related: My dog is acting strange and hiding. Why?

Most Common Signs of Fear in Dogs

These are the most common signs of fearful behavior of scared dogs. It’s far from an exhaustive list. Just as all people experience panic attacks in different ways, so do dogs. One dog may tremble and cower, another may lunge and bark, and yet another may just turn tail & hide.  Still, it’ll give you a general idea of what to watch out for. 

• Trembling
• Avoiding eye contact
• Licking his lips
• Cowering
• Tail tucking
• Hiding
• Lunging, snapping, or other signs of aggression
• Panting
• Circling (or tail-chasing)
• Vomiting or diarrhea

Before we continue, a gentle reminder: If your dog suddenly shows these symptoms, contact your vet. All of these symptoms can also be caused by a myriad of other underlying medical conditions. So, don’t just assume it’s because he’s scared.

Now that we know the signs of fear in dogs, let’s find out what could be causing Fido’s sudden paranoid behavior.

7 Reasons Why Your Dog Is Acting Scared All of a Sudden

One of the worst things for any dog owner is to see their pet cowering in fear without having any clue what’s going on.

Unfortunately, until someone invents a reliable dog-to-human translator, dogs can’t tell you why they’re so scared.

However, if you know how to read your dog’s body language, you might be able to make a pretty accurate guess.

Let’s see what usually makes dogs terrified all of a sudden.

#1 Phobias

One of the most common reasons why your dog is acting scared all of a sudden is a phobia.

Dogs don’t form memories as we do, but they tend to remember negative/positive experiences strongly.

Phobia of noises is very common in dogs and often involves fireworks and thunderstorms. The bright lights, the flashes, and the ear-piercing noise freak dogs out of their minds. 

Usually, a dog with a phobia will pant, whimper, pace, and show signs of anxiety and stress.

In addition to noises like thunder, sometimes dogs develop a phobia of objects or places.

For example, Rover might be reluctant to step into the kitchen or approach the TV. I have a friend with a dog who is terrified of baby gates! 

So something must have startled your pooch so badly that he is afraid to go near the object or the place.

A fearful experience during your daily walk also might make Rover refuse to leave the house and act scared whenever you grab the leash.

In these situations, fear is a learned behavior. So you can desensitize your dog to whatever is frightening him with enough patience and tasty rewards.

Desensitization (also often called counter conditioning) is a science-backed behavior modification technique that uses positive reinforcement training to help your dog learn to associate that which they fear with something good instead. 

For example, if your dog is acting weird and scared due to fireworks or thunderstorms, you can try to get him used to loud sounds by giving him a special treat while the negative stimuli (the noises) are happening. 

To put it in simpler terms,  when the 4th of July fireworks start, give Fido a tasty new bone to chew. 

You could also try to drown the noise with other familiar sounds or relaxing music (like in the video below), but behavior modification really does work best long-term.

Just remember to go slow.

As Debra Horwitz, DVM explains, “The key to effective desensitization is to first find the threshold at which the pet first responds by designing a stimulus gradient (from low responses to high responses) so that the pet can be gradually exposed to progressively more intense levels of the stimulus without the undesirable behavior being elicited.”

Related: My Dog Yelps When Touched. Why is that?

#2 Illness

Usually, a sudden change in behavior is a red flag for most dog owners. Since dogs can’t complain that they’re sick or in pain, they act strangely.

When dogs are not feeling well, they tend to hide until they start to feel better. It’s most likely a survival instinct throwback to their wilder days when being sick or weak could leave them vulnerable to predators. 

However, some pooches might act scared all of a sudden when they are in pain because they don’t know what’s happening to them. You’d be afraid in a similar situation too. 

For example, when my dog sprained her ankle, she didn’t go into hiding. Instead, she came hopping over to me as fast as her hurt paw allowed and gave me her biggest and wildest “I’m really freaked out right now” expression. Whenever she gives me that look, I know she’s not feeling well. 

Observe your dog for other signs of illness such as lethargy, vomiting, diarrhea, fever, or lack of appetite. 

It’s not always a serious medical condition that makes your dog afraid, but you want to get to the root of the problem asap. 

Take a look at some of the other symptoms and warning signs that your dog may be sick:

#3 Separation Anxiety

All dogs bond with their owners. But some pets form such a tight bond that they can’t stand it when their human is away.

This condition is called separation anxiety, and some breeds are prone to it.

Some dogs with separation anxiety bark, howl, and pace whenever they’re left alone. 

Others become extra clingy and seem genuinely in distress when it’s time for their human to depart. 

Often, dogs with separation anxiety act destructively when the owner is away.

That’s why owners often overlook it as a behavior problem. Some even resort to punishment (which you should never, ever, ever do)! But your dog is really suffering and can’t help his actions.

So, if your pooch is acting scared all of a sudden when you’re about to leave the house, it might be due to separation anxiety.

You’ll have to teach your dog that being alone is not a bad thing. Again, counter-conditioning and desensitization techniques come in really handy with that. 

Professional trainer Zak George has great tips on dealing with separation anxiety, so check out his video below.

#4 Past Abuse or Traumatic Experience

When you adopt a rescue dog from a shelter you often don’t learn their whole history and what they’ve been through.

Your dog might have been abused by his previous owner, and as such, Rover might get scared when something reminds him of his ugly past.

For example, your pooch might get scared when you sound angry or when there’s tension in the house.

Accidentally stepping on your dog’s tail or paws also might make your dog terrified all of a sudden.

Particular smells, tone of voice, or hand gestures also could trigger an episode of sudden fear.

Your dog might even get shy around strangers if they remind Rover of somebody who abused him.

Even a dog who had a wonderful past may act scared when you first bring him home. A new environment can be very overwhelming for any creature. Heck, even I get a bit scared when I have to go someplace strange! 

In these situations, you’ll have to earn your dog’s trust and work on desensitizing him to the triggers.

Again, Zak George is a great resource for training a scared dog. Take a peek at his tips below.

#5 Something Strange in the Environment is Scaring Your Dog

It’s a well-known fact that dogs have a remarkable sense of smell and that their hearing is far more sensitive than ours.

So when your dog is suddenly afraid, I say that you should check what’s happening outside your window.

There might be a construction crew making loud noises. Or perhaps there are other dogs or predators in the vicinity. Your pooch might be acting weird and scared because he has picked up their scent. Chasing the intruders away will usually calm down your dog.

You might also have mice, termites, or other vermin in the house. Some dogs might be afraid of vermin and act scared whenever they catch their scent or hear them moving in the walls.

In addition to this, your dog may be reacting to something you can’t hear.

For example, some owners have reported that thunderstorms miles away affect their dogs’ behavior.

Other pet owners say that their dogs and cats acted oddly in the minutes or seconds before the ground start shaking.

#6 Age-related Problems

When dogs get older, their senses are not as sharp as before. Many elder pets have trouble orientating around the house.

That’s one possible explanation of why your dog is scared all of a sudden.

Furthermore, sometimes older dogs get dementia. These dogs don’t know where they are and what’s happening.

If that’s happening to your pooch, he is bound to be scared out of his mind.

Other possible signs of dementia in dogs include aimless wandering, loss of direction, mood swings, aggression, and staring off into space.

While there’s no cure for canine dementia, there are medications that can help.

#7 Lack of Proper Socialization

Last but not least, sometimes dogs get scared all of a sudden because they haven’t been socialized properly.

During the socializing process, puppies explore the world so that they become comfortable with all kinds of people and objects.

However, not all dogs get properly socialized. As a result, your dog might be scared all of a sudden because they’ve encountered something they haven’t been introduced to.

For example, some dogs might be afraid of people with glasses or crying children. An unsocialized dog who has only ever spent time with women may fear men, and vice-versa. 

If you think poor socialization could be the culprit behind your dog’s sudden fearful behavior, consider enrolling in a training course.

Should I be worried if my dog is acting strange?

Should you be worried? Yes. Is it always something worth worrying about? No. Confused? Let me explain. 

Any time your dog starts acting strange out of the blue, it’s a good idea to worry enough to call your vet. That goes for a dog suddenly jumping at her own shadow, developing a habit of hiding under the bed at every sound, or just plain acting like anything except her usual self. 

There’s a really solid chance that a checkup won’t reveal anything out of the ordinary. Dogs act strange for SO many reasons, as we just saw above, and very few of them have anything to do with life-threatening illnesses. 

While dogs don’t always act differently when they’re sick, nor are they always sick when they’re acting differently, there’s enough correlation between the two to make it always worth investigating. Does that make sense?

FAQs about Fear in Dogs

Let’s quickly go over a few of the most frequently asked questions about fear in dogs. 

Conclusion

Dogs might get scared for many reasons, and it’s not always easy to identify the culprit.

But once you do, you can work on getting your dog the help he needs to live a life free of fear.

Dogs might get scared for many reasons, and it’s not always easy to identify the culprit.

But once you do, you can work on getting your dog the help he needs to live a life free of fear.

What do you think about these reasons why your dog is acting scared all of a sudden? Tell us in the comments.