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Help, My Dog Is Suddenly Attacking My Cats!

Adrienne is a certified dog trainer, former veterinary assistant, and author of the online dog training course "Brain Training for Dogs."

Don't let the issue of your dog attacking your cat go unaddressed! Let's take a look at some causes and solutions.

Don't let the issue of your dog attacking your cat go unaddressed! Let's take a look at some causes and solutions.

Until dogs can talk and tell us what is going on exactly in their mind, we can only make assumptions as to what motivates them to behave in certain ways. Our assumptions can be more or less accurate depending on how carefully we analyze our dogs' and cats' behaviors and how exposure to certain stimuli or situations may impact them. Following are several possible causes as to why a dog may suddenly start attacking cats.

Reaching Social Maturity

Social maturity is a time when dogs tend to undergo several changes. We tend to see altered dog-to-dog interactions around this age, and this can also occur with other animals sharing the household.

It can simply be that as a dog is maturing, he no longer tolerates certain behaviors from the cats. As puppies, dogs may be accepting of many things, but part of growing up and maturing may entail getting more serious and putting a stop to certain behaviors.

If you own cats that used to push boundaries and bullied your puppy when he was young, now that your puppy has matured, he may no longer be accepting of such behaviors and has decided to rebel.

The Onset of Resource Guarding

As dogs mature, they may also start acting more protective of certain resources. Perhaps your dog no longer wants any cats near the kitchen or nearby his food bowl, or maybe, he doesn't want any cats sleeping on his favorite bed.

A Negative Experience

Unless you are always supervising cats and dogs 24/7, there may be chances that something unpleasant may have happened that made your dog decide that the cats are now his biggest enemy.

Maybe one of your cats has bopped him on the face when you weren't around and this has left a strong impact on your dog or perhaps he was hissed at. Maybe he was scratched on the face or some other place and his fur is hiding the nail marks.

Cats can attack dogs when they are cornered and feel scared. Sometimes cats may attack from redirected aggression or feline hyperesthesia syndrome.

A Medical Condition

Sometimes, when dog behaviors change out of the blue, a medical problem may be the culprit. Perhaps your dog no longer sees well, or maybe he has joint pain which interferes with his mobility and ability to move away from an unpleasant situation. Or maybe, his thyroid levels are low. There are several medical causes that can cause aggressive behavior in dogs.

Sometimes, the cats may too have a medical condition that may cause dogs to lash out. One of my clients once had a dog who started attacking the family cat out of the blue; turns out, only months later the owner discovered that this cat was suffering from occasional seizures. Dogs do not understand seizures, so they may attack the cat as an instinctive response.


Stressful situations can put a dent in the strongest friendships. Dogs and cats (more cats than dogs though) can be very sensitive to changes in their environment. Perhaps, the new construction work across the street is stressing them out, or your cat smells "weird" after seeing the vet or being hospitalized for a few days. Maybe, you recently moved or re-arranged furniture and this has stressed your animals.

Stress can surely play a number on cats and dogs, and stress can wreak havoc even with a few exposures, or it can have a cumulative effect leading to what's known as trigger stacking.

A Matter of Jealousy

In the past, dogs weren't believed of being capable of feeling jealousy because jealousy was perceived as being too complex of an emotion for a dog to feel.

Turns out, jealousy, can turn Rover into a green-eyed monster too. According to a recent study, dogs tend to exhibit behaviors suggestive of jealousy such as getting in between, pushing or snapping.

If your dog attacks the family cat when he is pet or talked to or when he approaches you, this can be a sign of "jealousy."

Dogs can feel a primal form of "jealousy"

Dogs can feel a primal form of "jealousy"

Tips to Stop a Dog From Attacking Cats

To stop a dog who has started to suddenly attack cats, you will need to take a multi-faceted approach. Safety is paramount.

Consult With a Professional

For safety reasons and for correct implementation of behavior modification, enlist the help of a dog behavior professional such as a board-certified veterinary behaviorist (DACVB) or a certified applied animal behaviorist (CAAB) for in-person guidance and couching. Dog trainers who are specialized in treating aggression cases and the interactions between dogs and cats can help too, but make sure they are committed to using exclusively force-free methods.

Make Your Cat's Safety Top Priority

If your dog has suddenly started attacking your cats', then it's imperative to keep your cats as safe as possible. There are many stories of dogs killing cats they have known for many years and never had a problem.

It doesn't make things easy to know that cats seem to not realize that a dog they have known for many years can turn to be potentially lethal to them. Dogs can injure or kill a cat very quickly. On top of this, a dog can also be injured by cats. Cats may aim for the eyes and cause corneal injuries and even loss of vision.

Following are several ways you can keep your cat safe:

  • Install a sturdy and tall baby gate that keeps your cats and dog separated.
  • Keep your dog muzzled when around the cats. Here is a guide on how to train your dog to wear a muzzle.
  • Provide window ledges, high perches and cat trees where your cats can climb up to and feel safe.
  • Place shelves on the walls so your cats can travel around the house without having to get on the floor. There are many plans for vertical spaces purposely made for cats nowadays including walkways and bookshelves with top catwalks.
  • Crate your dog when you are not home or secure the cat in another room.

Prevent Rehearsal of the Attacking Behavior

Dogs are very habitual creatures, so the more they rehearse a problem behavior, the more this behavior puts roots and becomes established over time. This makes the issue more and more difficult to extinguish.

It's very important to prevent your dog from getting into the habit of chasing and attacking your cats. This falls under management strategies.

If your dog attacks your cats for no reason, you are better off preventing your dog from being around your cats as a safety precaution. If your dog attacks only in specific circumstances, you will have to prevent those circumstances from happening, although, there are always some risks that things may change and your dog may still attack, so caution is needed. Here are some management options:

  • Keep your dog away from your cats by using a sturdy baby gate that he cannot climb over, knock down or squeeze under.
  • Keep your cat indoors and your dog in the yard.
  • Keep your dog in a kennel.
  • Keep your dog crated or in a sturdy exercise pen appropriate for your dog's size.
  • If your dog attacks cats around food, feed him in a separated area.
  • If your dog attacks cats around toys, don't keep toys around.
  • If your dog attacks cats out of jealousy, don't give the cats any attention when around him/her.

Implement Behavior Modification

The goal of behavior modification in such a case would be to create positive associations with your cats. This can be done using a mix of desensitization and counterconditioning.

Desensitization requires systematic exposures using baby steps, always ensuring the dog is under threshold.

Counterconditioning entails creating positive associations with the sight of cats. The goal is to obtain a positive conditioned emotional response.

For safety, the dog should be kept initially on a short leash, then on a longer leash and then off-leash while wearing a muzzle and then off-leash without a muzzle, but the cats must have escape routes always handy and a plan should be in place should the dog try to attack or grab the cat (calling the dog, telling him to leave it, telling him to drop it if he manages to grab the cat).

Work should always start with cats at a distance that doesn't evoke the dog's attacking behavior, gradually decreasing the distance as both species allow. If the dog shows signs of trouble, this is a sign that one has progressed too fast. Some steps back in such an instance should be taken, increasing distance and working at the animals' pace and comfort levels before progressing more.

Train Your Dog to Be Responsive

It goes without saying, the importance of responsiveness. If your dog is predisposed to attacking your cat, you need a reliable response to your verbal cues.

Train your dog to respond immediately to a smacking sound with your mouth, to leave it and drop it command, to have a strong, reliable recall, and to lie on his mat.

This training needs to start in low distractions areas, and then distractions need to be gradually added before trying to use them in the presence of cats. Have a dog trainer help you attain these high levels of responsiveness.

Never Let Your Guard Down

As much as your dog is highly trained and despite having formed strong positive associations with your cats, never let your guard down. In other words, think that if the attack happened once, it can likely happen again.

  • Always supervise closely.
  • Manage as much as you can.
  • Prevent situations from escalating.
  • Provide your cats with escape routes.
  • Hold refresher sessions on your dog's training.
  • Have a plan in place to interrupt a potential fight.
  • Never leave the pets alone, not even for a second.

When Things Don't Work Out

Sometimes, despite all our good intent and effort, things may just not work out. Management attempts may fail or it may turn too labor-intensive or the pets may resent it, and when lives are at stake, important decision-making may entail considering re-homing to a loving family if the pet is not a good fit.

If so, don't take it as a failure on your part. Just as it happens among humans, relationships aren't always mean to be lifelong. Forcing things to last, may cause stress and impact a pet's wellbeing. Many dogs and cats are often re-homed when they no longer get along. As heartbreaking as this may feel, sometimes these choices are in the pets' best interest, considering safety and their physical and emotional wellbeing.

If you are debating on whether to re-home your pet, consult with a professional for his/her professional opinion so to ensure you have exhausted all avenues.

Create positive associations with cats. Your dog should be looking at you eager for a treat when your cat is nearby.

Create positive associations with cats. Your dog should be looking at you eager for a treat when your cat is nearby.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2021 Adrienne Farricelli


FlourishAnyway from USA on April 13, 2021:

What a useful article! I only have cats, but when my grandmother was alive, she always had a mix of cats and dogs. Your tips regarding having cat trees and a space where cats can escape for privacy (i.e., use of secure baby gates) is spot on.

Devika Primić from Dubrovnik, Croatia on April 13, 2021:

Such information is always needed and you sure know how to give us the best.

Devika Primić from Dubrovnik, Croatia on April 13, 2021:

Hi alexadry This is why cats and dogs are not friends, Just kidding on that note. Some dogs fight off cats and others grow up together and become friends. You share valuable points and I enjoy learning from your informative and well-researched hubs. You have found your niche and it is important to know about dogs, cats and their behaviors.

Peggy Woods from Houston, Texas on April 12, 2021:

When I was growing up, my family always had dogs and cats, and we have had both at the same time. There has never been a problem. The sage advice you give to those who do have problems may help many people overcome this problem.

Pamela Oglesby from Sunny Florida on April 12, 2021:

I have never had trouble with dogs attacking cats, but my son's dog (who would probably lick you to death) hates cat. If he is near a cat he will it.

Your article gives a lot of good reasons for dogs attacking cats, Adrienne. It is an excellent article, and I think you have provided a wealth of good information.