Why Do Cats and Dogs Fight?

Why Do Cats and Dogs Fight?

Updated October 21, 2021

When it comes to why dogs and cats fight, it’s pretty simple. Dogs think of cats as prey and felines look at dogs as predators. First, let’s start by looking at the difference in their behavior. It’s important that pet owners understand when their cat or dog is stressed out by their new sibling. The advice below is from the cat experts that wrote, “The Trainable Cat.” 

Avoid ‘obvious’ stress 

There is a reason the saying ‘let’s fight as cats and dogs’ exists. So how can pet parents tell when their cat and dog are stressed out with a new addition? 

  • Avoid bringing a dog into the home that is bred to chase or herd. This will be stressful for the cat as he’ll always be on the defensive.
  • Dogs that are overly playful will also pose issues for the cat, watch a dog’s behavior before deciding to bring him into a home with a feline. 
  • Running away or acting with aggression is stressful for any cat, pet owners need to be actively involved in the introductions and have a plan.

Prep: Make adaptations for the environment 

A successful relationship will depend on prudent planning. This introduction can make or break the relationship your two pets have with each other and a little goes a long way. 
  • Teach your cat how to stay safe and provide platforms cats can sit on that a dog cannot access or knock over.
  • You can rearrange furniture so your dog is blocked from accessing certain areas of a room.
  • Sticking cardboard boxes together is a cheap way to make a large hiding structure only your cat can access. 

Keep them separated unless you can supervise 

Cats especially need access to their food, water, and litter box in a safe area of the house that the dog doesn’t have access to. 

  • Give your dog and cat separate living quarters so both are safe while you’re not present to supervise.
  • Having a dog already crate trained is valuable if it’s difficult to find a room only your cat can spend time in while you’re away.
  • The cat must be allowed to approach and explore the new dog on its own, it’s a choice. You also want to manage the greeting. 

We also interviewed Dr. Katherine A. Houpt, VMD, Ph.D. at Cornell University’s College of Veterinary Medicine to learn what can be done. 

why do cats and dogs fight


  • The main reason why cats and dogs fight is because the dog is a predator, and in the dog’s mind, the cat is prey. You must observe their behavior. Those that chase with the intent to kill is the behavior you look for that may result in rehoming one of the animals.
  • They test for this behavior in the shelter, but in some cases, it’s missed entirely. Always have this in the back of your mind when you bring home a new dog or puppy. Work with a trainer or animal behaviorist if you think this is a possibility.
  • If the dog spends time staring at a cat in the carrier when you’re doing safe introductions, then you’re also likely going to have an issue. (In a shelter setting they typically put the dog with a room of cats where you’ll get a different reaction). 

“I’ve had a variety of scenarios. Sometimes you need to separate the cat from the dog. You need a cat tree that the cat can climb up, so the cat is safe. Dogs will react to the front of the cat differently than they will the back of the cat. The front of the cat will be intimidating if their paw is up,” said Dr. Houpt regarding why cats and dogs fight.

If you’re looking for ways to enrich and distract your dog and cat while they’re separated during the day, ask our staff for help!

Here is another article you may want to read before getting a new puppy: Poisonous Plants for Dogs and Cats