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Are Dog Worms Contagious to Cats: Here’s What You Need to Know

As I watch my cats and dogs move through life in their love hate relationships, I not only wonder what the deal is with that but also whether or not dog worms are contagious to cats.  Is there any real evidence that cats can get parasitic infections from worms from dogs? 

Golden retriever lying with an orange and white cat on a soft white rug.

Many people are unaware first that your dogs may harbor parasites (see the signs of dog worms here), second, that dog worms may transfer to you and that dog parasites can spread to cats. Let’s look at all of the the facts related to dog worms being contagious to cats.

Different Types of Dog Worms or Parasites

It’s important to note that there are different types of worms that can affect both dogs and cats. However, not all of these worms are contagious between the two species, and not all types of worms are species-specific.

For example, roundworms are a type of worm that can infect both dogs and cats, but just roundworm can spread from dogs to cats, and other types of roundworm are not considered to be contagious between the two species.  Other common dog worms include, hookworms, tapeworms, giardia, and whipworms.

Are Dog Worms Contagious To Cats?

The answer is yes, in some cases dog worms are contagious to cats. For example, hookworms and tapeworms can be passed from dogs to cats. While not all types of worms are contagious between dogs and cats, some are. Ancylostoma braziliense hookworm is a type of hookworm that can affect both dogs and cats and spread from dogs to cats and vice-versa.  

Grey, brown and white cattle dog snuggling with a long haired cat with its neck on the cat's back.
Testing your dog and cat for worms or parasites is important for everyone’s health.

It is important to test your dog and cat regularly for worms and treat as necessary so that hookworms and tapeworms cannot transfer from your dog to your cat and further spread the infection throughout your home.

How Do Dog Worms Transfer To Cats?


While many different types of worms can infect animals, one of the most common is the roundworm which can infect both dogs and cats. Roundworms are parasites that live in the intestines of their host animals.

Roundworms typically enter the body through contaminated food or water or by coming into contact with infected feces. Accordingly, if your cat and dog share living spaces there is plenty of opportunity for the roundworm to transfer.  

Once they’re inside a pet, roundworms begin to reproduce and can quickly grow to large numbers. 

A golden retriever and a white cat lying together on a white plush carpet.
Roundworms can transfer between dogs and cats when they share a living space.

While roundworms don’t usually cause serious illness in adult animals, they can be very dangerous to young puppies and kittens. This is because their immune systems are not yet fully developed, and they can’t fight off the infection as easily. In severe cases, roundworms can cause death.


Other worms, like tapeworms, can be transmitted to cats if they eat infected parasites. Some of the common dog parasites that can spread and cause cats to get tapeworms are fleas, ticks, and mites.

Your dog can get infected by these parasites when he goes for a walk or plays outside and being in proximity to a cat or other animal can transfer the parasite. Therefore, it is important to make sure that your dog is properly groomed and fleas are managed to control tapeworm infestations that can be transferred to cats.


Cats and dogs can get hookworms from their mother or in their environment. When a cat or dog inadvertently swallows larvae, often by grooming its feet, or in drinking water a hookworm infection will become established.

Most larvae that are ingested will move to the intestinal tract to complete their life cycle. A few larvae may make their way into the trachea (windpipe), and are then coughed up and swallowed.

Dogs and cats can pass hookworms to each other through the environment.

An infographic depicting how dogs and cats get hookworms and can transfer hookworms to each other.

How to Prevent a Worm Infestation in Your Pets

There are some steps you can take to help prevent your pet from getting worms. These include:

  •             First, make sure your pet is up to date are up to date on their vaccinations. This will help reduce their risk of exposure to infected animals.
  •             Second, keep your pet’s environment clean. This means regularly cleaning up their feces and keeping them away from areas where other animals may have defecated. If possible, designate a specific area in the house or yard for your dog to relieve itself, and make sure your cat doesn’t have access to this area (we get this can tricky!).
  •             Finally, test your pets for worms regularly and talk to your veterinarian about using medication. This will help reduce the risk of your pet contracting worms, even if they are exposed to them.  Just remember cats and dogs are very different in their ability to handle chemicals. In fact some chemicals commonly used in dogs are potentially very dangerous in cats. Never use dog deworming products on cats.

Taking these precautions can help reduce the risk of your cat getting worms from your dog.  

You may also be interested in learning about Heartworms in our Ultimate Guide to Heartworms, another devastating worm that can infect your pet.

Worms Contagious to Cats FAQs

Are worms contagious to other cats?

Yes, dogs or cats with worms can pass the worms into the environment and those worms can infect dogs and cats.

Should I worm all of my dogs or cats if one has worms?

Deworming medicine, unless it is a natural dewormer, has a lot of chemicals in it. Therefore, it is always safest to test all household pet members for parasites (fecal or stool sample) first prior to treating all household pet members as if they are infected.

How long after deworming will the worms or parasites be gone?

It is important to first select the correct deworming protocol. Deworming for tapeworms is different than hook or round worms. After that it will depend on the type of dewormer used, if you are using a conventional dewormer then it usually will take 2-3 weeks for worms to leave your pets body.

Looking to learn more about taking charge of your Dog’s Health? Learn about Pet Testing from The Popular Pets. Now offering pet testing for your the health of your pet and your peace of mind. Learn more about pet testing options.

You may also be interested in the Ultimate Guide to Heartworm

Diatomaceous Earth for Dogs and Cats FAQ

What happens if my dog sniffs Diatomaceous Earth?

Diatomaceous earth is great for dogs and is safe to ingest and put on their skin, sniffing diatomaceous earth is not a problem but dog owners do need to be careful that dogs do not inhale DE further. The silica in DE can be harmful to dog and cat lungs, especially pets with respiratory issues. The many benefits of DE make it a useful pet wellness tool.

What if my dog licks Diatomaceous Earth?

Since DE is an excellent addition to food due to its ability to kill parasites, bind collagen and support a healthy coat and joints, licking DE is not only beneficial but suggested. DE is safe for dogs but dog lovers should get food grade DE to be safe.

Will Diatomaceous Earth harm dogs?

Diatomaceous earth will not harm dogs. DE is non-toxic and actually helpful for dogs due to its many wellness attributes. Pet lovers have found many benefits to adding DE to their pet’s food to help support a healthy coat and fend off parasites and on externally to help with fleas and ticks.