Are Worms in Dogs Contagious to Other Dogs? What Every Pet Parent Should Know

September 17, 2025 |

Parasites are not just unpleasant: they can be downright dangerous for dogs. But one big problem with parasites is that it can be hard to tell if your dog is infested. The symptoms of worms in dogs can be similar to those caused by other conditions, which means you need to know what to look for. Read on to learn more about worms in dogs, and how to treat them.

If you’re a dog owner like me, the thought of your furry friend having worms probably makes your skin crawl Trust me, I get it! But what’s even more concerning is wondering if one infected pup can pass those nasty parasites to your other dogs. Well, I’ve done some digging into this topic, and I’m here to share what I’ve learned about whether dog worms are contagious to other dogs.

The Quick Answer: Yes, They Are Contagious

Let’s not beat around the bush – yes, worms in dogs are highly contagious to other dogs. But before you start panicking and separating your pets, you should know that transmission isn’t as simple as your dogs just being in the same room together. Worms spread through specific ways, and understanding these mechanisms can help you protect all your furry family members.

Common Types of Worms That Can Infect Your Dog

Before we dive deeper into how worms spread. let’s quickly look at the main culprits

  • Roundworms: These are the most common parasites in dogs, especially puppies. They live in the intestines and can grow up to 12 inches long! Yikes!
  • Hookworms: Small but dangerous, these worms attach to the intestinal wall and feed on your dog’s blood.
  • Tapeworms: These flat, segmented worms are often transmitted through fleas.
  • Whipworms: These live where the small and large intestines meet and can cause serious inflammation.
  • Heartworms: Unlike the others, these are transmitted by mosquitoes and live in the heart and blood vessels.

Each type has its own life cycle and way of spreading, but they all pose health risks to your dog if left untreated.

How Do Worms Spread Between Dogs?

Worms don’t jump from one dog to another through casual contact or breathing the same air. Instead, transmission happens through these main routes:

1. Contaminated Feces

The most common way worms spread is through contact with infected poop. When a dog has worms, the parasite eggs are shed in their feces. If another dog sniffs, licks, or ingests something contaminated with these microscopic eggs, they can become infected too.

2. Contaminated Environment

Worm eggs can survive in soil, grass, and other surfaces for months or even years! This means your dog could pick up worms from the dog park, your backyard, or anywhere an infected dog has pooped before.

3. Mother-to-Puppy Transmission

Some types of worms, like roundworms, can be passed from a mother dog to her puppies during pregnancy or through nursing. This is why puppies are so commonly affected by worms

4. Intermediate Hosts

Some worms require an intermediate host in their life cycle:

  • Tapeworms are typically transmitted when dogs ingest fleas
  • Heartworms are spread by mosquito bites

Warning Signs That Your Dog Might Have Worms

How do you know if your dog has worms? Here are some common symptoms to watch for:

  • Weight loss despite normal or increased appetite
  • Potbellied appearance, especially in puppies
  • Diarrhea or vomiting
  • Visible worms in stool or vomit (they might look like small white segments or spaghetti)
  • Scooting their butt across the floor
  • Dull coat and lack of energy
  • Coughing (especially with heartworms)
  • Bloody stool (with hookworms)

If you notice any of these signs, it’s time to call your vet. Remember, some infected dogs show no symptoms at all, which is why regular vet checkups are super important!

Should I Treat All My Dogs If One Has Worms?

This is a question I get asked a lot, and the answer is generally yes. Here’s why:

  1. Worms spread easily between dogs living in the same household
  2. It’s nearly impossible to keep dogs from sharing water bowls, toys, and spaces
  3. By the time you notice symptoms in one dog, others might already be infected
  4. Prevention is easier than dealing with a full-blown infestation in multiple pets

Even if your other dogs aren’t showing symptoms, they could still be harboring worms. Most vets recommend treating all dogs in the household when one tests positive. Treatment usually takes up to four weeks, and during this time, reinfection is always possible if not all pets are treated.

Can Humans Catch Worms From Dogs?

While this article is primarily about dog-to-dog transmission, I’d be remiss not to mention that yes, some types of dog worms can infect humans. This is especially true of roundworms and hookworms.

However, you won’t get worms from your dog licking you. Transmission to humans typically happens when we accidentally ingest worm eggs (like if you touch contaminated soil and then touch your mouth) or when hookworm larvae penetrate bare skin (like walking barefoot in contaminated areas).

Children are at higher risk because they’re more likely to put dirty hands in their mouths or play in areas where dogs might have pooped.

How to Prevent Worms in Your Dogs

Now for the good news – worm infections are preventable! Here are some practical steps you can take:

1. Regular Deworming

Work with your vet to establish a deworming schedule appropriate for your dog’s age, lifestyle, and risk factors. Puppies need more frequent deworming than adult dogs.

2. Year-Round Preventatives

Many monthly heartworm preventatives also protect against intestinal parasites. Using these year-round can significantly reduce your dog’s risk of getting worms.

3. Prompt Poop Pickup

I know it’s not the most glamorous job, but picking up your dog’s poop promptly is one of the best ways to prevent the spread of worms. This is especially important if you have multiple dogs or frequent dog parks.

4. Flea Control

Since fleas can transmit tapeworms, keeping your dogs flea-free is an important part of worm prevention.

5. Regular Vet Check-ups

Annual or bi-annual check-ups should include fecal testing to detect worms, even if your dog isn’t showing symptoms.

6. Good Hygiene Practices

Wash your hands after handling your pets or their waste, clean food and water bowls regularly, and wash pet bedding frequently.

Treatment Options for Dogs With Worms

If your dog does get worms, don’t worry – they’re treatable! Your vet will likely prescribe a dewormer specific to the type of worm your dog has. These medications are usually quite effective and work by either paralyzing the worms or disrupting their digestive processes.

Some treatments require multiple doses to catch all stages of the worm’s life cycle. It’s super important to follow your vet’s instructions exactly and complete the full course of treatment.

How Long Can Dogs Live With Worms?

This is a scary question, but it’s one that many pet parents wonder about. The truth is, it varies depending on:

  • The type of worm
  • The severity of the infestation
  • Your dog’s overall health and age

Some worms, like roundworms, can live inside a dog for years without causing death (though they definitely affect quality of life). Others, like hookworms, can cause deadly anemia in just a month if left untreated, especially in puppies.

The good news is that most worm infections are treatable when caught early. That’s why regular vet check-ups are so important!

Final Thoughts

As a dog owner with multiple pups at home, I understand how worrying it can be to discover one of your dogs has worms. The possibility of it spreading to your other furry family members adds another layer of concern. But knowledge is power, and now you know that while dog worms are indeed contagious to other dogs, there are clear steps you can take to protect all your pets.

Remember: prompt treatment, good hygiene, regular preventative measures, and routine veterinary care are your best defenses against these pesky parasites.

Have you ever dealt with worms in your dogs? How did you handle it? I’d love to hear your experiences in the comments below!


Disclaimer: While I’ve researched this topic thoroughly, I’m not a veterinarian. Always consult with your vet for proper diagnosis and treatment if you suspect your dog has worms or any other health issue.

are worms in dogs contagious to other dogs

What harm can worms do?

​​If left untreated, your dog can become seriously ill. Worms not only rob your dog of valuable nutrients but they can also damage your dog’s internal organs and even be fatal. This is why it’s important to consult your veterinarian if you suspect your dog may have an infestation.

Signs & symptoms of worms in dogs

There are many signs of worms in dogs. Some are specific to certain species of worms, while other symptoms, like weight loss, anemia, malaise, and changes in appetite, are more general and can also be symptoms of many other diseases and conditions. Below is a comprehensive list of all the symptoms your dog might experience.

Symptoms of Worms in Dogs

  • Weight loss
  • Anemia
  • Diarrhea
  • Loss of appetite
  • Weakness
  • Pneumonia
  • Skin inflammation
  • Dermatitis
  • Blood in feces (fresh or tarry)
  • Inflamed rectum
  • Evidence of worms in feces or around rectum (tapeworms)
  • Evidence of worms in vomit or feces (roundworms)
  • Changes in coat condition
  • Malaise
  • Lack of growth (in puppies)
  • Loss of condition
  • Pot-bellied appearance
  • Coughing, lethargy (heartworms)
  • “Scooting”

Many puppies are born with worms, infected by their mothers transplacentally; others are infected shortly after, while nursing. This is why conscientious breeders follow a deworming schedule under the guidance of their veterinarians, and why puppy owners need to understand the signs. If your puppy is not growing, has a pot-bellied appearance, or is showing any of the other symptoms of worms in dogs, make an appointment with your veterinarian to see if worms—or something else—could be the culprit.

Worms can also affect adult dogs. Heartworms are particularly dangerous for dogs of all ages, and can be fatal if left untreated. Signs of heartworms in dogs include coughing, reduced activity, and malaise.

Intestinal worms can present with a range of symptoms, depending on the type of worm. Some worm larvae migrate through the skin (and other organs), which can cause dermatitis and skin inflammation. In large numbers, most worms can cause anemia as well as weakness, malaise, and changes in appetite and coat condition; weight loss is also common. Severe infestations can lead to other conditions, like pneumonia.

Finally, you may even see physical evidence of worms in your dog’s feces or around their rectum. Worms or worm segments may look like grains of rice or small pieces of spaghetti, but keep in mind they are not always visible.

Are worms in dogs contagious to other dogs

FAQ

Are worms in dogs contagious to other dogs?

Worms in dogs are contagious to other dogs, primarily through contact with infected stool and contaminated soil, though some types like tapeworms require more direct contact for transmission. It is generally recommended to treat all dogs in the household if one has worms, as these parasites are easily spread among pets.

Are parasites in dogs contagious?

Some parasites in dogs can be contagious, both to other dogs and to people. Intestinal worms can be particularly problematic, but some external parasites can be passed between dogs and people, too. Let’s look at some common canine parasites that can also pose health risks to dog owners.

Can dogs get worms?

While it is possible to get worms from pets, it is not very common. Worms cannot be transmitted from dogs to humans by licking. However, if a person comes into contact with dog feces that contains worm eggs, they can become infected with the worms. Additionally, people can become infected with roundworms by consuming contaminated food or water.

Is heartworm contagious between dogs?

Heartworm is not contagious between dogs. If your dog comes in contact with an infected dog, he will not become infected. However, if there is heartworm in your area, your dog may come in contact with a mosquito that transmits the disease.

How long do worms last in dogs?

A dog can have worms for months to years before it dies, depending on the severity of the infestation and the dog’s overall health, but untreated worm infestations can eventually lead to life-threatening complications. Are Worms Contagious To Other Dogs? Worms are highly contagious to other dogs and can be passed easily from one dog to another.

Can dogs get worms if left untreated?

If left untreated, roundworms can be fatal. Some types of worms can be transmitted from mother dogs to their puppies during pregnancy or nursing. Puppies can also become infected if they eat their mother’s feces. Fortunately, there are several things you can do to prevent your dog from getting worms.

How easily are worms passed from dog to dog?

This may involve transmission through feces and materials contaminated by feces like soil or sand, direct contact with worms or eggs, transmission from mother dogs to their babies, or transmission through an insect vector like fleas or mosquitos.

Do I need to treat my house if my dog has worms?

If your dog has been diagnosed with worms, quarantine is generally not necessary. However, you should take specific precautions to prevent the spread of the worms and protect your dog’s health: Veterinary Treatment: Consult your veterinarian for an appropriate deworming treatment.

Can my dog be around other dogs if he has worms?

No, your dog should not be around other dogs if it has worms, as many parasites are contagious through fecal-oral contact or environmental contamination.

Should dogs with worms be quarantined?

It’s important to keep your dog isolated from other pets and children in your home for a few days. Your veterinarian may suggest deworming other pets in the home as well to contain the spread. Be sure to pick up all their fecal matter immediately.