My dog vomited worms. What should I do?

Estimated Reading Time 8 minutes
My dog vomited worms. What should I do?

Witnessing your dog vomiting worms can be a scary sight. Fear not, because you are in the same boat with many pet parents. Worm infestation is a common issue encountered by most pet owners at one time or another. Even if your pet has been dewormed, it will not guarantee 100% protection against reinfection. Understanding why your dog is throwing up worms and what you need to know about these creepy crawlies can help you take a proactive approach to protect your pet against infestation. Continue reading to learn more!

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Why did my dog vomit worms?

There are two main reasons why dogs may vomit worms:

1. A heavy intestinal parasite load can cause digestive upsets, leading to vomiting and diarrhea.

2. Worms can obstruct the gastrointestinal (GI) tract, which can cause vomiting and/or diarrhea.

If your dog vomited worms, there is a possibility that there is a heavy intestinal worm infestation. It’s highly recommended that you take your dog to your vet at the soonest possible time for proper diagnosis and treatment.

Symptoms of Intestinal Worm Infection in Dogs

The symptoms of intestinal parasites will vary depending on the type of worm, the worm load, the health status of the dog, and a variety of other factors. Common symptoms include:

  • Vomiting
  • Diarrhea
  • Lethargy
  • Potbellied appearance
  • Weight Loss
  • Dull hair coat
  • Coughing
  • Change in appetite
  • Stunted growth
  • Skin itching
  • Skin irritations
  • Scooting
  • Visible worms in the feces or vomit

Common Intestinal Worms That Affect Dogs


Roundworms are the most common types of parasitic worms living in dogs. The most common species of roundworms that affect dogs are Toxocara canis and Toxascaris leonina. Almost all dogs become infected with roundworms at one time or another. Infestation is highest in puppies because they can get the worms from their mother while they’re still in the womb and from their mother’s milk.

Other ways that dogs may be infected with roundworms include ingesting eggs from the environment and eating rodents, birds, and other animals that may have roundworms.

Adult roundworms dwell in the intestines of affected dogs. Many dogs don’t exhibit signs of infestation, however, it’s another story when puppies are carrying a heavy worm-load. There is diarrhea, vomiting, potbellied appearance, weight loss, and an unkempt dry hair coat. If the worms migrate through the puppy’s lungs, it can lead to coughing. There may be adult worms in the dog’s feces or vomit.

Considering that there are several ways by which a dog can acquire roundworms, it’s essential to keep a dog’s immediate environment clean. Feces should be removed regularly and disposed of properly. As much as possible, prevent your dog from eating prey animals that are known carriers of roundworms.

To get rid of roundworms in puppies, deworming should be done at 2, 4, 6, and 8 weeks old. A monthly preventive treatment can help protect dogs of all ages from roundworms.

An important concern associated with roundworm infestation in humans is the risk of transmission when eggs are ingested from contaminated soil or dog feces. Pregnant women and children are especially at risk of infection. Severe roundworm infection in humans can cause serious health issues affecting the eye, lung, heart, and nervous system.


Tapeworms are flatworms that live in the small intestine of dogs. They have sharp, hook-like mouths that enable them to latch onto the wall of the dog. The main route of transmission is the ingestion of an animal host or object that has tapeworm eggs. Fleas are the most common source of infection in dogs. Dogs get infected when they ingest infected fleas while scratching and grooming themselves.

The body of a tapeworm is divided into segments called ‘proglottids’, and each has its own reproductive organs. A segment detaches from the tapeworm’s body once the eggs inside mature. The segments look like rice or small white worms on the dog’s rear end, feces, or in places where your dog frequently stays or spends time in. Once the proglottid dries up in the environment, it breaks open and as many as 20 fertile tapeworm eggs are released into the environment.

The most common tapeworm in dogs is Dipylidium caninum. This species is commonly transmitted by fleas. Other species of tapeworms include Taenia and Echinococcus with small rodents, rabbits, sheep, deer, and other mammals as intermediate hosts.

A heavy tapeworm infestation tends to be more serious in puppies than in adult dogs. Affected puppies may have stunted growth and anemia. A large number of worms may block the intestinal passage which can be dangerous because digested food is unable to pass. There may also be diarrhea, abdominal pain, and unexplained weight loss.

Dipylidium caninum cannot be transmitted to humans, as the parasite depends on fleas as intermediate hosts. There are, however, a few cases of tapeworm infection in children and adults which are attributed to swallowing of infected fleas.

If tapeworm segments are present on your dog’s rear end and/or feces, or you notice frequent scooting, you should have your pet checked by a vet. Medication can be administered orally or by injection. Flea control is critical in protecting your pet against tapeworm infection.


Hookworms are very small and can hardly be seen by the naked eye. They have very sharp teeth that help them attach to the dog’s intestinal wall. They feed on the blood of their hosts and release an anticoagulant into the sites where they are attached. This causes continuous bleeding even after they have stopped feeding and become detached. Heavy infestations can lead to severe anemia, bloody diarrhea, and weight loss.

Adult hookworms that live in the small intestines lay eggs that are passed out in the feces. The eggs hatch in the environment and can infect dogs by direct contact and penetration of the skin. The dog could also ingest dirt that contains the hookworm larvae when they lick themselves after a romp in the yard.

The larvae of the hookworm, Ancylostoma caninum, can be transmitted to puppies when they feed on the milk of an infected mother. Heavy hookworm infestations can be fatal in young puppies. Blood transfusion is often needed for their survival. In adult dogs, the most distinct symptoms are diarrhea and unexplained weight loss.

Maintaining hygiene and sanitation in your dog’s surroundings is of optimum importance. Puppies have a very high rate of hookworm infection, and deworming is necessary at 2, 4, 6, and 8 weeks for adequate protection. Consult your vet for a safe and effective worming medication for your pet.

Humans can be infected by some species of dog hookworms. The hookworm larvae can penetrate the skin when walking barefoot in places where pets may defecate. Symptoms include itching at the point of the larvae’s entry and visible skin tracks. Depending on the number of larvae that are present, the affected person can suffer from mild to extreme discomfort.

What can you expect after deworming your dog?

There are not many visible signs that can be exhibited after you deworm your dog. There may be some mild vomiting, diarrhea, and your pet may not show much interest in his food. This may occur for a few days as the body gets rid of the worms.

If there are adult worms in the intestines, the medication will kill them and they will eventually be expelled with the feces. In some cases, the expelled worms may still be in the process of dying and you may see them crawling around. You won’t see any parasite eggs as they are not visible to the naked eye.

There are, however, a few serious side effects to certain dewormers but these cases are very rare. You should contact your vet or take your pet to the veterinary hospital if you notice any of the following symptoms:

  • Blood on your dog’s stool
  • Diarrhea that lasts longer than three days
  • Loss of appetite for more than 1-2 days
  • Vomits more than once
  • Trembling
  • Extreme lethargy
  • Breathing difficulties
  • Incoordination

How to Prevent Intestinal Worms in Dogs

Dogs are such curious creatures and their love for exploring their environment with their mouth increases their exposure to worm eggs and infective larvae. The good news is, there are several ways to protect your pet against worm infestation. These include:

1. Work closely with your vet in creating a health preventive program that will include regular deworming. Make sure to follow the instructions of your vet regarding the frequency of deworming. Giving the proper dosage can help reduce the possibility of adverse side effects. If your dog has intestinal worms, your vet will prescribe the appropriate worming medication.

2. Take your dog to your vet for regular health and wellness checks. Even if your dog appears active and healthy, these visits are important opportunities to spot potential health issues early so they can be addressed immediately. A stool exam (fecal analysis) is one of the basic laboratory procedures that are often performed during wellness checks.

3. Maintaining hygiene and sanitation in your dog’s immediate environment is very important. This involves picking up dog feces as soon as possible and proper disposal. Wash your hands each time you handle pets, raw meat, or pick up dog poop, as worms can transfer to humans, too. If you have sandboxes in your yard, cover them to prevent wildlife from having any access and possibly contaminating the environment. Dog feces should be placed in sealable bags and properly disposed of.

4. When going on outdoor excursions with your dog, keep him away from the feces of other animals, as well as rodents and other potential intermediate hosts of intestinal parasites.

Read more:

Parasites That Cause Diarrhea in Dogs

Common Skin Parasites in Dogs

What to Do if Your Dog is Vomiting

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Published: 10/1/2021
Last updated: 10/5/2021

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