How Do I Know If My Dog Has Worms?

Dogs with worms often show symptoms such as weight loss, lack of energy or appetite, dull coat, visible worms or eggs in their feces, coughing, diarrhea, or bloating. However, some dogs may not display any noticeable symptoms despite being heavily infested. The best way to know if your dog has worms is to get routine fecal check-ups from a vet.

Another reliable method is to do regular fecal float examinations. It’s a simple test where the vet mixes a small feces sample with a special solution. The solution makes the eggs float for easy viewing under a microscope. In case your dog has worms, the vet can recommend appropriate medication treatment.

Remember that a healthy diet and good hygiene can prevent worm infestations. Always aim to keep your dog free from exposure to infected feces, contaminated soil or fleas, which are common sources of worms.

Last Updated on September 20, 2023

The idea that our dogs have worms is horrible. We give them the best dog foods, keep their vaccines up to date, choose the best flea shampoo out there; they still get worms. Unfortunately, worms in the environment (apart from our house) are completely out of our control. What we can do, however, is look early on for signs of worms in our dogs. Which leads us to the question: What are the signs of worms in dogs? 

shih tzu

Worms in dogs

There are 5 types of worms that affect your dog. They are tapeworms, roundworms, hookworms, whipworms, and heartworms. Heartworms may be harder to diagnose as infected dogs only show little to none symptoms of infection. Some worms, on the other hand, maybe easier to spot. If you see small grains of rice on your dog’s stool, then you’ll know for sure he has worms. It can either be tapeworms or roundworms.

It’s important to bear in mind, however, that one type of worm can have identical symptoms as another. This is why a fecal test should be performed to correctly diagnose your dog and consequently give the right treatment. As a summary, below are the key points you need to know for each type of worms.


In the U.S., Dipylidium caninum is the most common type of tapeworm that affects dogs. It’s an intestinal parasite that attaches to the intestinal lining of your dog. Dogs commonly get this parasite when he ingests an infected flea – another reason to add to the list on why you should take tick and flea prevention seriously.  


Roundworms are the most common intestinal worms in dogs and can be transmitted to humans. There are two types of roundworms that affect dogs: Toxocara canis (T. canis) and Toxascaris leoninaT. canis. But you will most likely find roundworm infections in puppies as they can be passed down from their mothers. This is the reason why newborn puppies must get veterinary care. Apart from preventing Parvovirus, roundworms can be avoided as well.

Another rare type of roundworm that affects dogs is the raccoon roundworm called Baylisascaris procyonis (B.procyonis). This parasite is native in North America and is known to spread to humans. It can be acquired through ingestion of infectious eggs or ingesting infected hosts such as rodents, rabbits, and birds. Because these worms can be passed on to humans, they must be treated ASAP.  


Hookworms are small intestinal parasites that attach to your dog’s intestinal wall. Although small in size (about 1/8 of an inch), hookworms are fatal parasites to your dog. They ingest large amounts of blood that can cause anemia when left unchecked. Many types of hookworms can affect dogs. One particular type, Ancylostoma caninum, is passed through the dam’s milk to her puppies.

Additionally, any dog who consumes larvae from the environment can get infected with the parasite. An infected dog can pass hundreds of microscopic eggs in their stool, where they hatch and live in the soil for several months. A dog who steps on a contaminated surface and lick its paws can get the parasite. A dog who also sniffs infected feces is also in danger of infection. Humans can be infected by hookworms.

labrador retriever


Whipworms are worms that live at the beginning of the large intestine and colon of our dogs. In mild cases, whipworms will not cause any symptoms. But for severe cases, inflammation, diarrhea, weight loss, and anemia are seen. Where do dogs get them? Dogs get this parasite from ingesting any contaminated substance. This includes soil, food, water, feces, or animal flesh.

The eggs can survive for up to 5 years in a warm and moist condition. For this reason, pet owners are required to clean after their pet not just for sanitary purposes but for health reasons as well. Furthermore, whipworm eggs are difficult to find. When testing for whipworms, it’s common to get false negatives. Thus, repeated fecal exams are needed.


Heartworms are the most dangerous type of worm that is spread through mosquito bites. What makes them alarming is that until the larvae mature and multiply inside the dog’s heart, the dog will not show any symptoms. But by the time signs of illnesses are seen, the condition is already severe. Apart from that, heartworms can only be detected through blood testing. Hence, in the case of heartworms, prevention is better than treatment.

While it’s difficult to suppress mosquitoes in most places, regular heartworm prevention will keep your dog safe.

You may also be interested in: Can You Get Ringworm From A Dog? 

dog in the sand

How to know if your dog has worms?

You will know your dog has any of the worms mentioned above if he is experiencing any of these symptoms: 

  • Coughing. Coughing can be a sign of heartworms, hookworms, or roundworms. According to Cesar’s Way, dogs with heartworms will have a dry and persistent cough after exercising. This is most likely an early sign of heartworms. However, dogs with roundworms can also have coughs. As for dogs with hookworms, coughing will only be for severe cases.
  • Vomiting. All types of worms can cause vomiting. To know for sure if it’s worms causing them, look for worms in his vomit.
  • Diarrhea. Soft stools and diarrhea are an indicator of worms. Dogs who are suffering from hookworms, in particular, can have bloody stools. It’s also especially risky for dogs who have heartworms. Blood loss can result in lethargy, high blood pressure, and even heart failure.
  • Bloated appearance. A pot-bellied appearance is a common symptom, especially for dogs with roundworms.
  • Low energy. Not being able to absorb nutrients and blood loss can cause your dog to feel weak.
  • Weight loss. A rapid weight loss can be a sign of tapeworm or whipworm.
  • Change in appetite. A change in appetite can either be a loss of appetite or a sudden increase in hunger. This symptom is common for dogs with roundworms.
  • Dull coat. A healthy dog has a shiny, thick coat. But for dogs who have worms, a dull and dry coat is inevitable. He may also experience hair loss and rashes.
  • Extreme itching.
  • Scooting. Scooting is when he drags his bottom on the ground. It’s a typical indication of tapeworm infection. This also includes excessive chewing or biting on his rear. This is an attempt to relieve him of his itch due to the worms.
  • Visible worms on his stool or his fur. Worms on his stool can look like grains of rice or hard yellow specks when dry. You may also find this on your dog’s anus or around his bottom.  

If you suspect that your dog has worms, contact your veterinarian immediately.

Also related: How Do I Firm Up My Dog’s Stool? 


Any dog can get worms. Even if he is up to date with his vaccines, he can still contract the parasites. But to catch these parasites early, dog owners should know the telltale signs of infection. Some of the signs are coughing, vomiting, diarrhea, bloated appearance, lethargy, rapid weight loss, change in appetite, dull coat, itching, scooting, and worms in his stool.

If you think he has worms, don’t panic. Most worms are easy to treat. Your veterinarian will prescribe him medication for a few weeks, and he’ll be back to his energetic self before you know it.  

Related Posts

Scroll to Top