Symptoms of Dog Worms
Symptoms of dog worms include worms in dog stool, diarrhea and vomiting. Read on and learn more about how to identify the different symptoms of worms in dogs.

Dogs are susceptible to several types of worms.

The most common types of worms in dogs are the four intestinal worms (roundworms, hookworms, tapeworms, whipworms), as well as heartworms that live in the dog’s heart.

So how can we tell if our dogs have worms? What are the common symptoms of worms in dogs?

By observing our dogs carefully, we can pick up some signs and symptoms of dog worms. Early detection and treatment of worm infestations can, in most cases, ensure full recovery.

Below is a list of some common signs and symptoms of worms in dogs.

General Symptoms of Dog Worms

Worms in Dog Stool

For intestinal worms, perhaps the most obvious sign is the presence of worms in your dog’s stool. So, it may be gross, but it is important to take a close look at your dog’s stool every time before you do your pooper-scooper duty.

Roundworms are the easiest to spot because whole worms can usually be seen in the feces. They are long, thick-bodied, whitish-to-cream-colored, and look like strands of spaghetti.

Tapeworm segments can sometimes be seen on dog stool or crawling through the hair near the dog’s anus. When dry, they look like grains of uncooked rice.

Hookworms and whipworms are difficult to spot because of their small sizes.

(Heartworms are not intestinal parasites so they are not passed in the dog’s stool.)

GI Problems

Except for heartworms, all other common types of dog worms live in the dog’s gut. So it is easy to imagine that one of the symptoms of dog worms is gastrointestinal problems.

For example, if your dog has intestinal worms, he will most likely show symptoms such as diarrhea and vomiting, which over time will lead to appetite loss and weight loss.

If your dog has diarrhea and/or vomiting on and off, and is beginning to lose his appetite and weight, be sure to have a fecal examination to see if he has worms.

Stunned Growth

One of the symptoms of dog worms in puppies is stunned growth and the inability to thrive. This is understandable since a large amount of nutrients are being taken away by the worms, leaving the puppies undernourished.


Dogs with worms are lethargic and weak, as they are not getting enough nutrition from their own body. They do not have the energy for various activities that healthy dogs enjoy, such as walking, running, and playing games.

Type-Specific Symptoms of Dog Worms

In addition to the above general symptoms of dog worms, different types of worms also cause specific symptoms in dogs.

Some specific symptoms of worms in dogs to look out for include:


Dogs, especially puppies, infested with hookworms are anemic because hookworms suck the blood of their host.

Signs of anemia include pale gums and mucous membranes, a pale or whitish tongue, weakness and lethargy. The dog may not have the energy to run fast, and may tire easily.

In severe cases, the dog will show symptoms of panting, rapid pulse, and fainting spells.

Blood in Stools

Puppies with hookworms pass bloody, tarry stools. Dogs with heavy whipworm infestation have colitis (inflammation of the intestinal wall) which causes the dogs to pass mucoid and bloody stools.


A dog with tapeworms sometimes scoots on the floor because fresh segments of the worms crawl around the dog’s anus. This causes extreme itching around the anus area. To relieve the itch, the dog may scoot on the floor.

Of course, a dog also scoots for other reasons, such as anal gland issues. In any case, if you see your dog scooting on the floor, be sure to take a look at his bottom to see if you can spot some worm segments.

A Pot Belly

Puppies with roundworms in their intestines usually have a pot belly. Another symptom of roundworms in puppies is that the puppies have a dull hair coat.

Coughing and Breathing Difficulty

Puppies with roundworms may also cough and have difficulty breathing. These symptoms are caused by the roundworm larvae in the puppy’s respiratory system.

In serious cases, pneumonia will result.

Dogs with mild to moderate heartworm infestations have a soft deep cough.

In cases of severe infestations, the infected dog will have difficulty breathing, panting, and have severe coughing after exercise to the point of fainting.

Congestive Heart Failure

Dogs with severe heartworm infestations also show signs of heart failure, such as the exercise intolerance, tiring easily, coughing, weight loss, and abdominal swelling.

To Sum Up

As you can see, there are lots of signs and symptoms of worms in dogs. Unfortunately, many of these signs are rather non-specific. Therefore, as the saying goes, “when in doubt, check it out!”

Some worms (e.g. whipworms, hookworms) can cause serious health damage to dogs, especially young puppies. So if your puppy or dog shows some of the signs described above, be sure to take the pup to the vet for a checkup.

For more information about the different types of worms and the treatment available, please visit the related pages below.

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