How to tell if your dog has worms and the most effective way to treat it

This article was medically reviewed by Sorin McKnight, DVM, a veterinarian at Wellborn Road Veterinary Medical Center in College Station, Texas.

worms in dog poop

If you suspect your dog has worms, make sure you check your dog's poop for worm fragments or eggs.
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  • If your dog has worms, you may find small grain-like worms in their poop.
  • Tiny worm eggs may also be present in your dog's poop, but these are usually harder to spot.
  • You may also notice behavioral changes in your dog, like scooting and a decreased appetite.
  • Visit Insider's Health Reference library for more advice.

Intestinal worms, also known as intestinal parasites, are a common problem for dogs and dog parents. They can come from a variety of sources and wreak havoc on your dog's gastrointestinal tract. And if worms are not treated, more serious clinical issues can arise.

However, it's not always easy to tell if your dog has worms, which is why it's so important to stay on top of your pet's health. Here are some key signs that may indicate your dog has worms and how to treat and prevent them in the future.

Signs that your dog has worms

Some key signs that your dog may have worms — especially if it's a large worm load — include:

  • Diarrhea or soft stool
  • Vomiting
  • Weight loss
  • Blood in the stool
  • Visible worms in feces or vomit
  • Distended abdomen

In some cases, you might notice behavioral changes in your dog, says Travis Arndt, DVM, director of Animal Medical Center of Mid-America. These may include:

  • Frequent licking or irritation around their bottom
  • Scooting
  • Loss of appetite

Even if your dog is exhibiting these signs, it can still be hard to know if they have worms or another gastrointestinal condition. In addition to watching out for signs, you should also check for worms in your dog's stool.

In fact, "most intestinal parasites are actually identified in a fecal sample by visualization of the parasite eggs in the stool, not visualization of the actual worm," says Mandese adding that if you suspect worms, take a stool sample to your vet for diagnosis.

How do dogs get worms?

There are four main types of intestinal worms in North America, says Mandese. They are:

  • Hookworms
  • Roundworms
  • Tapeworms
  • Whipworms

Dogs can get worms from a few different sources:

  • Eating worm eggs: Mandese says most intestinal parasites are spread if a dog eats the worm eggs that are found in the feces or vomit of infected animals. This can occur if your dog directly eats the feces or if they ingest contaminated grass, plants, or water.
  • Eating fleas: Tapeworms, in particular, are spread if your dog ingests fleas infected by tapeworm larvae. This often happens when your dog has infected fleas and then grooms himself by licking his fur. Be sure to give your dog a flea preventative to reduce the risk of this.
  • Passed from the mother: They can also be passed from mother to puppy during birth, says Ann Hohenhaus, DACVIM, staff doctor at New York City's Animal Medical Center. This is why it's so crucial for the mother to have great prenatal care, and to be dewormed with medication if necessary.

How do you treat a dog with worms?

 If your dog does happen to get worms, it is treatable. There are different medications available to deworm your dogs.

Some deworming medications are given to the dog for three to five days while other drugs only require one dosage. Hohenhaus says once the dog starts medication, they should see results in a few days.

It's important that you treat your dog for worms as soon as possible. If you allow a worm infestation to be untreated for too long, the worms can multiply and cause serious complications such as anemia caused by hookworms, intestinal blockages caused by roundworms or severe diarrhea caused by whipworms.

Prevention of worms

You can take preventative measures to make sure your dog doesn't get worms.

  • Monthly heartworm medication: You likely give your dog heartworm medication every month already, and this medication also contains compounds that are specific to intestinal worms, as well, says Hohenhaus.
  • Flea preventative: Since tapeworms almost always spread through fleas, make sure you give your dog a veterinarian-approved flea preventative year-round, says Arndt.
  • Keep your dog away from contaminated areas: To prevent hookworm and roundworm infections, Arndt says pet parents can prevent their dogs from playing in soil that could be contaminated by feces and keeping them away from infected rodents.

Insider's takeaway

Worms can certainly be a pesky problem for both the dog and the owner to deal with, but they are preventable and treatable. If you notice any signs that your dog may be ill or if you see worms in your dog's vomit or stool, it's crucial that you take them to the vet ASAP to get them taken care of.

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Ashley Laderer is a freelance writer from New York who specializes in health and wellness. Follow her on Twitter @ashladerer

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