A cat and a dog snuggling in the grass

internal parasites in dogs and cats

Worms are little, but they can be a big health risk for your pet.

Heartworm, tapeworm, hookworm, whipworms, roundworm — learn about these nasty little internal parasites in dogs and cats.

Illustration of parasites

Common types of internal parasites

  • Heartworms
  • Hookworms
  • Tapeworms
  • Whipworms
  • Roundworms
Illustration of a dog food bowl

Signs of heartworms in pets

  • Reluctance to exercise
  • Decreased appetite
  • Swollen belly
  • Fatigue and couching
  • Sudden labored breathing
Illustration of a scale

Signs of intestinal worms in pets

  • Diarrhea
  • Weight loss
  • Increased or decreased appetite
  • Mucus or blood in stool
  • Dull, dry coat
Illustration of worms medication

Help prevent worms in dogs and cats

  • Regular heartworm preventive that includes protection against intestinal worms.
  • Administer medications and treatments as directed by your vet.
  • Remove feces promptly to avoid spreading the disease.
  • Consult your veterinary team.

Unwonderful worms

A French bulldog laying on its owner's legs

Heartworms = bad news

Heartworms are actual worms in your pet's heart. They’re transmitted by mosquito bites, affect pets in every state across the United States, and even a small infestation can cause long-term damage.

Signs and symptoms of heartworm disease

Early signs — schedule a veterinary checkup

  • Reluctance to exercise
  • Decreased appetite
  • Weight loss

Emergency — seek veterinary help immediately

  • Fatigue and coughing
  • Swollen belly
  • Sudden labored breathing
  • Pale gums from anemia and blood loss
  • Fainting

Find out more about heartworms in dogs and cats

Worms, worms, and more worms

Unfortunately, the worms don’t stop at heartworms. Tapeworms, hookworms, whipworms, roundworms — these nasty parasites all steal nutrients your BFF needs. Hookworms latch onto the small intestine and feed. Squirmy tapeworm bits and eggs sometimes appear under tails. Whipworms can cause no symptoms — and then quickly make pets really sick. Roundworms are common parasites in cats and dogs.  

While each of these worms present their own range of symptoms, common ones include diarrhea, weight loss, and changes in appetite. Young and/or compromised pets can also experience blood loss, anemia, and even death, so it’s important to talk to your veterinary team as soon as possible.

Safe and effective deworming treatments and prevention can help your pet stay tenant-free. Get the dirt on all worms

Parasite control goes beyond fleas and ticks

Parasite protection doesn’t just include fleas and ticks. Help keep your kittyBAE and doggyBFF happy and healthy with protection against internal worms. Contact your local Banfield to find the best option for your pet.

If your pet already has a worm problem, it’s important to follow your vet's instructions and administer all medications they've provided. Also, clean up your pet’s poop immediately to avoid spreading disease to others.

OWP

An Optimum Wellness Plan is a smart way to prevent pests

Our Optimum Wellness Plans® are affordable yearlong packages of essential preventive care. They're designed for different needs, ages, and lifestyles, and include options to easily add parasite control for fleas, ticks, and more.

Talk to your Banfield vet to find out which package is best for your pet.

Lean more about our packages

Mentioned in this article

A man and woman sitting together holding a cat and a dog

Does your dog or cat have worms?

All adult pets are at risk for worms.

Spot the signs

An old dog and a cat laying next to each other

Hookworm infection in pets

Hookworm can be life-threatening.

What to know

Illustration of a smartphone with chat bubbles

Worried about your pet? Ping Pet Chat!

Whether it's 3 a.m. or 3 p.m., connect with a real veterinary professional for immediate petcare advice. It's included in all Optimum Wellness Plans®!

Log in to start chatting
a cat and dog looking at a flea

Parasites on the prowl

20% OFF select parasite control meds or 25% OFF any new AutoShip. Use code BUZZOFF. Max $25 off. Terms apply.

Save at the Banfield Shop

Banfield can help prevent and treat parasites in pets

Regular wellness exams that include a full physical and fecal exam can help keep your furball happy and healthy. Kittens and puppies should start regular appointments when they’re about 6 weeks old, and then come in twice a year once they’re 5 months old. At your visits, we’ll check your little love from nose to tail, discuss age, needs, and lifestyle, and recommend trusted prevention medication to help fight off nasty critters that might feed on your pet.

A vet examining a small, scruffy dog while its owner holds the leash

Even if your pet is on a regular preventive for fleas, ticks, worms, mange, and other bugs, please make an appointment as soon as possible if you spot potential symptoms. Sooner is always better in helping to prevent a big infestation for your furry friend.

Back to top

You may also be interested in...

A person applying flea treatment to a cat's neck

Flea control for dogs and cats (and you)

Because fleas can make life miserable.

Control fleas now

A beagle itching/chewing on their hind leg

Signs of ringworm in dogs and cats

Ringworm isn’t a worm at all!

Spot the signs

A small dog laying on a sofa

Flea-borne diseases to avoid

Prevention is your best bet.

Spot the symptoms