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Dog Parasites That Are Common in Colorado

January 30th, 2018 by Cherished Companions Animal Clinic

A blue heeler dog plays in a mountain lake.

What to know about giardia, roundworms, coccidia and tapeworms

Living in Castle Rock, Colorado, we don’t see as many cases of dog parasites as in other parts of the country.

Still, it’s definitely possible for your dog to get intestinal parasites here.

Our veterinarians typically see two cases of dog parasites per week.

What kinds of dogs are more likely to get intestinal parasites in Colorado, you ask?

  • Puppies
  • Dogs that hunt and ingest small animals
  • Dogs that play in or drink from streams, ponds or standing water
  • Dogs that visit dog parks or areas with a lot of animal traffic

Here are the key things you should know about dog parasites in Colorado, so you can help keep your dog — and your family — healthy!

What are dog parasites?

Dog parasites are unwanted critters that work their way into your dog’s intestinal tract and suck nutrients from your dog.

In many cases, intestinal parasites are types of worms.

Sometimes, they’re so tiny you can’t see them with the naked eye. We can only see them with a microscope.

A microscopic view of giardia cysts, roundworm ova and coccidia. Copyright Cherished Companions Animal Clinic.

Recently we performed an intestinal parasite screen that had a trifecta of results. The blue arrows indicate giardia cysts. The red arrow indicates roundworm ova. And the green arrows represent a species called coccidia. The good news is all of these parasites are treatable!

What are the most common dog parasites in Colorado?

The most common dog parasites our Castle Rock veterinarians see are:

  • Giardia
  • Roundworms (particularly in puppies)
  • Coccidia (particularly in puppies)
  • Tapeworms


Giardia is a microscopic parasite that lives in your dog’s intestines.

How do dogs get giardia?

Your dog can get giardia from:

  • Drinking a contaminated water source (like a stream or a pond)
  • Ingesting an animal that has giardia
  • Eating infected feces

You may notice your dog has diarrhea, vomiting or weight loss.

If your dog has diarrhea, we’ll always recommend you bring in a stool sample, so we can check for giardia and other parasites.

Dog giardia doesn’t offer a high risk of contamination for people, but it can be unpleasant for your dog.

It also can be one of the more difficult parasites to treat.

Jack rests by a river with his dog, Charlie. Charlie once got dog parasites from drinking an infected stream.


It’s common for puppies to get roundworms from their mothers in utero or while they’re nursing.

Your puppy picks up the larvae, and the larvae develop into worms in your pup’s intestines.

Sometimes, roundworms can be seen in your dog’s stool or vomit. The adult worms look like spaghetti.

Typically, they’re round, white in color, and three or more inches in length.

But other times, you can’t see an clinical symptoms – especially for mild to moderate cases of roundworms.

We need to run a fecal test to identify them.

(Our vets look for the worms’ microscopic eggs. The adult worms pass hundreds of eggs daily.)

One of the most concerning types of roundworm – “toxicara” – can be transmitted to people.

Children tend to be at higher risk, so we watch for that one when we look for parasites in your dog.

Sadie, a pug-chihuahua mix, sits and waits for the results of her intestinal parasite screen.


Coccidia are single-cell parasites that live in dogs’ intestines.

They’re most common in young puppies, particularly pups under stress.

This parasite inflames and irritates your dog’s intestine, causing a watery diarrhea. Your dog can get coccidia through direct contact with other animals or their feces.

The good news is coccidia can be treated effectively with medication.

Plus, the dog form of coccidia is not transferable to humans.


Tapeworms usually live in your dog’s small intestines.

These parasites are long, flat and ribbon-like. They’re sometimes several feet in length, and they’re made up of many smaller segments.

These small, rice-like segments can sometimes be seen around your dog’s anal area.

Typically, dogs get tapeworms from ingesting fleas.

However, here in Colorado, your dog is more likely to get tapeworms from eating an infected animal (such as a rodent or a rabbit carcass).

Tapeworms cannot be directly transmitted to humans from your dog or your dog’s feces.

How do you get rid of intestinal parasites in dogs?

It’s a great question.

Quite simply, the treatment varies by parasite.

There are different “deworming” medications for different types of worms.

Some dog parasites (like roundworm) are relatively quick to get rid of. Others (like giardia) can be more stubborn.

If we diagnose your dog with intestinal parasites, our veterinarians will walk you through all the steps to take for that parasite — including ways to keep your human family members safe.

Find out how to prevent dog parasites here.

 Wondering whether your dog has parasites?

Get the peace of mind you need! Simply bring your dog’s most recent stool sample into our veterinary clinic. (No appointment needed.)

We’ll run a fecal test and call you with the results and any recommendations.

Have questions? Call us at 303-688-3757.

Cherished Companions Animal Clinic is a veterinary clinic in Castle Rock, Colorado. Specializing in the care of cats and dogs, our goal is to help you and your pet feel more comfortable, keeping your stress to a minimum.

This article is intended to provide general guidance on dog parasites in Colorado. If you have specific questions or concerns, please contact your local veterinarian. (If you live in or around Castle Rock, we welcome your call: 303-688-3757.)

© 2018, Cherished Companions Animal Clinic

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