Cryptosporidium in Dogs

Jenny Alonge, DVM
By Jenny Alonge, DVM on Mar. 28, 2024
A dog wades into water.

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In This Article


What Is Cryptosporidium in Dogs?

Cryptosporidium in dogs is a protozoan parasite that can infect pups as well as people. Infection with this parasite can cause acute, chronic, or intermittent diarrhea in infected dogs and people, a condition called cryptosporidiosis.

More than 40 cryptosporidium species have been identified, and the protozoan parasites are found worldwide. Most cryptosporidium species are highly adapted to a specific host type, but some can affect multiple animal species and humans. The species that most commonly infect people and dogs include Cryptosporidium hominis, C. parvum, and C. canis.

Studies performed by the Companion Animal Parasite Council (CAPC) indicate that cryptosporidium infection is common in dogs.

Infected dogs may or may not show symptoms, but they remain a source of environmental contamination—meaning they can still spread the infection.

Most infections that result in symptoms involve puppies younger than 6 months of age because their immune systems aren’t fully developed, which makes them susceptible to complications.

Cryptosporidiosis typically resolves without treatment in healthy dogs, but puppies and immunocompromised dogs may need medications and intravenous (IV) fluids to correct dehydration caused by diarrhea.

Diarrhea in puppies is always considered a veterinary emergency because puppies can quickly become dehydrated, which can be fatal.

Symptoms of Cryptosporidium in Dogs

When symptoms of cryptosporidium in dogs are present, they may include:

Causes of Cryptosporidium in Dogs

A dog can contract cryptosporidium by ingesting contaminated water, food, or feces.

Eggs containing infected cells—called sporozoites—are excreted through an infected host’s feces and possibly other routes, such as respiratory droplets.

Once infection occurs, the eggs hatch inside the body and go through several changes. After multiplying, each parasite develops into a male or female form.

These forms mate to produce eggs, which are released into the environment, where other animals and people can encounter the parasite.

How Veterinarians Diagnose Cryptosporidium in Dogs

Cryptosporidia are extremely tiny, which can make detection of cryptosporidium in dogs difficult. Exams and diagnostic tests your vet may use include:

  • History—Knowing if your dog was potentially exposed to a toxin or parasite can help your veterinarian diagnose your pup’s condition. In addition, inform your vet if you or any family members or other pets in the household are showing similar symptoms.

  • Physical exam—Your vet will perform a physical exam to determine if your dog has a fever or other abnormalities.

  • Blood work — Your veterinarian may recommend blood work, such as a complete blood count (CBC) and biochemistry profile, to evaluate your dog’s organ function and check for abnormalities in their white blood cell count, which can indicate an infection.

  • Fecal check—Testing can be done on your dog’s feces to determine if they have cryptosporidium, but these samples may have to be sent out to a laboratory, and you will likely have to wait several days for the results.

  • X-rays—In some cases, your veterinarian may recommend abdominal X-rays to rule out other conditions.

Treatment of Cryptosporidium in Dogs

Cryptosporidium in dogs typically requires no treatment if a pup is healthy.

For puppies and immunocompromised dogs, fluid therapy may be necessary to correct dehydration and electrolyte imbalances. In addition, medications such as azithromycin or paromomycin may be prescribed in persistent cases.

Recovery and Management of Cryptosporidium in Dogs

Symptoms of cryptosporidium in dogs typically resolve in less than two weeks in healthy dogs, and the prognosis is excellent. Puppies and immunocompromised dogs also typically have a good outcome if they receive appropriate treatment.

Limiting food or offering bland food while your dog is recovering can help their gastrointestinal (GI) tract heal quickly. Some dogs may also benefit when fiber or a probiotic is added to their diet.

Since cryptosporidium is potentially transmissible to humans, take care when handling your dog until your vet says they are no longer shedding eggs.

Wash your hands after handling your dog and their fecal matter, and only allow healthy adults to clean up after your dog, as children and immunocompromised individuals are at higher risk for infection.

Prevention of Cryptosporidium in Dogs

You never know where cryptosporidium may be lurking. Here are a few tips to help prevent cryptosporidium in dogs:

  • Take water and a portable water bowl with you on outings with your dog, so you can ensure the water they drink is clean.

  • Don’t let your dog drink from natural water sources or bowls left on the sidewalk by well-meaning vendors.

  • Keep your dog leashed and don’t allow them to come in contact with fecal matter.

  • Provide year-round parasite prevention. These products don’t prevent cryptosporidium, but they do protect against other parasites that can weaken your dog’s immune system and make them susceptible to cryptosporidiosis.

Jenny Alonge, DVM


Jenny Alonge, DVM


Dr. Jenny Alonge graduated from Mississippi State University College of Veterinary Medicine in 2002. She completed an equine medicine and...

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