Giardia in Dogs: What Every Dog Owner Should Know

Giardia is one of the most common intestinal parasites found in dogs. It can affect dogs of any age but is especially common in puppies and dogs that visit parks, daycare, boarding facilities, hiking trails, or areas where many dogs frequent.

The good news? Giardia is treatable, and there are several ways you can reduce your dog's risk.

What Is Giardia?
Giardia is a microscopic protozoan parasite that lives in the small intestine. Unlike worms, you won't see Giardia in your dog's stool.  It damages the lining of the intestines, making it difficult for dogs to properly absorb nutrients and water.

How Do Dogs Get Giardia?
Dogs become infected by swallowing Giardia cysts.
Common sources include:

• Drinking contaminated puddles, streams, or standing water
• Licking contaminated grass or soil
• Eating contaminated feces
• Walking through infected feces and licking their paws
• Shared water bowls
• Contaminated kennels or outdoor play areas
• Contact with infected dogs

Because Giardia cysts survive well in moist environments, they're especially common during wet weather.

Signs of Giardia
Some infected dogs show no symptoms at all while still spreading the parasite.
Others may develop:

• Soft stool
• Watery diarrhea
• Greasy or foul-smelling stool (it's a very noticeable smell)
  
• Mucus in the stool
• Weight loss
• Poor coat quality
• Dehydration
  
• Occasional vomiting
• Reduced appetite

Many dogs continue acting completely normal despite having diarrhea.

How Veterinarians Test for Giardia
Diagnosis usually involves: 

• Fecal Antigen (ELISA) Test:  The most common and most accurate in-clinic screening test. 
  
• Microscopic Fecal Examination: Looks for Giardia cysts under a microscope.
• Fecal PCR Testing: Some veterinary laboratories perform PCR testing for additional confirmation.

Because Giardia isn't shed consistently, your veterinarian may recommend multiple fecal samples if results are negative but symptoms continue.

How Is Giardia Treated?
Treatment typically includes:

• Prescription antiparasitic medication (commonly fenbendazole or metronidazole)
• Bathing your dog during treatment to remove cysts from the coat
• Cleaning bedding and toys
• Frequent disinfecting of food and water bowls
• Picking up feces immediately
• Follow-up fecal testing if recommended by your veterinarian

Many dogs recover quickly with treatment.

Can People Catch Giardia?
Some Giardia species can infect humans, although the strains dogs carry are often different than those affecting people.  Good hygiene greatly reduces the risk:

• Wash hands after handling stool.
• Pick up feces immediately.
• Wash food and water bowls regularly.
• Avoid letting dogs drink from standing water.

How The Blue Hound Helps Protect Your Dog
Preventing contagious illnesses starts long before dogs begin playing together.

At The Blue Hound, we take multiple steps to reduce disease risk:
✔ Veterinary-grade disinfectants approved for animal care facilities
✔ Daily cleaning and sanitation of play areas, grooming equipment, bowls, toys, and common surfaces
✔ Review of vaccination and medical history before new clients begin services
✔ Wellness questionnaires before boarding and grooming visits
✔ Dogs showing signs of illness are asked to reschedule until healthy
✔ We actively monitor reports of contagious illnesses occurring locally and at surrounding pet care facilities. If a dog has recently visited a location experiencing an outbreak, we may recommend postponing their visit to help protect every guest in our care.

While no daycare, boarding, grooming salon, dog park, or veterinary clinic can guarantee zero exposure to contagious disease, layered prevention dramatically reduces risk.

When Should You Call Your Veterinarian?
Contact your veterinarian if your dog has:

• Diarrhea lasting longer than 24 hours
• Bloody stool
• Vomiting with diarrhea
• Lethargy
  
• Refusal to eat
• Weight loss
• Signs of dehydration
• A puppy with diarrhea (which should always be evaluated promptly)

Early treatment helps your dog recover faster and reduces the chance of spreading Giardia to other pets.

Sources

• Companion Animal Parasite Council (CAPC) Giardia Guidelines
• American Veterinary Medical Association (AVMA)
• Merck Veterinary Manual
• Cornell University College of Veterinary Medicine
• Washington State University College of Veterinary Medicine