Giardia & Pets

A girl hugging her pet dog

The risk of acquiring Giardia infection from your pet is small. However, there are some steps you can take to lower your risk.

Giardia intestinalis (aka: Giardia duodenalis, Giardia lamblia) is a common, microscopic (intestinal) parasite that commonly affects humans, dogs, and cats 1,2.

Common signs and symptoms of Giardia infection (in both humans and pets) are diarrhea, gas, abdominal discomfort, nausea, and vomiting. However, it is possible to be infected and have no signs or symptoms of illness 1,3,4.

Please visit our other web pages for a more detailed description of Giardia, including its life cycle, prevention tips, and treatment information for humans.

The risk of humans acquiring Giardia infection from dogs or cats is small 4-7. The exact type of Giardia that infects humans is usually not the same type that infects dogs and cats 5-7.

Note: If you own other household or exotic pets, please contact your veterinarian. Seek further information, as some rodents and other species can harbor human strains of Giardia.

Anything that comes into contact with feces (poop) from infected humans or animals can become contaminated with the Giardia parasite. People and animals become infected when they swallow the parasite. It is not possible to become infected through contact with blood.

Your dog or cat might get infected by:

  • Being in contact with infected feces (poop) from another dog or cat
  • Rolling and playing in contaminated soil
  • Licking its body after contact with a contaminated surface (for example, a dirty litter box or dog cage or crate)
  • Drinking water from a contaminated creek, pond, or other body of water

Young pets, like puppies and kittens, have a higher risk of illness than adult dogs and cats.

The risk of acquiring Giardia infection from your dog or cat is small. However, there are some steps you can take to minimize your exposure to Giardia if you have dogs or cats:

  • Wear gloves when gardening to reduce the risk of coming into contact with infected feces (poop) or soil.
  • Clean household surfaces regularly.
  • Clean and disinfect areas that your pet has access to—as well as items like toys, bedding, and water and food bowls—regularly.
  • Wash hands frequently and properly:
    • Wet your hands with clean, running water (warm or cold) and apply soap.
    • Rub your hands together to make a lather and scrub them well; be sure to scrub the backs of your hands, between your fingers, and under your nails.
    • Continue rubbing your hands for at least 20 seconds.
    • Rinse your hands well under running water.
    • Dry your hands using a clean towel or air dry them.

Giardia is hard to completely eliminate from the environment, but there are things you can do to decrease the risk of your pets’ reinfection and of human infection.

  • Hard surfaces (for example: cement and tile floors, crates, tables, trash cans, etc.)
    • Cleaning
      • Wear gloves.
      • Remove feces and discard in a plastic bag.
      • Clean and scrub surfaces using soap. Rinse surface thoroughly until no obvious visible contamination is present.
    • Disinfection
      • Wear gloves.
      • Disinfect according to manufacturer guidelines using one of the following:
        • Quaternary ammonium compound products (QATS) 4, which are found in some household cleaning products; the active ingredient may be listed as alkyl dimethyl ammonium chloride.
        • Bleach mixed with water (3/4 cup of bleach to 1 gallon of water) 8
      • Follow product instructions, ensuring the product stays in contact with the surface for the recommended amount of time.
      • Rinse with clean water.
  • Carpet / Upholstered Furniture
    • Cleaning
      • Wear gloves.
      • If feces are on a carpet or upholstered furniture, remove them with absorbent material (for example, double layered paper towels).
      • Place and discard the feces in a plastic bag.
      • Clean the contaminated area with regular detergent or carpet cleaning agent.
      • Allow carpet or upholstered furniture to fully dry.
    • Disinfection
      • Wear gloves.
      • Steam clean the area at 158°F for 5 minutes or 212°F for 1 minute.
      • Quaternary ammonium compound products (QATS) are found in some carpet cleaning products and can also be used after cleaning to disinfect. Read the product labels for specifications, and follow all instructions.
  • Other items (toys, clothing, pet bed, etc.)
    • Household items should be cleaned and disinfected daily while a dog or cat is being treated for Giardia infection.
    • Dishwasher
      • Dishwasher-safe toys and water and food bowls can be disinfected in a dishwasher that has a dry cycle or a final rinse that exceeds one of the following:
        • 113°F for 20 minutes
        • 122°F for 5 minutes
        • 162°F for 1 minute
        • If a dishwasher is not available, submerge dishwasher-safe items in boiling water for at least 1 minute (at elevations above 6,500 feet, boil for 3 minutes).
    • Washer and Dryer
      • Clothing, some pet items (for example, bedding and cloth toys) and linens (sheets and towels) can be washed in the washing machine and then heat-dried on the highest heat setting for 30 minutes.
      • If a clothes dryer is not available, allow clothes to thoroughly air dry under direct sunlight.

Giardia is hard to completely eliminate from the environment, but there are things you can do to help decrease the risk of pet reinfection and of human infection. Please remember that despite your best efforts to clean the environment, Giardia can persist in outdoor spaces and pet reinfection is possible 4.

  • Wear gloves when handling feces.
  • Remove feces promptly 4 and put them in a plastic bag.
  • Limit access to common outdoor spaces, where possible, if pets have diarrhea or are being treated for Giardia.
  • Eliminate any source of standing water (for example, puddles, containers with water, and fountains that are not in use).
  • Do not attempt to use bleach or QATS in your soil or grass area, as they will be ineffective.
  • Do not allow any new animals, especially young ones, to enter the yard or other outdoor space until advised by your veterinarian.

  • In the soil 8,9
    • In cold temperatures (around 4°C/39.2°F), Giardia can survive for approximately 7 weeks (49 days).
    • At room temperature (around 25°C/77°F), Giardia can survive for approximately 1 week (7 days).
  • Dry vs. moist surface or environment
    • In a dry, warm environment that experiences direct sunlight, Giardia can survive for only a few days 8,9.
    • In a moist, cool environment, Giardia can survive for up to several weeks.
  • Water 10
    • In water temperatures below 10°C/50°F (for example, lake water or puddle water during the winter, refrigerated water), Giardia can survive for 1–3 months.
    • In water temperatures above 10°C/50°F (for example, river water during the fall, tap water, and puddles during the summer), Giardia can survive for less time than in colder temperatures. For example, in water above 37°C/98.6°F, Giardia can survive less than 4 days.

  • Clean and disinfect potentially contaminated items (toys, water bowls and food bowls, pet bedding, floors, dog crates, linens, towels, litter box, etc.) regularly for as long as your pet is sick.
  • If your pet is taking medication, clean and disinfect frequently (daily if possible) until a few days after the last dose of medication is given.
  • Giardia survival depends on many factors, so we recommend that you consult your veterinarian for further advice.

  • If you have other dogs or cats, make sure you tell your veterinarian even if they are not showing signs of diarrhea. Other pets may also be put on medicine depending on the situation. Even animals showing no signs of Giardia infection could be infected and shedding Giardia into the environment 4.
  • Bathe all household pets with pet shampoo following medical treatment to ensure no fecal residue is in the pet’s coat 11.
  • Clean dogs’ and cats’ environment, as described above, 11 (holding areas, floors, crate, etc.) and wash water bowls daily with soap and water.
  • Limit your dog’s access to untreated surface water (creeks, ponds, lakes) to avoid re-infecting your animal and contaminating the water which could make other animals sick.

  • If your pet has persistent diarrhea, seek veterinary care. Diarrhea has different causes and could result in dehydration or other serious complications.
  • Diagnosis and treatment of Giardia infection must be done by a licensed veterinarian.
  • No approved over-the-counter treatment is available for Giardia infection.
  • Giardia can be passed in stool intermittently, and an animal may appear healthy or without signs of disease before it stops passing Giardia. Repeated fecal tests may be necessary 4.
  • Follow your veterinarian’s recommendations, and take your pet to all follow-up appointments.

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  2. Thompson, RCA. The zoonotic significance and molecular epidemiology of Giardia and giardiasis.External Vet Parasitol. 2004;126(1-2):15-35.
  3. Ballweber LR, Xiao L, Bowman D, Kahn G, Cama VA. Giardiasis in dogs and cats: update on epidemiology and public health significance.External Trends Parasitol. 2010;26(4):180-9.
  4. Tangtrongsup S, Scorza V. Update on the diagnosis and management of Giardia spp infections in dogs and cats. Cdc-pdf[PDF – 8 pages]External Top Companion Anim Med. 2010;25(3):155-62.
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  9. Olson ME, Goh J, Phillips M, Guselle N, McAllister TA. Giardia cyst and Cryptosporidium oocyst survival in water, soil, and cattle feces.External J Environ Qual. 1999;28(6):1991-1996.
  10. DeRegnier DP, Cole L, Schupp DG, Erlandsen SL. Viability of Giardia cysts suspended in lake, river, and tap water.External Appl Environ Microbiol. 1989;55(5):1223.
  11. Fletcher R, Deplazes P, Schnyder M. Control of Giardia infections with ronidazole and intensive hygiene management in a dog kennel.External Vet Parasitol. 2011;187(1-2):93-8.