Giardia in dogs

Giardia in dogs can be challenging to treat, but it’s usually not a life-threatening disease. Younger dogs are more likely to be infected with this parasite. 

Giardia is a tiny parasite that causes upset tummies. It carries a low risk of spreading to humans, but it’s recommended to practise good hand and house hygiene when handling your dog with giardiasis.



What is giardia in dogs?

  • Giardia is a one-celled parasite, not a worm, bacteria, or virus.
  • This parasite sticks to its host’s guts to feed itself.
  • It can infect dogs and cause watery diarrhoea.
  • Humans and other animals (such as cats) can catch giardia.
  • Giardiasis is the name of the disease caused by the parasite giardia.

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How do dogs get giardiasis?

Your dog can catch giardia by:

  • Being in contact with infected poo from another animal.
  • Rolling and playing in contaminated soil and grass.
  • Licking their own fur and body after contact with a contaminated surface.
  • Drinking water from a contaminated creek, pond, or others.



Symptoms of giardia in dogs

Symptoms of giardiasis normally begin 1 to 2 weeks after becoming infected.

These include:

  • Strong smelling, watery diarrhoea
  • Diarrhoea sometimes containing mucous
  • Farting (flatulence)
  • Eating less
  • Vomiting



Are some dogs more likely to show giardia symptoms?

Younger dogs or those with weakened immune systems are more likely to experience symptoms of giardia infection.



How is giardia in dogs diagnosed?

To diagnose giardia, your vet will need to examine a stool sample.

Because giardia can be shed intermittently in the stool, it might not be seen on a single stool sample. So your vets may request that you collect samples for 3 to 5 days.

Your vet may perform a second stool test, such as Giardia-specific antigens, to help detect specific proteins from the parasite.

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How to collect a poo sample

  • Usually, your vet provides you with a poo sample container that comes with a spoon attached to it.
  • Or you may use a clean container, like tupperware or a poobag.
  • When possible, wear gloves when touching the stool. If not, wash your hands thoroughly immediately afterwards.
  • Collect around two scoops of poo, close it, and label it with your pet’s details.
  • The samples need to be stored in the fridge.
  • But to avoid any food contamination, put the sample into another bigger container before you place it in the fridge.
  • Repeat this process for another 2 or 4 days, as requested by your vet.
  • You may store the stools in different containers each day, or you may place them all in the same container.
  • When the collection is all completed, take it to your vet practice.

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Vet treatment

What’s the treatment for giardia in dogs?

Giardia can be difficult to kill. The goal of treatment is to resolve the diarrhoea and other signs that your dog may have.

Your vets will discuss treatment with you and will include environmental management instructions. See the next section for more information.


  • Fenbendazole is a common deworming medication used to treat giardia.
  • Metronidazole is an antibiotic that is also used as a treatment option.
  • Your vets may use the two medications in combination.


  • Your vet may prescribe a diet that supports digestive health to help resolve diarrhoea.
  • Such as Hill’s Prescription Diet i/d.
  • They may also add a probiotic.

It typically takes at least a couple of weeks of treatment and strict environmental management to clear the disease.


Home treatment

What you need to do at home to treat your dog with giardia

Environmental and hygiene management of your home and pets is very important not only to treat this disease but also to prevent re-infection. Take the following actions:


  • Common household disinfectants are the most effective ways to kill giardia.
  • Clean your house regularly.
  • Remove and dispose of all poo without delay.
  • Giardia on the lawn can only be killed by direct sunlight drying them.
  • To kill giardia on a concrete surface, perform basic cleaning before disinfecting.


  • Dogs should be fully bathed regularly, or at least on the last day of treatment, to remove any residual poo and any remaining giardia from their fur.



How to prevent and control giardia in dogs

Preventing and controlling giardiasis can be a difficult task. Giardia can persist on animals fur and in the environment for months, even after the original poo has gone.

Some steps can help decrease, but not eliminate, the risk of reinfection to your dog or transmission to other animals:

  • Do not miss any doses of the medication given by your vets.
  • Clean the floor in your home daily.
  • Regularly clean any potentially contaminated items, such as toys, water and food bowls, pet bedding, dog crates, and upholstery.
  • Regularly clean any outdoor surfaces.
  • Continue cleaning until a few days after the last dose of medication is given.
  • Limit your dog’s access to creeks, ponds, and lakes to avoid re-infecting themselves and also contaminating the water, which could make other animals sick.

Can your dog pass giardia on to your family?

The chances of people getting a giardia infection from dogs or cats are low. The type of giardia that infects humans is not usually the same type that infects dogs and cats.

However, maintenance of good hygiene practices, such as regular hand-washing is important.


When to worry

When to worry about your dog with giardia

Seek help from a vet practice if your dog:

  • Has vomiting and diarrhoea and is looking unwell
  • Looks bloated
  • Is still vomiting despite your vet’s treatment
  • Their poo is covered in blood or has specks of blood for more than one day
  • Is in pain

Joii can help if:

  • Your dog is well but not interested in food or water
  • You want to discuss feeding
  • Your dog has one poo with specks of blood
  • You need help with hygiene management


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