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    PeterDobias.com / Blog / health knowledge

    Natural guide to Giardia treatment and prevention in dogs

    By Dr. Peter Dobias, DVM

    Dr. Peter Dobias, DVM has 30 years of experience as a veterinarian. His love of dogs and passion for natural healing and nutrition led him to writing, teaching and helping people create health naturally, without drugs, chemicals and processed food.

    How bad is Giardia for your dog?

    I have no idea what put Giardia into my head today, maybe the fact that my little wild creature Pax is drinking from puddles, creeks, and rivers. However, despite his “humanly unacceptable indiscretions,” he almost never gets diarrhea, and if he does, all it takes is a pile of drugs to get him better!

    I trust you know that I am joking!😉

    In fact, all I would have to do is to take him through a couple of days of my diarrhea protocol, which I have found works reliably well in 98 out of 100 dogs. 

    What is Giardia?

    It is a tiny flagellate, a microorganism equipped with a little tail that propels it around. The word flagellate is very appropriate considering that they wave their “flag” to move from place to place.  

    There are two forms of Giardia:

    1. The cyst, which can be seen as a little capsule the species survives within, in the inhospitable environment outside of the bowel.

    2. The trophozoite (the mature stage) is more fragile but it is the one that causes small bowel diarrhea and digestion difficulties in dogs, humans, and other animals.
    Diagram of a Giardia cyst
    Giardia under a microscope

    This may prompt you to ask the following question:

    Can Giardia be transferred from dogs to humans, and vice versa?

    The most recent research suggests that transfer of Giardia between humans and dogs is not very common, which is great news. This means if your dog enjoys drinking from creeks and puddles, or going into the bushes and eating….ehrmm, you know what, you are likely still safe.

    How bad is Giardia for dogs?

    Similar to many other intestinal pathogens, Giardia is an opportunist, meaning that it will start multiplying and causing problems in a compromised gut that is unhealthy, inflamed, weakened or leaky.

    In fact, Giardia can be found in about 1/3 of all dogs that are healthy and symptom free.

    What makes your dog’s gut more susceptible?

    The number one predisposing factor is kibble and processed food in general. Such food usually sits on shelves for months or years and becomes rancid before it is fed to dogs. Almost all dogs fed processed food suffer some form of gut inflammation, or have weakened intestinal flora, which makes them predisposed to Giardia.

    Food preservatives are designed to prevent bacterial decay of food, but they also have a negative effect on the microbiome.

    Dogs with an inflamed or injured lumbar spine are also predisposed to a weaker gut and diarrhea, including Giardia infections. (Click here for more details)

    What happens when Giardia settles in the gut in high numbers?

    First, let me emphasize that finding Giardia in a dog that has no symptoms of diarrhea is common and DOESN’T require treatment.  

    But if Giardia settles in a weaker gut and multiplies in high numbers, it will flatten the intestinal villi, the very fine mesh-like structures of the gut lining that are responsible for nutrient absorption. This can lead to diarrhea, altered nutrient absorption, electrolyte loss, and dehydration.

    How is Giardia diagnosed?

    The easiest way to diagnose the parasite is via a so-called “flotation test” which uses zinc sulphate. The solution makes the trophozoites float to the surface of the test tube, and the top layer is then examined under a microscope.  

    However, the parasite is often missed or mistaken for other “artifacts” such as pollen or other material.  

    Plus, as I mentioned before, the presence of Giardia doesn’t necessarily mean that there is a symptom-inducing infection.

    Another test that can be done is an immunofluorescence assay, which is good at detecting hidden dormant forms of the pathogen.

    There is another test called “wet mount” which is a fancy term for “testing by mixing poop in water” similar to when kids play "cooks” on a playground.

    Mix, shake, and pop the poop
    under a microscope!


    doesn’t mean a disease.

    doesn’t rule out disease.

      Will antibiotics and anti-parasitic medication eliminate Giardia?

      The general consensus is that drugs used for the treatment of Giardia do not eliminate the parasite, and often cause counterproductive side-effects.

      For example, metronidazole, is still the most commonly used drug used to treat diarrhea and Giardia, despite the fact that it causes side-effects such as diarrhea, decreased immune function, and long term disturbances of the intestinal microbiome. For more details click here.

      If you are wondering why such a treatment is used, I can only guess it is because metronidazole manufacturers said so, and no one questioned their recommendation.

      Fenbendazole, an anti-parasitic drug, is currently used more often, however this drug has a negative effect on the liver, can cause gastrointestinal symptoms such as diarrhea, and can also cause bone marrow suppression.

      I often see dogs being put on 2 or 3 courses of antibiotics, without them having any symptoms, with the unreasonable goal of eliminating the parasite. Many of these efforts fail and cause more damage when using very potent yet not very effective drugs such as metronidazole or fenbendazole.

      I REPEAT: 
      Antibiotics usually do not eliminate the parasite.
      A healthy gut and immune system keeps Giardia in check


      Here is what I recommend:

      If your dog has been diagnosed with Giardia and
      has no symptoms,
      do not treat with antibiotics, and optimize their diet based on
      the recommendations below.

      If your dog has been diagnosed with Giardia and
      has symptoms,
      do not treat with antibiotics initially, unless there
      is no improvement. Optimize their diet based on
      the recommendations below, and
      use medication as a very last resort!

      If your dog has no symptom, no giardiasis, and you want to prevent it,
      it is still important to optimize your dog's diet and use canine specific probiotics and FeelGood Omega.


      If there are no symptoms, annual Giardia screening is NOT needed!


        Conventional treatment often DOESN’T eliminate Giardia, and the body is capable of controlling the parasite if we focus on improving gut health.

        STEP 1

        Switch to a raw or cooked diet
        This means that
        your dog should not eat anything that it would not eat in the wild.

        Any processed corn, wheat, or other grain, processed food, or food that is chemically preserved, will compromise the gut.

        Even if a particular dog food is made of species appropriate ingredients but is processed, baked, or dehydrated it may cause sufficient strain on the digestive tract allowing diarrhea to occur.

        I know processed food is convenient, I know it is sometimes less costly, but
        not switching to a natural raw or home-cooked diet is like someone complaining they are getting flat tires when the garage floor is covered with nails.

        STEP 2

        What to feed if your dog has diarrhea

        • Fast for 24-48 hours (dogs can easily fast for 7 days, so do not worry about doing this).
        • Introduce puree (comprised of low fat meat broth and cooked squash or pumpkin) for the first two meals, then switch back to their regular cooked or raw diet.

        Note: Do not feed rice despite it being commonly recommended for dogs with diarrhea, here is why:

        High starch diets affect the microbiome, as increasing carbohydrate content increases the chances of Giardia proliferation.

        Rice contains a high amount of arsenic due to the fact that it is often grown in industrially polluted waters in Asia.

        STEP 3

        Giardia supplement protocol for your dog

        1. Add FeelGood Omega - a sustainable Omega-3 oil that is the key to reducing inflammation and powering the enterocytes (the intestinal lining cells).

        2. Add GutSense - a dog-specific prebiotic, probiotic, and digestive support. Initially, give a double dose for the first 4 weeks if your dog has chronic problems.

        Note: Studies have shown that asymptomatic Giardia carriers have a different microbiome from dogs that are symptomatic, which means that a healthy microbiome is important to prevent clinical disease.

        3. Add cinnamon - (ground) in your dog’s food - 150 mg/kg daily for 2 weeks or longer, if necessary. It can be given all in one meal, or divided between meals if you feed more than once per day. Research shows that cinnamon reduces the number of Giardia cysts.*

        4. Add ginger - (dry or fresh) into your dog’s food. 1/8 tsp for small dogs, 1/4 tsp for medium dogs and 1/2 tsp for large dogs. Ginger reduces the number of Giardia trophozoites.*  

        The above supplement protocol supports regeneration of the intestinal lining, reduces inflammation, and improves immune function of the gut and body.

        The primary goal of treatment is to stop clinical signs of giardiasis.

        The elimination of Giardia is not the primary goal of either conventional or holistic therapy, as about 1/3 of dogs carry Giardia and do not have any symptoms. Giardia is not a concern for most dogs that have a healthy gut, which should be your focus.

        Click here to hear an audio version of this blog post. 



        *Ginger and Cinnamon: Can This Household Remedy Treat Giardiasis? Parasitological and Histopathological Studies (2014)

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        Dr. Peter Dobias, DVM has 30 years of experience as a veterinarian. He graduated as a Doctor of Veterinary Medicine in 1988 in the Czech Republic and obtained the Canadian Certificate of Qualification in 1995. He is currently licensed in the European Union, and his unique approach to healing and nutrition helps holistically minded dog lovers worldwide.

        Dr. Dobias strongly believes that disease prevention, natural nutrition and supplements, the right exercise and a drug free approach to medicine can add years to your dog's life.

        As a formulator of his all-natural vitamin and supplement line and co-inventor of natural, chemical free flea and tick control, FleaHex® and TickHex®, his unique healing system and products currently hold the highest independent five star customer rating. For more information click here.

        Any general recommendations that Dr. Dobias makes are not a substitute for the appropriate veterinary care and are for informational and educational purposes only.

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