In the small intestine, the giardia parasite can form a biofilm around itself. Think of what happens when a bowl of water is left standing for too long; a layer of slime forms on it. The green layer in a vase of flowers that is left standing for too long is also a good example. Such a layer of slime is called a biofilm and protects the parasites against antibiotics and other medication.

Whether or not the giardia has nested in a biofilm is very difficult to prove, but if the giardia does not disappear despite various regular treatments, this could certainly be a cause. As long as that biofilm is not broken down first, the parasite is perfectly hidden there and you cannot get rid of it!

A little further along in the intestinal tract, in the large intestine, the parasite also forms a protective layer around itself, but now to be able to transform into a cyst. In this form, the giardia is excreted with the feces. The cyst can survive for months outside the host, especially in a wet environment in mild weather. As a result, we will probably never get rid of giardia and infections are unfortunately lurking everywhere.

Dogs become infected when they ingest cysts found in contaminated water, food, or feces from infected animals.

Although many dogs show no symptoms, some infected dogs may develop diarrhea, weight loss, decreased appetite, itching, behavioral problems, and poor overall health. Often, diarrhea is the only symptom that is focused on, but diarrhea is not always present; Giardia can also be present in normal, hard stools. When diarrhea is present, the frequency can vary.
So the dog does not have to have diarrhea all the time. The diarrhea can also smell very bad and look green. Sometimes mucus or blood is also seen.

In addition, there may also be other symptoms, such as behavioral problems, itching, sudden lack of cleanliness, poor appetite, lethargy, reduced concentration, being inaccessible, difficulty getting some rest, easily frustrated and/or increased sensitivity to stimuli. And let's not forget the puppies that are very busy and/or show hyper and biting behavior!

Why one dog develops visible symptoms and another does not depends mainly on the condition of the intestinal health, age (giardia is most commonly seen in dogs under 1 year old) and the living environment.

As described, the giardia parasite attaches itself to the intestinal wall with a kind of suction cup. This causes damage to the intestinal wall and makes the intestinal wall too permeable.

The intestinal wall consists of many very small protrusions. These are called villi. The purpose of these bulges is to increase intestinal surface area so that more nutrients can be absorbed.

These intestinal villi, in turn, consist of different intestinal cells, each with different functions. In healthy intestines, these intestinal cells are tightly packed together, forming a kind of security barrier.

That barrier contains channels through which nutrients are selectively allowed to pass. One is allowed to pass and the other is restrained and not allowed to pass. We call the connections between these cells the tight junctions. It goes wrong when these intestinal wall cells become damaged, causing the tight junctions to open more and the intestinal wall cells become inflamed. This is also what happens with giardia.

Substances that were previously prevented by this barrier can now pass through because there is more space. For example, think of pathogenic bacteria, yeasts, molds, but also nutrients that have not yet been digested. We call this a leaky gut.

When this happens the immune system kicks in to destroy these passed-on particles. The liver is also heavily taxed. This reaction of the immune system can cause the dog to suddenly react violently to certain foods and develop an allergic reaction when these foods were never an issue before. This can even become an allergic reaction to airborne particles. Because this is continuous and only temporary, the immune system cannot keep up with it and these particles eventually cause inflammation in other parts of the body, for example in the skin, but also ongoing gastrointestinal symptoms and even behavioral problems. So the immune system continuously remains overactive and also becomes exhausted which can lead to autoimmune diseases in the long run.

Giardia, in addition to making the intestinal wall permeable, also has the narrow property to alter the good bacteria in the intestines. They also affect the intestinal villi causing them to shorten and there is a problem with food absorption, we also call this malabsorption.

Giardia is obviously not just a parasite, it can really cause a lot of misery. As a result, intestinal problems can still occur long after the giardia parasites have disappeared. For example, consider allergies, gut dysbiosis, or other intestinal diseases. It is therefore extremely important in the case of a giardia infection to not only focus on eliminating the parasites, but also to pay attention to restoring gut health. In practice, this step is often overlooked. But all these problems don’t fix themselves.

Also, with behavioral issues, gut health, and certainly giardia, needs to be considered. Behavior and gut go hand in hand. Between the gut and the brain runs a kind of telephone wire we call the vagus nerve, aka the gut-brain axis. This axis has a number of functions: - regulate digestion - regulate appetite - regulating emotions and moods - regulating the immune system

The vagus nerve is the means of communication between the brain and the gut. 80% of this communication even goes from the gut TO the brain. Therefore, the gut is also called the 2nd brain. Besides the intestines and brain, the vagus nerve also affects other organs such as the liver, kidneys, heart, lungs, spleen, pancreas and even branches to the ears and throat.

The vagus nerve is also part of the autonomic nervous system and plays an important role in regulating the stress system in the body. When the brain receives a signal of stress from the gut, this can cause decreased appetite or the excessive biting behavior we do see in pups, but can also activate a dog’s fight-flight system and emotions are affected causing us to fear or aggression may be seen in the behavior.
So you can imagine that when the intestines are out of balance due to inflammation or leaky gut, for example, it has a negative impact on communication to the brain and thus will also affect the dog’s behaviour. It can even cause inflammation in the brain!

Once there is an absorption problem, long-term deficiencies in vitamins and minerals will occur. This too causes stress in the intestines and organs as it affects their functioning. We then get into the same chain reaction, where the deficiencies can cause behavioral problems via the gut-brain axis.

So, in young pups and adolescents with behavioral problems, it may also certainly make sense to rule out whether giardia plays a role in this.

On a regular basis, the treatment for giardia is actually always opted for panacur (fenbendazole) or antibiotics (usually metrobactin). Unfortunately, practice shows that these agents are not always equally effective and research has also shown that more research is needed into the efficacy of these agents in giardia. Only 17% of the dogs in this study had complete elimination of the parasite after treatment with 5 days of fenbendazole.

After this, further treatment often stops and no work is done to restore gut health. Sometimes probiotics are prescribed, but it is very important that the right strains are used at the right time. If you are going to put a random probiotic in a leaky gut, these bacteria will also leak into the bloodstream and that is not what we want! The probiotics can then also have a negative effect. Probiotics are no good it does not then it does not harm resource!

From a complementary point of view, there are various supplements and homeopathic remedies that can be used in eliminating giardia. Unfortunately, this is unknown to many. As a therapist, we look very broadly and work with supportive resources without addressing additional harm.
So the diet is monitored to limit the intake of carbohydrates and minimize the stress on the intestines, the parasite is obviously addressed, but also looking at supporting the immune system and the liver.
Once the giardia is gone, it’s not over right away. One then needs to work on intestinal health and restoring the intestinal wall so that resistance can increase again.

It is not meaningful to name the possibilities because here too it is true that this does not help it does not harm it is not means. Owners should always do this approach under the guidance of an orthomolecular, integrative nutritional therapist or a homeopath.

As a dog owner, you can choose which path you want to take, there are several roads that lead to Rome, also in the treatment of giardia.

Testing is important!

Preventive testing, or at least moving to testing sooner than is commonly done now is also recommended. Research published in February 2024 found that giardia is more common in dogs under 12 months than in dogs older than 12 months, but also that changes in stool were not always observed. From the study: “It can be concluded that periodic surveillance of apparently healthy dogs and cats is necessary to rule out G. duodenalis infection.”

The sooner giardia is detected, the better damage to gut health can be prevented. However, a dog with good gut health and a good immune system does not have to suffer from giardia, but that does not mean that the parasite does not cause harm. Why wait to intervene until there are symptoms, until the dog actually gets sick? If pups and toddlers up to 12 months of age were tested monthly or every 2 months, for example, action could be taken much more quickly when a test is positive.

Because giardia is shed intermittently (so not with every stool) it is important to test with several different stools, but also with some regularity.

Owners can do this at home, (veterinarians are not burdened) by collecting 3 days of stool and testing with, for example, the Fassisi rapid test. This test detects both cyst protein and trophozoites and has a very high sensitivity. Because giardia cysts are not excreted in every stool, it is important to collect 3-day stools to minimize the risk of a false-negative result.

Using a test that tests for both cyst protein and trophozoites minimizes the chance of a false-positive result. It is also noted that tests can remain positive for a long time because the cysts are excreted for a long time. However, more research is needed as there is still insufficient information.

Obviously careful consideration should be given to what is treated in the absence of symptoms, because when a dog has no symptoms, treatment with panacur or antibiotics is very intrusive and may well do more damage than the giardia itself at that point (this is still but briefly present). And of course that’s not the intention.

As said, there are other options in terms of treatment and these would certainly pay off at this stage. Again, these are also still no good it does not harm remedies, but under the guidance of an orthomolecular, integrative nutrition therapist or a homeopath can determine which remedies can be used and in what dosage. This can ensure that no additional damage is done to the gut health but works supportively.

With these methods, a lot of misery in our dogs may be prevented by simply intervening sooner.