What kennel cough, Giardia, flu and one particular patient taught us about the immune system
The same contamination, the same exposure, but completely different outcomes. Where is the difference?
NGD Care | Stefan Veenstra, DVM
On a playing field a dog with kennel cough walks. He coughs and plays on. With every cough, he spreads bacteria through small droplets in the air.
In the end, ten dogs play with him.
Within a few days, one dog ends up at the vet with serious complaints. Another dog also starts coughing a bit, but is free of complaints after three days. The rest of the dogs are not bothered by anything.
The same bacterium, the same time and the same exposure. Yet the results are completely different. Exactly the same pattern can be seen in parasites such as Giardia duodenalis, and even in humans during a flu epidemic, as recently reported by the RIVM.
The difference is in the immune system.
— NGD Care · Integrative Veterinary Medicine
How does that immune system actually work?
Most of the immune work is not done through the blood, but through the intestine.
The GALT controls protective substances that end up in the mucus of:
| → Intestines | → Airways |
| → Nose and throat | → Skin |
The main substances that the GALT controls, and what they do:
- sIgA: antibodies in the mucus that trap intruders before they can cause damage
- Lactoferrin: binds away iron, reducing the growth of harmful bacteria
- Calprotectin: an inflammatory protein that actively wards off invaders
- Defensins: small proteins that pierce the wall of bacteria
- Lysozyme: an enzyme that breaks down bacterial walls
- A healthy mucus layer: the physical barrier in which all this takes place
The microbiome plays an active role in this. Good bacteria occupy the space, produce protective substances themselves and give signals to the GALT to continue to control this defense.
If this system functions properly, intruders are removed before they can cause complaints.
What happens to the dog that does get sick?
In practice, we almost always see a combination of the following in these animals:
- A disturbed gut microbiome
- Low-grade (dormant) inflammation
- Chronic stress or overstimulation
- Reduced mucosal resistance
- Dysbiosis (disturbed bacterial balance) of the airways
- A reduced antiviral response (interferon, an antibody against viruses)
The bacterium enters, attaches to the mucous membrane wall and is given free rein.
Three cases, one pattern
Parasites, kennel cough and flu seem to be three different problems. Yet it always revolves around the same question: how much resistance does the mucous membrane offer?
Parasites enter many dogs. But they can only attach themselves if the intestinal mucosa is out of balance. In a healthy gut, parasites become:
- Retained by mucus and sIgA
- Inhibited by lactoferrin, calprotectin, defensins and lysozyme
- Supplanted by a healthy microbiome
And then disposed of, without causing an infection. Recurrent Giardia or other parasites are therefore rarely an exposure problem. It is a problem of mucous membrane defense.
Kennel cough is rarely the result of one causative agent. It is often caused by a combination of Bordetella bronchiseptica, the canine parainfluenza virus and canine adenovirus type 2.
These pathogens regularly enter the respiratory tract of dogs. Whether a dog actually gets sick depends on the same protective mucous membranes that are controlled by the GALT. An infection occurs when the anterior respiratory microbiome is out of balance, and pathogens can attach, multiply, and dominate.
Flu usually involves variants of the Influenza A and Influenza B virus. These viruses constantly change shape slightly (antigenic drift), making it difficult to target exactly the right variant with a vaccine.
Vaccines can reduce the severity of the symptoms, but can never completely take over the work of the mucous membrane defense. As with kennel cough, despite vaccination, we still regularly see symptoms of illness. Here too, the outcome depends very much on the state of the mucous membrane and the immune system.
TCM: why cold and wind viruses help
Within Traditional Chinese Medicine (TCM) this has been described for centuries:
- Cold slows down the blood flow to the mucous membranes
- Wind is the carrier of pathogens through the respiratory tract
- Less exercise and more sitting indoors weakens the intestinal blood flow
This weakens the first line of defense in the mucous membranes, right where viruses enter. We also know from Western medicine that viruses survive better in cold and humid conditions. Autumn and winter are therefore ideal conditions for flu epidemics.
Increasing resistance starts in the intestine
Case 4 · The intracellular bacterium
Sometimes, despite improvement in stool, appetite and microbiome, we still see insufficient recovery of energy and resistance. With a live blood analysis (darkfield microscopy) we look under the microscope at how active and loaded the blood cells are, in addition to regular blood tests.
We can then see:
- Intracellular bacteria and spirochete-like forms
- Overloaded neutrophils and monocytes (types of white blood cells)
- Yeasts and fungi in the plasma
- Poorly functioning red blood cells (erythrocytes)
- An overburdened liver and immune system
These are signs of an immune system that is continuously active and has little room for recovery. In practice, we often see that this is due to intracellular bacteria such as spirochetes, for example in Lyme or Erlichia infections. These cause a continuous burden on the immune system and maintain low-grade inflammation.
In such cases, we also focus on targeted support, for example with antibiotics, ozone therapy or antimicrobial essential oils such as Microbe Guard. We have also developed a new protocol for this.
Conclusion
Getting sick isn’t just about exposure. It’s about how much room the immune system has left.
Kennel cough, Giardia, parasites, flu, chronic inflammation, lethargy: these are not separate problems. They all tell the same story. The inside is out of balance.
A strong dog, or human, is not the one that is never exposed. It is the one whose system is balanced from within.
Do you want to know which protocol suits your dog or cat?
Scientific substantiation
- Dhar & Mohanty. Gut microbiota and respiratory health: the gut–lung axis. Frontiers in Microbiology.
- Budden et al. Emerging pathogenic links between microbiota and the gut–lung axis. Nature Reviews Microbiology.
- Honda & Littman. The microbiota in adaptive immune homeostasis. Nature.
- Function of mucosa-associated lymphoid tissue in antibody formation. Immunological Reviews.
- Marsland et al. The gut–lung axis in respiratory disease. Annals of the American Thoracic Society.
- Kogut et al. Mucosal immunity and IgA in respiratory defense in dogs. Veterinary Immunology and Immunopathology.
- Paules & Subbarao. Influenza. The Lancet.
- Moriyama et al. Seasonality of respiratory viral infections. Annual Review of Virology.
GALT
Microbiome
Kennel cough
Giardia
TCM
This text is intended as general information and does not replace individual veterinary advice. If in doubt, always contact your veterinarian.
NGD Care | Stefan Veenstra, DVM