Most dog parents think about their dogs’ immune systems when their dogs are puppies and seniors. While these are critical times of the system’s development and decline, the system needs support throughout your dog’s life. Let’s take a closer look at the canine immune system and how you can keep it healthy.

How does the immune system work?

A dog’s immune system is a complex network of cells and organs that protect the body from foreign antigens, like toxins, bacteria, infections, and viruses. It’s not located in one specific place in the body. In fact, there are immune system cells and organs all throughout the body, in the blood, bone marrow, lymph nodes, thymus gland, liver, spleen and intestines. When the immune system detects an antigen, it triggers an immune response. This involves producing T-lymphocytes, a type of white blood cell also known as T-cells, protective proteins called antibodies, and other immune cells to attack and destroy the invading antigen.

What happens to the immune system as dogs grow older?

T-cells are produced in bone marrow and then mature and multiply in the thymus gland. Once they’ve matured, they enter the bloodstream where they await activation by immune response. As dogs (and humans) age, their thymus deteriorates. The biggest decline is seen between ages 1 – 5. With this deterioration comes a gradual deterioration of the dog’s overall immune function, which causes a reduced response to invading antigens.1 The result is that dogs become more susceptible to infections and diseases as they age.

How can I keep my dog’s immune system healthy?

Keep your dog up to date on their vaccinations.

Vaccines protect dogs from serious diseases like rabies, distemper, parvovirus, distemper, canine influenza, hepatitis, and more. Work with your veterinarian to ensure that your dog receives the vaccinations they need at the correct times, typically every one to three years.

Feed a healthy, well-balanced diet with nutrients known to support a strong immune system.

These include:

  • PROTEIN – Proteins are made of amino acids, which play a key role in the immune system. Conversely, a deficiency in protein can weaken the immune system. Dogs should be fed diets with high levels of high-quality protein, like real chicken or fish.
  • OMEGA-3 FATTY ACIDS – Omega-3 fatty acids EPA and DHA promote immune system health. Cold water fatty fish, like salmon, is an excellent source of omega-3s.
  • ANTIOXIDANTS – Antioxidants, particularly Vitamins A, C, E and B-Carotene, help protect against free radical damage, and overall strengthen dogs’ immune systems.
  • MINERALS – Dogs require specific minerals in their diet, many of which support immune function. These include zinc, selenium, and magnesium.
  • PROBIOTICS & PREBIOTICS – Probiotics enhance the immune system by adding beneficial bacteria and decreasing harmful bacteria in the gut while stimulating immune antibodies, particularly in elderly dogs.2 Prebiotics feed probiotics and fuel healthy bacterial growth. Probiotics and prebiotics are increasingly found in commercial dog food diets as more and more dog parents are understanding the many benefits they provide.

Did you know?
Almost 70% of your dog’s immune system is found in their gut.3

Consider Functional Treats & Supplements

In addition to their regular meals, you can add beneficial immunity-boosting nutrients with functional treats and supplements. Dogswell Immune System Treats give dogs as much as 60% protein, omega-3s, and powerful antioxidants in four different forms – soft & chewy, jerky, mini jerky, and tenders. Other helpful supplements include:

  • SALMON OIL – A rich source of omega-3 fatty acids, salmon oil is easy to add to their regular kibble. Dogswell Wild Alaskan Salmon Oil is made with sustainably sourced wild-caught salmon, which contains higher omega-3 levels than farmed salmon oil.
  • BOVINE COLOSTRUM – Studies have shown that feeding dogs bovine colostrum benefits the immune cells in the gut and causes them to have stronger responses to vaccines.4 Dogswell Immune System Soft & Chewy Treats include 25mg/piece of bovine colostrum, plus protein from real duck, vitamins A and E, flaxseed and turmeric.

Keep your dog fit and active.

Regular exercise helps burn fat and keeps immune systems functioning properly. Make time each day to help your dog get the exercise they need. Take them for a walk, run, or hike, and play with them. It not only keeps their bodies healthy; it promotes bonding and improves their mental health as well.


1 Holder, A. et. al. (2016) An Age-Associated Decline in Thymic Output Differs in Dog Breeds According to their Longevity. National Library of Medicine.

2 Haiyan Xu. et. al. (2019) Oral Administration of Compound Probiotics Improved Canine Feed Intake, Weight Gain, Immunity and Intestinal Microbiota. National Library of Medicine.

3 Vighi, G. et al. (2008). Allergy and the gastrointestinal system. Clinical and Experimental Immunology, 153 (S1) 3–6.

4 Satyaraj, E. et al (2013). Supplementation of diets with bovine colostrum influences immune function in dogs. British Journal of Nutrition, 110(12), 2216–2221.

1 thought on “Dogs’ Immune Systems: Protecting Them From Within”

  1. What an informative read! Protecting our dogs from within is key to their overall well-being. Understanding the importance of a strong immune system is crucial for every responsible pet owner. Thanks for shedding light on this vital topic!

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