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Immune Support For Your Pets

Immune Support

Like us, our pets have an immune system. The immune system consists of the lymphatic system (lymph nodes, lymph vessels & tonsils), thymus, spleen, bone marrow, liver, intestines and white blood cells. These structures all help to defend the body and help it to fight off illnesses and infections caused by things it does not recognise and thinks could be dangerous e.g. viruses, parasites and bacteria.

Nutrition to support the immune system

With the immune system being such an important part of our pets health, it is important we look after it as best as we can. The phrase ‘you are what you eat’ comes to mind as most owners would agree that eating healthy food can help you stay in the best shape. It’s the same for our pets, healthy food without any chemical preservatives, colourings or artificial flavourings is a great start but getting the right balance of ingredients is also important. For example, it has been proven in both humans and animals that a deficiency in energy, protein, essential fatty acids and some minerals and vitamins can be detrimental to the immune system. On top of this, studies have shown that as our pets age there are changes to the immune system and they are more likely to develop tumours and infectious disease. However, it’s never too late to start supporting their immune system and alongside a healthy, balanced diet there are some ingredients/supplements that have shown promising results for immune health.  This article will explore some of the more important nutrients including:

  • Beta Glucans
  • Nucleotides
  • Antioxidants (Vitamins C & E)
  • Essential fatty acids
  • Amino acids
  • Prebiotics

Beta Glucans

Beta-Glucans are naturally occurring carbohydrate molecules found in the wall of Brewer’s Yeast; which is alsov an excellent source of B Vitamins and additional prebiotics.

Beta-1,3/1,6- glucans have been shown to reduce chemical messages that stimulate inflammation and increase the anti-inflammatory messages to white blood cells. These types of chemical changes are thought to be beneficial to the control of allergic skin disease in some dogs.


Nucleotides are the building blocks of DNA. DNA is present in every cell and provides genetic instructions for the cells’ function. Every time a cell divides it must replicate the strands of DNA for each new cell. The tissues in our body that produce new cells the most frequently are the cells that provide our natural defences, the gut wall and immune cells.

We naturally make nucleotides from the food we eat. However, in the cells that are dividing the quickest and most frequently (the gut and immune cells) it has been proven that by supplementing the building blocks (nucleotides) for cell replication when the defences are challenged, that the response is quicker and greater. Supplementing your dog’s food with nucleotides enables them to respond more quickly and efficiently to what life throws at them.


During normal cell metabolism the body produces unstable molecules called free radicals. These are responsible for normal ageing, but if they are able to increase in numbers they can cause disease and illness too. Contaminants such as pollution and damage from sunlight (sun burn) can increase the amount of free radicals the body produces. Due to their structure, immune cells are particularly vulnerable to damage from free radicals, however, antioxidants including Vitamins C and E help to neutralise free radicals and reduce the destruction caused by them. Vitamins C and E are found widely in foods, however plant oils and seeds are a rich source of Vitamin E and whilst citrus fruits are a well-known source of Vitamin C, but it is also it is found in other foods including green leafy veg such as kale and broccoli. Other rich sources of antioxidants include curcumin - the active ingredient in turmeric, grape seed extract (which is safe for dogs, unlike grapes) and spinach which contains the antioxidant lutein. Minerals including selenium, which contains an antioxidant enzyme and zinc also have very important roles in the immune system. The richest sources of zinc include meat, fish and nuts and selenium fish, meat and spinach.

Essential fatty acids

Fatty acids are ‘good’ fats that can be beneficial to health. In fact, some of them are vital for health and without them your pet would not survive. The essential ones cannot be produced by dogs or cats and must be obtained from their food. There are different types of Omega fatty acids, but the most well-known are Omega 6 Essential Fatty Acids (EFAs)  and Omega 3 EFAs.

The correct balance of Omega 6 to Omega 3 is important as an imbalance can actually produce inflammation; the amount and type of essential fatty acid can also affect the activity of immune cells. It is thought that there are other ways that EFAs help the immune system and current research is looking into this. 

Marine sources such as algae or fish oil are generally the best sources of Omega 3’s. Omega 6 fatty acids are found in plant and seed oils such as flaxseed, borage, sunflower and rapeseed but it is also smaller amounts in meat and cereals.

Amino acids and the immune system

Amino acids can be described as the building blocks of protein. Many amino acids are essential meaning that your dog or cat has to get them from their food. Three amino acids that have important roles in the immune system are arginine, cysteine and glutamine. Any complete dog food should contain all of these amino acids if it has a high enough meat content as they are mostly found in meat, fish, eggs and dairy. Arginine is also found in several types of nuts and glutamine in parsley and spinach.

Microbiome and prebiotics

Your dog’s diet affects the type and number of bacteria (and other microbes such as fungus) in their gut. This collection of microbes is known as the gut microbiome. Bacteria in the microbiome is essential for digestion and also affects the immune system. Some types of bacteria are seen as invaders and can trigger the immune system, whereas others are thought to be beneficial, this is an area of research which is of great interest and clinical studies are on-going. In dogs, the type and number of bacteria changes depending on whether the diet is high protein, low carbohydrate or vice versa. However, additional natural ingredients such as prebiotics or sources of prebiotics like inulin from chicory or Brewer’s yeast can also be important. Prebiotics help to feed the ‘good’ bacteria in the gut supporting overall gut health. 

Check with your vet

There are many foods that are thought to help support the immune system including citrus fruits (high in antioxidants), ginger, garlic and green tea extract. However, some of these are not suitable for pets. For example, green tea extract research has shown it has some very promising health benefits but if taken in high doses or on an empty stomach it can be lethal and garlic (and onions) can lead to anaemia if too much is eaten. Therefore, you might prefer to look for a complete food with added ingredients to maintain the immune system, or a vet recommended supplement so you can be sure the dose and ingredients are suitable for your pet.


Case, Daristotle, Hayek, Raasch (2001) , 3rd edn., Missouri: Mosby Elsevier. p 229-230.

Fascetti, A.J. & Delaney, S.J. (2012) , Chichester: Wiley Blackwell. p87

Dr. Callum Turner, DVM (2017) Available at:  (Accessed: 26th October 2017).

Sam Wang, Ph.D., and Sandra Aamodt, Ph.D. Play, Stress and the learning brain (2012)

Ornes, Stephen (2017) American Society for Microbiology: STUDY SHOWS HOW A DOG’S DIET SHAPES ITS GUT MICROBIOME

 Beetz et al (2012) Frontiers in Psychology: Psychosocial and Psychophysiological Effects of Human-Animal Interactions: The Possible Role of Oxytocin

How much should you give to your dog?

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