We all know how important diet and nutrition are in maintaining good health, for both ourselves and our pets. This is why it is important to provide our animals with a varied diet, to ensure that they receive all the nutrients they need and to prevent deficiencies.
Whilst we may feed certain foodstuffs to correct or prevent deficiency, an increasing number of ‘bioactive’ ingredients can be found in a variety of pet foods. These ingredients are added to actively improve or maintain certain aspects of animal health. For example; prebiotics and probiotics that can act as digestive aids, or antioxidants that can aid brain function.
A recent study investigated the role of certain dietary components on feline immunity. It has been shown that the addition of certain ingredients to the diet can enhance immunity in rats and humans, so the study looked at whether the same was true for cats. We consider the metabolism of the cat to be specialised (due to its carnivorous diet), so it isn’t possible to simply assume that what is true for us is true for cats.
The Role of the Feline Immune System
The feline immune system functions much like our own; a complex relationship between cells, tissues, organs and disease-causing pathogens protects the cat from disease.
Whilst there are a number of ways the feline immune system can deal with bacteria, parasites and other foreign invaders, the most commonly recognised defence mechanism is the white blood cell. White blood cells, or leukocytes, roam the body and respond to sites of infection or inflammation. Different types of leukocytes have different specialities and thus different roles.
The study discussed in this article showed that adding specific ingredients to a cat’s diet improved the phagocytic function of white blood cells – this is the ability of certain cells to ‘consume’ foreign particles such as bacteria. A process that is very important in immunity.
Ingredients Believed to Improve Feline Immunity
The study looked at three specific ingredients, all of which are believed to have a role in improving immunity:
- Arginine – An essential amino acid for cats, it is required to produce enzymes that break down protein after a meal. Arginine has been shown to stimulate the the human and rodent immune system.
- Nucleotides – A small sugar molecule that is the building block of DNA. Nucleotides have been shown to be effective in enhancing the human immune function of newborn babies. Nucleotide-free diets have been shown to increase susceptibility to infection.
- EPA & DHA – These omega-3 essential fatty acids are believed to decrease the risk of heart disease. Whilst some research suggest these omega-3 fatty acids can improve immune function, there is also conflicting research that suggests supplementation with omega 3 fatty acids can cause immune suppression.
Rutherfurd-Markwick Study Investigates Ingredients that May Improve Feline Immunity
The Rutherfurd-Markwick study consisted of five groups of cats, each group was fed a different diet. After a period of 35 days, numerous tests were conducted to determine whether the immune system had been enhanced as a result of the diet.
The five diets were:
- High protein (control diet)
- Low protein (control diet)
- Low protein + arginine
- Low protein + salmon oil (omega-3 essential fatty acids)
- Low protein + nucleotides (derived from yeast)
Conclusion of the Rutherfurd-Markwick Study on Improving Feline Immunity via the Diet
The study found that after only 14 days of being fed a non-control diet (low protein diet + arginine, salmon oil or nucleotides), there was a significant improvement in phagocytic function compared to the control (high/low protein) diets. This means that leukocytes (white blood cells) had an improved ability to consume and destroy foriegn particles such as bacteria.
The conclusion of the study was that it is possible to improve feline immunity by adding specific ingredients to the diet. Arginine, omega-3 essential fatty acids and nucleotides all improved the cat’s ability to deal with infection-causing agents such as bacteria. It is also worth noting that all the animals involved in the study remained healthy and no significant change in body weight was observed.
The ‘immune strength’ of the leukocytes was tested by mixing fluorescent E. coli with blood. Analysing the results allowed the researches to determine the activity of the leukocytes.