These cells, when functioning properly, are extremely effective in filtering the blood. Clumps of lymphoid tissue are found in many other parts of the body, especially in the linings of the digestive tract and the airways and lungs that serve as gateways to the body. These tissues include the tonsils, the adenoids, and the appendix. Obviously, a broad range of nutrients are required for immune function. There are many books, review articles and primary research papers that discuss the relationship between nutrition and the immune system.
Wholesome nutrition is a key component of maintaining a healthy immune system.
You're probably tired of hearing me say this but a raw diet is unsurpassed in providing the best nutrition for both dogs and cats. Proper digestion is a requirement for optimum health, and incomplete or disordered digestion can be a major contributor to the development of many diseases. The problem is not only that ingestion of foods and nutritional substances are of little benefit when breakdown and assimilation are inadequate, but also that incompletely digested food molecules can be inappropriately absorbed into the blood stream. This can lead to various diseases and the development of food allergies. The basic premise of natural rearing is to provide an animal with the best chance of having an immune system that functions at an optimal level.