A dog’s immune system is like a shield against illness and other environmental toxins. Your dog is constantly exposed to household chemicals, allergens, and vector-carrying insects. All vertebrates, including dogs, have a complicated collection of defense responses to foreign microorganisms called an immune system.
According to Ian Tizard, Professor at College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, “There are three lines of defense against invaders: physical barriers, nonspecific (or innate) immunity, and specific (or adaptive) immunity.”
Dog’s physical barrier defenses include fur, skin, nails, and the urinary, digestive, reproductive, and respiratory tract. Physical barrier defenses also include fluids and bacteria that live on the barriers, such as saliva, tears, and digestive secretions.
Like humans, a dog’s nonspecific immunity is present at birth, called innate immunity. Nonspecific Immunity is the body’s inflammatory response. When inflammation occurs, white blood cells rush to the area invaded by foreign organisms, remove damaged cells, and kill the pathogens.
Specific immunity is a response that’s acquired, like vaccines. This response can single out the particular antigen (a substance that stimulates an immune response), such as rabies, and constructs the precise attack needed. Each antigen will require a specific design of defense to fend it off.
After the dog’s immune system has encountered the antigen once, it responds faster and more effectively than the previous encounter. Essentially, the immune system remembers how to attack and learns how to beat antigens more efficiently with each confrontation.
Both dog and human immune systems contain the same components: white blood cells, antibodies, bone marrow, and a thymus. However, the number of immune cells present differ from human to dog immune systems.
While it is difficult to measure if dogs have better immune systems than humans, it is safe to say that humans partake in more hygienic activities that increase their defense against pathogens.