The ability of the body to resist infection from disease-causing microorganisms or pathogens, damage from foreign substances and harmful chemicals is known as

immunity / immune system

Explanation:

Immune system, system, of the Latin systema, is an ordered module of interrelated elements that interact with each other. It can be real objects or abstract concepts that are endowed with organization. It is the body's natural defense against infections, such as bacteria and viruses. Through a well-organized reaction, the body attacks and destroys the infectious organisms that invade it. These foreign bodies are called antigens. In people who are in good health, the immune system can distinguish between the body's own tissues and the strangers that invade it, such as viruses and bacteria.

It is formed by the set of biological structures and processes that protect the organism by identifying and destroying pathogenic cells, viruses, parasites. The immune system, therefore, must appeal to various mechanisms that allow it to recognize and neutralize pathogens. Human beings, like the rest of vertebrates, have very sophisticated defense mechanisms that interact in a dynamic network.

Functions

The Immune System has 2 main functions.

- Recognize substances (also called antigens) foreign to the body.

- React against them. These substances (or antigens) can be micro-organisms that cause infectious diseases, transplanted organs or tissues of another individual, or even tumors in our body. The proper functioning of the Immune System provides protection against infectious diseases, is responsible for rejecting transplanted organs, and can protect a person from cancer.

its bassicly asking u   to answer it in your own words does that

i think he will be okay, id probably take the dog to the vet just incase