The canine immune system is the command center for a dog's defensive troops. This system scans the molecules of foreign objects (antigens) in a dog's body and sets a course to eliminate them.
Innate and Adaptive Systems
Dogs have two divisions within their immune systems based on their function: the innate and adaptive systems.
The
innate immune system is on the forefront of a dog's defenses. They are
like the bouncers of a dog's body and work hard to keep foreign
molecules out. This division of the immune system doesn't change its
reaction to invaders after multiple exposures. Parts of a dog's body
that are part of this innate immune system include mucous, skin,
chemicals in saliva and stomach acids.
The adaptive immune
system is like the special ops. division in a dog as they combat
specific invaders. The adaptive system changes its tactical methods
based on the type of substance that's invading a dog's body. The agents
within this defensive system have communication with the each other,
retain a memory of foreign substances, and change their combat methods
based on those memories or changes the invaders have made.
The
innate and adaptive immune systems work together. Hopefully a dog's
invaders are stopped by the innate system, which is first in line, so a
dog doesn't experience any illnesses. However, if an invader does get
past the innate system, the adaptive system works as a backup team to
help a dog recover from the illness that attacked him.
Dog Immune System Cells
A dog has special agents, cells, in his immune system that have
special functions: monocytes, macrophages, granulocytes and
lymphocytes.
Monocytes and macrophages are cells that begin a
dog's bone marrow and travel into the body. Monocytes travel into a
dog's blood stream and the macrophages go into the tissues. These cells
kill and digest antigens and give information about the invaders to
other cells.
Granulocytes come in many different forms and are
part of the innate immune system. They, too, travel from a dog's bone
marrow to the bloodstream and tissues, find an antigen, and kill and
digest it. Granulocytes, however, don't share information about the
invader with other cells.
Lymphocytes are the trained forces
within the immune system. As they mature, they are trained on how to
best protect the area of the body they'll be assigned to.
Canine Immunity Building
A dog can build his immunity in two different ways. First, a dog's
immune system is built when he's exposed to an antigen because of an
infection or a vaccination. When this happens, a dog's body creates
immunity to an antigen on its own and creates antibodies throughout a
dog's life, a process called active immunity.
When defenses are given to a dog, this is called passive immunity. Examples of this include bone marrow transplants or antibodies puppies receive from their mothers before they're born.
The
canine immune system is complex and extremely organized. When this
system isn't coordinated an autoimmune disease or negative reaction can
result. It's important that a dog be in good physical condition so his
immunity remains strong.