Do Adult Cats Have Strong Immune Systems to Fight Off Viruses?

Cats, like all animals, have a powerful immune system but the effectiveness of that immune system varies from one animal to another. The strength of the immune system depends very much on the health of the animal and any deficiencies in the immune system itself.

There are two types of immune system in cats. These are called the Innate and Adaptive Systems. The Innate system is the first line of defense and consists of things like the skin, the mucus in the cat’s respiratory system, the chemicals that are in the cat’s saliva and the acid that is in the cat’s stomach.

In addition to these components of her innate system, there are specialized cells, called monocytes, that have the job of destroying anything that they do not recognize. All of these things will help to keep harmful things away from the cat’s more delicate organs.


The Adaptive System

The Adaptive System is designed to attack things like viruses and bacteria that are foreign to the cat’s system.  As an example, if a virus invades your cat’s body, the Innate System will leap into action and try to keep the virus from physically entering the cat’s body.  If the virus gets past the Innate System, the Adaptive Systems will then take over and destroy the virus within the cat’s body.

If the cat’s immune system is strong, the animal should be able to fight off the infection without assistance from the vet.  The Adaptive System is also smart enough to remember the infections that it has fought in the past.  If the same virus or bacteria enters again, the response will be faster and stronger as the Adaptive System remembers the infection.


Types of immunity in cats

The immune system in cats consists of two types of immunity.  The first is passive immunity, and this is the type of immunity that kittens receive from their mother. She will pass on antibodies from herself to her kittens, but once that immunity is used up it cannot be replaced; thus, it is known as passive.

Active immunity is the immunity that is commonly found in adult cats. This immunity comes from her Adaptive System generating antibodies as a result of exposure to a virus or as a result of an inoculation.


When the virus enters the cat’s body the immune system swings into gear, and the B-cells begin manufacturing antibodies to destroy the virus.  These B-cells work in conjunction with T-cells in the bloodstream to effectively surround and destroy the foreign matter.

If an adult cat’s immune system is compromised in any way, whether by poor health or due to illness, then the animal will not be able to fight off infection. It is extremely important to ensure your cat is regularly vaccinated and that it receives a balanced, nutritious diet to keep it in the peak of health.