Introduction
All cases of feline infectious anemia are caused by the bacteria Mycoplasma haemofelis, and the condition it causes in cats can either be very mild or quite severe. There is a related bacterium, Mycoplasma haemominutum which may also cause a mild form of feline infectious anemia, but it is not as common.
Types of Feline Infectious Anemia
Once a cat has been exposed to the bacteria Mycoplasma haemofelis, a condition known as feline infectious anemia, or haemobartonellosis, may occur. Why some cats develop this condition when they are exposed to the bacteria, and others do not remains a mystery. Cats that do not develop the feline infectious anemia condition become asymptomatic carriers, meaning they do carry the bacteria but they do not develop any symptoms or illnesses as a result.
Cats that develop feline infectious anemia can be affected quite differently by the bacteria. Some cats show only mild symptoms such as slight anemia or fever, other cats have severe anemia that may become so advanced a blood transfusion is needed. Cats with feline leukemia are usually affected quite severely by the infection, but the exact reason of why they are affected is still unknown.
The Mycoplasma haemominutum is a bacteria parasite as well, but it is much smaller in size than Mycoplasma haemofelis. While Mycoplasma haemominutum attacks the red blood cells, it does not cause serious forms of anemia. If a cat is infected with feline leukemia and becomes infected with Mycoplasma haemominutum, then the cat is at an increased risk for developing cancers and blood marrow disorders.