What is haemobartonellosis?

Also known as Feline Infectious Anaemia (FIA), until recently, the organism responsible for feline infectious anaemia was known as Hemobartonella felis. Since reclassification, it has been discovered that there are in fact two species of "mycoplasma" which are individually known as Mycoplasma Haemofelis (also known as large strain) & Candidatus Mycoplasma Haemominutum (also known as small strain). Collectively they are known as Feline Haemoplasmas.

M. Haemofelis can cause illness in healthy cats, however C. Mycoplasma Haemominutum appears to be more of an opportunistic parasite, typically infecting cats with an underlying condition such as FIV or FeLV.

Feline Haemoplasmas are microorganisms in the class Mollicutes; which are an unusual group of bacteria. They have no cell wall & most of them live within or on the host cell. It is not possible to culture Feline Haemoplasmas because they cannot survive outside the host cell.

Feline Haemoplasmas attach themselves the wall of red blood cells.  The body's immune system tries to destroy these parasites but in the process also destroys the affected red blood cells, causing anaemia.

What are the symptoms of haemobartonellosis?

Symptoms vary depending on the  number of red blood cells infected, the stage of the parasitic infection,  the health status of the cat & the rapidity & of infection, but can include;

How do cats become infected?

Infected queens can pass on the infection to their kittens although it's not entirely known if it is in utero, during the birth process or via the milk.

The natural mode of transmission is thought to be via fleas & ticks, bite wounds may also spread the infection between cats.

It is possible for cats to become infected during a blood transfusion.

How is haemobartonellosis diagnosed?

There are two methods to test for haemobartonella.

Stained blood smear: A thin film of blood is stained & studied under a microscope for the presence of organisms on the red blood cells.  However, this can result in a false negative as the infection seems to come about in cycles, so several blood samples taken over a period of days may be required.

Polymerase Chain Reaction (PCR):  This is a test which detects the organism in the blood. It greatly amplifies the DNA of the organism, even in small amounts.

How is haemobartonellosis treated?

Antibiotics oxytetracycline or doxycycline.

Treatment with a glucocorticoid such as prednisolone may also be prescribed to diminish the immune-mediated component of the disease process.

Severely anaemic cats may require blood transfusions.

Carrier Cats:

Recovered cats can still carry the organism in small numbers in their blood, although they will show no clinical signs. They may have a relapse in the future, especially under times of stress or they may remain free of the disease for life.

How do I prevent haemobartonellosis in my cat?

Proper flea & tick control on your cat, including keeping the environment free of parasites.