Feline Infectious Anemia (Hemoplasmosis)

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  • At a glance

    • About: Hemoplasmosis, formerly called haemobartonellosis, is a flea and tick-transmitted disease
      caused by mycoplasmas.
    • Transmission: Flea or tick bites, through infected milk or during birth and via blood transfusion.
    • Symptoms: Loss of appetite, pale gums, fever, enlarged lymph nodes, jaundice, lethargy and weakness.
    • Treatment: Supportive as well as antibiotic therapy.

    What is hemoplasmosis?

    Also known as feline infectious anaemia (FIA), hemoplasmosis (formerly known as hemobartonellosis) is an infection caused by an unusual group of bacteria known as mycoplasmas. These bacteria have no cell wall and most of them live within or on the host cell. In the case of hemoplasmosis, the bacteria live on the walls of red blood cells.

    Until recently, the organism responsible for hemoplasmosis was known as Hemobartonella felis, since reclassification, it has been discovered that there are in fact two species involved.

    • Mycoplasma haemofelis.
    • Mycoplasma haemominutum.

    Collectively they are known as Feline Hemoplasmas, Hemotropic Mycoplasmas or Mycoplasma Hemofelis.

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

    Feline hemoplasmas attach themselves to 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, leading to anemia. It is not possible to culture Feline Haemoplasmas because they cannot survive outside the host cell.

    The disease can affect cats of any age, although it is most common in male cats between 1-3 years old.



    The natural mode of transmission is thought to be via fleas and tick bites where the parasite passes infected blood from one cat to another. Bites and scratches from infected cats may also spread the infection.

    Vertical or lactogenic

    Infected queens can pass on the infection to their kittens although we do not know if this is in utero, during the birth process or via the milk.

    Blood transfusion

    Infection can occur if a cat receives a blood transfusion from a cat infected with hemoplasmosis.


    Symptoms vary depending on the number of red blood cells infected, the stage of the parasitic infection, the health status of the cat and the rapidity of infection. Clinical signs usually include those associated with anemia and may include:

    Untreated, FIA can cause death.


    • Stained blood smear: A thin film of blood is stained and studied under a microscope for the presence of organisms on the red blood cells. This can return a false negative as the pathogen comes and goes in cycles. Several blood samples taken over a period of days will be necessary.
    • Polymerase chain reaction (PCR): This is a test that detects the organism in the blood. It greatly amplifies the DNA of the organism, even in small amounts.


    Treatment of hemoplasmosis includes both supportive care and antibiotics.

    • Antibiotics oxytetracycline or doxycycline.
    • Corticosteroids to diminish the immune-mediated component of the disease process.
    • Severely anaemic cats may require blood transfusions.
    • Cats having breathing difficulties may require oxygen.

    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.


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


    • Julia Wilson, 'Cat World' Founder

      Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio