Feline Infectious Anaemia - What You Need To Know

Feline infectious anaemia (FIA) is also known as a haemoplasma infection, which is the term used to describe a health condition caused by a certain type of bacteria known as mycoplasma. These mycoplasmas, collectively called haemoplasmas, infect the body’s red blood cells, leading to them becoming damaged, which can in turn lead to anaemia.

In this article, we will look at FIA in more detail, including how it occurs, how it is spread, what it means for affected cats, and how it can be treated. Read on to learn more.

What causes feline infectious anaemia?

Haemoplasmas begin life on the outside surface of red blood cells, but can, in some cases, begin to invade the body of the red blood cells themselves. Just the process of attaching to the outside of the cells damage them, leading to the death of the individual cell itself, and if this happens in large enough quantities, anaemia can develop as a result of this.

To further complicate matters, as the cat’s own immune system begins to attack the haemoplasmas as part of the body’s natural defence against invaders, this too can increase the die-off rate of the body’s red blood cells, worsening the problem.

It is not known for sure how many different species of haemoplasma exist in total, but there are at least three species that can be found in cats, each of which has a slightly different deleterious effect on the red blood cells, and present with slightly different symptoms.

• Mycoplasma haemofelis are the type of haemoplasmas that are most likely to lead to acute and serious anaemia in the cat.


• Mycoplasma haemominutum, and also mycoplasma turicensis can also be found in cats, but are likely to produce a much more mild form of anaemia, or in some cases, will not cause any problems at all.

It is entirely possible too that a cat may have Mycoplasma haemofelis bacteria present within the body without this leading to any problems, but should the cat have a compromised immune system, particularly if this is caused by another serious condition such as FIV or FeLV, the bacteria are likely to become problematic as the immune system of the cat is less able to handle them.

The symptoms of FIA in cats

The core symptoms of FIA in cats include anaemia, which may also come accompanied by a higher than normal body temperature during the early stages of the condition. Other symptoms can include weakness and lethargy, loss of appetite, and pale gums. In some cats, the condition will also lead to an increased heart rate and respiration rate, and potentially, weight loss.

However, all of these symptoms can also be indicative of various other forms of anaemia too, and so do not definitively indicate a diagnosis of FIA.

How is FIA diagnosed?

In order to get a definitive diagnosis of FIA, your vet will need to run a blood test to detect the presence of the haemoplasmas in the blood, which usually takes the form of a molecular test that detects specific genetic markers of organisms such as haemoplasmas in the bloodstream. Such testing will also identify which of the three species of haemoplasmas are present, which can help with deciding on how to proceed with care.

Treatment for FIA

Because FIA is a bacterial infection, antibiotics are usually used to clear it, and in most cases, a reasonably long course of antibiotics will be required. If the cat’s own immune system is found to be contributing to the ongoing destruction of the body’s red blood cells, corticosteroids may also be prescribed in order to suppress this action of the immune system.

If the anaemia is very acute and placing the life of the cat at risk, blood transfusions may also be required to support life during recovery. Fortunately, the type of anaemia caused by FIA is known as a regenerative anaemia, meaning that it does not stop the body’s bone marrow from actually producing healthy red blood cells in the first place, and so over time, once the bacteria itself has been eradicated, red blood cell production will return to healthy levels.

Preventing transmission of FIA

FIA is not a condition that your cat can be vaccinated against, and the condition is not classed as a breed-specific or congenital one, so no particular type of cat is considered to be more at risk of the condition than others. Some cats that carry the bacteria may never become ill with it themselves, but they can still pass the bacteria onto other cats, and of course, also run the risk of the bacteria becoming problematic if at some point their own immune system becomes compromised.

Even after recovery from the condition with successful treatment, a cat that has suffered from FIA once may go through repeated incidences of the condition in the future, and this is particularly likely to occur at times when the cat might feel stressed or unsettled, as this in itself can lead to the suppression of the cat’s immune system.