Cat - Feline Infectious Anaemia

What causes feline infectious anaemia (FIA)?

FIA is caused by a very specialised group of bacteria called Haemoplasmas, which attacks the cat's red blood cells within the circulation, leading to anaemia. There is more than one type of Haemoplasma and there are differences in the importance of individual types. Some types can infect a cat without any resultant anaemia.

How would an owner recognise FIA in the cat?

Cats are very good at hiding anaemia until it is quite severe. The earliest indication may be pallor of the mucous membranes - the conjunctiva (lining of the eye), gums and tongue appear white or pale instead of the normal pink colour. It can be difficult to assess the mucous membranes in some cats - occasionally they may normally appear rather pale and there are causes of pallor other than anaemia. Another indication of anaemia can be pica where the cat likes to eat unusual things and may be noticed licking stones or eating its cat litter. As the anaemia becomes more severe the cat may become lethargic and breathless if stressed or after any exertion. In FIA there may be loss of condition, poor appetite, weight loss and occasionally high temperature, occasionally jaundice is seen - usually only in very severe, acute cases.

How is FIA diagnosed?

Previously diagnosis was based on identifying the organism on specially prepared and stained blood films, but this method of diagnosis is very unreliable. It is now diagnosed on a blood test which your vet will send to a specialist laboratory that detects the organism's DNA in the blood. This test also determines which type of Haemoplasma is present and the amount of the DNA which can help to decide whether or not the infection is likely to be significant.

Can FIA be treated?

FIA is treated with a particular type of antibiotic. The treatment is very effective but the drugs do not reliably eliminate the parasite from the body. Sometimes infection can recur once treatment is stopped so careful monitoring blood tests is required. In severe cases where the cat becomes weak due to very severe anaemia, a blood transfusion may be required.

Does a diagnosis of FIA have any implications for my other cats?

Although FIA is a disease caused by an infectious agent, it may not prove to be a problem in other cats living in the same household. The way it is spread between cats is not certain. Cat bites and fleas may spread the parasite but this has not been proven and other methods may be involved. Fighting therefore represents a risk of spread of infection. Flea infestations should be treated - indeed the presence of fleas may make anaemia of any cause more severe.