Feline Infectious Anemia

Feline Infectious Anemia is a blood disease caused by the rickettsial parasite, Hemobartonella Felis. H. felis attaches itself to the cat’s red blood cells. The cat’s body then recognizes these cells as abnormal or foreign and begins to destroy them in the spleen. The resulting effect is that the cat has a severe shortage of red blood cells and thus severe anemia. For a general understanding of anemia click here.

It has not been definitively proven how cats get FIA; however, there are a few theories. FIA is currently thought to be highly contagious and most FIA+ cats are thought to either have the disease from birth (contracted from the mother) or have contracted it through a bite, scratch, or other blood transmission with an affected animal. Cats can also get the disease if bitten by a flea, mosquito, tick, or other parasite carrying the disease.

Many *normal* cats have the hemobartonella parasite on a few red blood cells. This does not indicate that they have FIA necessarily. Generally it is only once a cat is stressed in some way (other infection, other illness, moving to a new home, new pet in the home) that the parasite is then triggered. There does seem to be a high prevalence of FIA seen in cases of cats with FIP and FeLV, so if your cat has either disease and seems particularly lethargic you may want to have him/her tested for FIA.

Note: Somalis are prone to FIA so if you have a Somali that seems a little lethargic you may want ot have him/her checked out.

Symptoms to look for:


  • Lethargy
  • Depression
  • Weight loss
  • Decreased appetite
  • Pale or white ears and gums
  • Jaundice (yellowing of the skin due to liver disfunction)
  • Dehydration
  • Diarrhea
  • Incontinence
  • Increased breathing rate or wheezing


If you suspect that your cat has FIA your vet will draw blood and run a test for the presence of hemobartonella. Hemobart runs through the blood stream in cycles so you may not see it from just one blood test. From the time of infection the parasite will take 8-23 days to show up in the blood the first time, after that it cycles through the blood in intervals. Thus testing can be tricky because the last thing you want to do to an anemic cat is to take out any more blood than you need to as the cat is already destroying enough of its own blood.

Once it is determined that your cat has FIA he/she will be put on a course of tetracycline group antibiotics and possibly prednisone and an immunosuppresive drug. Your cat may necessitate one or more blood transfusions depending on how early the disease is caught and what your cat’s RBC count is. Your cat may also need subcutaneous or intravenous fluids if he/she is dehydrated. At minimum try to make sure your cat is drinking plenty of water while recovering from FIA. If caught early enough the success rate is very high.

Bear in mind that if your cat does have hemobartonella he/she will never get rid of it. Your cat will always be a carrier and you will always need to be concerned with infecting other cats and possible recurrent episodes of FIA. To ward off any future bouts of FIA you will want to keep your cat inside, feed him/her a healthy diet, treat other health problems as quickly as possible, and keep your cat’s vaccinations up to date.

Precautionary measures:

As this is thought to be a blood to blood contagious disease keep your cat out of danger from fights with unknown cats. Also keep your cat in good health and if your cat has any sort of health problem (flu, fleas etc.) take him or her to the vet asap. Make sure your cat eats a high-quality balanced diet and has clean bowls and a clean litterbox at all times.