Feline Infectious Anaemia (Haemobartonellosis)


Haemobartonellosis in cats is caused by a very small micro-organism, a mycoplasma called mycoplasma haemofelis. It has been reclassified; its name used to be haemobartonella felis, after its discoverer which gave the condition its name, which has not been changed. It is mainly spread by flea and tick bites, but can also be spread directly cat-to-cat by a bite. The causative mycoplasma can only live in the blood, so it has to be a direct contact, from the tick or flea which has bitten an infected cat, or a cat with the organism in its blood. The only other way that the infection can spread is from a nursing queen to her kittens.

Diagnosis of FIA

Diagnosis can be tricky, as the symptoms do mimic so many other conditions, but if the vet suspects haemobartonellosis in a cat a simple blood sample is usually enough to confirm it. The blood is spread in a very thin film, one cell thick, on a glass slide and then stained with dye. The haemobartonella organism shows up as a dark purple spot in the red cell. Sometimes, the cells have more than one and this is more commonly seen, as cats with only the odd one or two mycoplasma in their bloodstream don’t usually show any symptoms and so wouldn’t be being tested, unless they have another condition. Cats with the Feline Leukaemia Virus often also have haemobartonellosis.

Symptoms of Haemobartonellosis

Like many cat illnesses, the symptoms of haemobartonellosis are hard to pin down. In slight cases there may be none at all, except perhaps a slight malaise when the mycoplasma is first picked up. If it is caused by a bite from another animal, the symptoms are often put down to the shock of the bite and also a general infection. If it is from a tick bite, then sometimes again the general unwell behaviour of the cat is put down to the bites of the ticks. In other animals, a profound anaemia develops very quickly and the cat quickly becomes very lethargic, stops eating, gets heart palpitations with rapid breathing and becomes jaundiced. If it doesn’t get treatment, it can die of the anaemia and the associated heart problems. Haemobartonellosis is quite commonly found in cats which are ill with other conditions, but it is almost impossible to tell which illness came first, except sometimes from anecdotal evidence of bites and other things which the owner may have noticed.

Treatment of FIA

Antibiotics are the first line of treatment and these have to be given for at least three weeks to have any effect. This is not always a good time for the cat, as some are quite badly affected by antibiotics and so they will need support from a good diet and stress free conditions. If this has no effect, then a course of prednisolone is given, which destroys red cells in circulation. This may seem a mad thing to do, as the cat is profoundly anaemic already, but it breaks the life cycle of the mycoplasma and is often very beneficial. The cat will need transfusions afterwards, to restore its haemoglobin level and the whole treatment will take quite a while and will be costly.


There is no vaccine against haemobartonellosis, but as most cases are spread by ticks and fleas, it makes sense to protect against them, and then the likelihood of the cat contracting an infective bite is much less. Keeping up with prophylactic medication is vital and the careful owner will keep a note of when the doses are due. Even so, the occasional bite is possible, so this is not a complete protection. If your cat is a bit of a scrapper, then there is little you can do to protect it from the bites of other cats. If your male is aggressive and you don’t want to breed from him, castration is possibly the answer, but not all toms become docile after neutering. If your cat is generally aggressive towards others, there are various medications to calm it down, either to be added to the food or used as a diffuser in the air. But the bottom line is that if a cat is an outdoor cat, it will run the risk of contracting haemobartonellosis if it is allowed to roam at will.

The pros and cons have to be considered carefully and the owner will have to decide as to whether the risk of the cat contracting FIA, but living the life it has always known, or keeping it protected in the main from the condition, but having to keep it in the house is the better choice. Work done in various veterinary schools put the infection rate at around 23% and as not all of these would present with symptoms and those which did would have a reasonable rate of recovery, such draconian measures to keep the cat safe may be considered by most owners to be going a little far in the care of a pet.


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