Cat Anaemia

Cat Anaemia

Cat Anaemia

Cat anaemia is not always a condition that is very visible, but the signs will be clearly apparent in your cat’s behaviour. First and foremost, it will be lethargic and less active than usual. Where there is no obvious bleeding, a routine blood test can confirm a case of anaemia. The shortage of red blood cells can be easily ti detected by examining a blood smear under the microscope. But the precise cause may be hard to pinpoint, making treatment tricky.

Cats suffering from anaemia will be very lethargic. The disorder can be caused by anything from an infestation of fleas to a nutritional imbalance. (White cats are no more susceptible than others.)

Cat Anaemia occurs when there is a reduced number of red blood cells in circulation. These cells carry oxygen from the lungs through the body and return carbon dioxide via the venous system. This is why a cat suffering from anaemia will have pale, whitish gums rather than gums that are a normal, healthy shade of pink. Anaemia can develop rapidly as a result of blood loss caused by haemorrhaging, either because of an external wound or, more seriously, internal bleeding out of the circulatory system into a body cavity.


Most cases of anaemia tend to be chronic by nature however, meaning that they arise slowly over a period of time.

The red blood cells are produced in the bone marrow and released into the circulation as others are removed and broken down into waste materials. If the bone marrow is damaged, for example by radiation or more commonly by drugs, then this slows down the production of red blood cells, causing a progressive anaemia. A form of cancer (lymphosarcoma) also has this effect.

The cat’s inability to effectively break down many chemicals in its liver means that even apparently harmless drugs such as aspirin and the antibiotic chloramphenicol can result in anaemia, thanks to their depressant effect on the production of red blood cells in the bone marrow.

A dietary deficiency of iron and/or copper is another possible cause of anaemia, but this is rare in cats fed on commercially-prepared diets, as such foods contain supplements of these chemicals at appropriate levels.

Cats are at risk if they hunt and consume rodents which have been affected by warfarin.This poison acts by interfering with the blood clotting mechanism. This encourages leakage of blood through damaged blood vessels, leading to internal haemorrhaging – which is likely to be fatal.


It is also possible for red blood cells to be destroyed in the circulation by poisons and bacteria especially Haemobartonella felis, which is the cause of feline infectious anaemia.

Severe blood loss as the result of parasites can also lead to anaemia. Because of their size, kittens that are heavily infested with fleas are particularly susceptible.

Our vet has diagnosed that our cat is suffering from feline infectious anaemia. What is this condition?

It is caused by a bacterium called Haemobartonella felis, which multiplies in the blood cells and causes them to rupture; the bacteria then move on to attack other cells. In the early stages, the cat may develop a temperature up to 41°C (106°F). Later symptoms include breathing difficulty and an enlarged spleen.

How is this illness treated?

Antibiotic drugs of the tetracycline group may be needed. In severe cases, blood transfusions may also be necessary.

How is it spread?

Transmission occurs as the result of an infected bite. It can also pass from a pregnant cat to her kittens. There is even a risk of infection after a blood transfusion.