Cat - Anaemia

Anaemia is the term used to describe a decreased amount of red blood cells in the circulation and is a relatively common problem in cats. Red blood cells are important for carrying oxygen from the lungs to all the organs of the body. If the number of red blood cells is reduced, organs can become short of oxygen.

What signs will anaemia cause?

The signs of anaemia will depend on the severity, and also on the speed of onset of the anaemia, and the underlying cause. The speed of onset is particularly important because if the anaemia develops slowly, the cat can adapt to having a much lower than normal number of red blood cells and may show no signs at all until the anaemia is extremely severe. If the onset of the anaemia is much faster the signs of disease can be more sudden and severe e.g. extreme weakness and collapse. Most often, the signs will be vague, with the cat just being more lethargic than normal, sleeping a lot more, and gradually becoming weaker and inappetant. Anaemic cats may also exhibit something called 'pica' which is when they try to eat non-food substances, often stones or cat litter, or lick paving slabs or walls. Depending on the underlying cause, other signs may also be present e.g. jaundice. If haemorrhage (a bleed) into the intestine is the cause of the anaemia, owners may notice the cat passing very dark or black faeces, representing digested blood.

What can cause anaemia?

There are a vast number of causes of anaemia in cats, and the causes are usually spilt into 2 main groups, termed regenerative and non-regenerative anaemia. This refers to whether the bone marrow is responding to the anaemia and producing new red blood cells (regenerative) or not (non-regenerative).  Bone marrow is found in the centre of bones of the body and its job is to produce new blood cells to replace old onese.

Regenerative anaemia is caused by two main groups of disorders, either blood loss or excessive breakdown of red blood cells in the circulation. Blood loss can be a result of trauma, a bleeding disorder, tumour, or ulceration in the gastrointestinal tract (guts). Excessive breakdown of red blood cells in the circulation can occur for a number of reasons, including infectious diseases such as feline leukaemia infection, or Haemoplasma (a red blood cell parasite) infection, an abnormal reaction to certain drugs, toxicity (e.g. paracetemol, ingestion of products containing onions or garlic), tumours, an abnormality of the immune system and rarely in some breeds due to a genetic abnormality.

If the anaemia is non-regenerative (ie the bone marrow is not responding to the anaemia and producing new red blood cells), this is reflective of either a disease within the bone marrow, or a severe disease elsewhere in the body that is stopping the bone marrow from functioning properly (e.g. kidney disease).

How is anaemia and the underlying cause diagnosed?

Anaemia is diagnosed by performing a blood test to assess the number of red blood cells and haemoglobin in the blood. Your veterinary surgeon will look at blood cells on a microscope slide (or send this off to a laboratory) and by doing special stains and looking carefully at the size and shape of the cells, will be able to determine whether the anaemia is regenerative or non-regenerative, in addition to possibly giving other clues as to the underlying cause. For example, toxicities, or problems with the immune system can cause specific changes to the cells which can be seen by careful examination.

Further blood tests to look for jaundice, and problems with other organs such as the liver and kidneys will also need to be performed in addition to tests for the infectious diseases like feline leukaemia infection. If your veterinary surgeon suspects that your cat has a bleeding disorder special blood tests may have to be performed to assess the ability of your cats blood to clot. Radiographs (x-rays) and ultrasound examinations may also be required to look for signs of internal bleeding or tumours, if blood loss is suspected. If the anaemia is found to be non-regenerative, a bone marrow biopsy will be required to identify the underlying cause.

How is anaemia treated?

The treatment will very much be dependent on the underlying cause and the severity of the anaemia. If the anaemia is very severe or has occurred very quickly, a blood transfusion could be required, just until more specific treatment can be initiated. Before your cat receives a blood transfusion, it will have to have a test to determine its blood type to ensure that matching blood is given.