Anaemia in dogs: symptoms, causes, treatment

Is anaemia painful for dogs?

As a rule, anaemia is not painful for dogs. Yet it is worth bearing in mind that in people it can be associated with headaches, chest pains and cramping pains in the legs, so maybe we should assume that dogs may sometimes get similar symptoms.  

What are the symptoms of anaemia in dogs?

The main symptom of anaemia is a progressive weakness, which may come on gradually or be very sudden depending on the underlying cause. A dog that has developed a severe anaemia may collapse. On closer examination, a dog with anaemia will have pale gums and a rapid heart rate (tachycardia). Other signs may develop if the anaemia is more severe, including weak pulses and a heart murmur.

What causes sudden anaemia in dogs?

Anaemia has many different possible causes. Broadly, it can be caused by: a loss of red blood cells (haemorrhage), an increased destruction of red blood cells (haemolysis); or a decreased production of red blood cells.

If anaemia has developed very suddenly, it is more likely that is has been caused by haemorrhage. The haemorrhage may be external, in which case it will be very obvious as blood loss will be visible. Internal haemorrhage into body cavities will not be so apparent.

From a dog's ruptured splenic tumour to pale gums

A common cause of internal haemorrhage in dogs is rupture of a splenic tumour. These splenic tumours are quite delicate and prone to sudden rupture with blood loss into the abdomen. When this happens the dog will suddenly collapse and have very pale gums. Certain breeds have an increased predisposition to splenic tumours with German Shepherds at the top of the list.

Anaemia caused by haemolysis can develop rapidly although not as fast as with blood loss. Anaemia caused by a decreased production of red blood cells will develop gradually.

How do you fix anaemia in dogs?

The absolute essential for fixing anaemia in dogs is to get a prompt and accurate diagnosis. The diagnosis of any medical condition starts with a thorough history and clinical examination – and anaemia is no different.

If clinical signs suggestive of anaemia are present, the next step in diagnosis will be blood tests. Anaemic dogs will have a low-packed cell volume (PCV). The PCV is the percentage of the whole blood volume that is made up of red blood cells and a low PCV confirms that a dog is anaemic. A blood smear will be examined and this relatively simple test will give the veterinary surgeon really useful information.  

For example it will show whether the anaemia is regenerative, in other words whether the dog is able to make new red blood cells. It may also show whether there appears to be damage to red blood cells, which would suggest the anaemia is caused by destruction of red blood cells. Comprehensive blood tests should be performed to assess general health and organ function to screen for underlying disease and give further diagnostic clues as to a potential cause for the anaemia.

Tests, treatment and transfusions

While running these initial tests, treatment will be initiated to stabilise the dog. This is likely to include intravenous fluids to support the circulation, measures to control any bleeding and blood transfusions, if the anaemia is severe.

Further tests will then be done to narrow down the precise cause, if it has not already been established. These tests may include abdominal ultrasound and chest x-rays looking for evidence of internal haemorrhage, together with more blood tests to assess such things as whether the clotting function of the blood is normal. In some cases a bone marrow biopsy will be needed.

Once a diagnosis has been reached, in many cases it will be possible to fix anaemia in dogs. The number of possible specific causes and hence treatments are very extensive. Curing the anaemia may involve surgery or medical treatment, and may include further blood transfusions, antibiotics and immunosuppressive drugs. An accurate diagnosis gives the best chance of a cure.

What medications cause anaemia in dogs?

There are certain medications that have been associated with the onset of anaemia in dogs, for example sulphonamides, which are a type of antibiotic. Additionally, there may be a link between immune mediated haemolytic anaemia and vaccination. In order to protect the body against infectious diseases, vaccines stimulate the immune system. This has hugely beneficial effects and countless dogs’ lives have been saved by the routine use of vaccines against infections such as parvovirus, Leptospirosis and distemper.

In a very small minority of cases, the dog’s immune system reacts abnormally to the vaccine and this abnormal immune response results in the production of antibodies directed against the dog’s own red blood cells. It cannot be stressed enough though that the benefits of vaccination hugely outweigh any negatives.

What is a good source of iron for dogs?

Iron-deficiency anaemia is a relatively common condition in people, but it does not tend to be such a problem in dogs. Dogs may suffer from iron deficiency if there is chronic (lasting a long time) low-grade blood loss, for example with a bleeding stomach ulcer. There is little point in supplementing your dog with iron without treating the underlying disease. Yet assuming that has been addressed, iron supplements may be of benefit, but you should discuss this with your veterinary surgeon. In many cases, controlling the ongoing bleeding and a complete nutritionally balanced diet will be all that is required.

What causes low red blood cells in dogs?

The technical term for low red blood cells in dogs is anaemia. Anaemia has very many different causes, which can be grouped into three broad categories: loss of red blood cells (haemorrhage); destruction of red blood cells (haemolysis): or decreased production of red blood cells by the bone marrow.

Haemorrhage can be external or internal. External haemorrhage from a wound will usually be immediately apparent to both you and a veterinary surgeon. Internal haemorrhage will not be so obvious. There are a number of possible sources of internal haemorrhage that are likely to be investigated with scans and x-rays. Internal haemorrhage can occur as the result of trauma in a road accident for example, or may be caused by a spontaneous bleed from a growth or stomach ulcer. The risks of haemorrhage are increased if the ability of the dog’s blood to clot is impaired.

A dog's immune system, vaccinations and bone marrow

The cause of haemolysis is not always known. Frequently it will be immune-mediated, in other words caused by the dog’s own immune system. The immune system produces antibodies to help fight off infections, but sometimes this system goes a bit awry and autoantibodies are produced. If these attack red blood cells, the dog will become anaemic. Almost anything that stimulates the immune system can trigger an abnormal immune-mediated response, including certain bacterial infections and vaccination. This abnormal response to vaccination is very rare though and the benefits of vaccination far outweigh any risks.

Red blood cell production is dependent on a healthy functioning bone marrow. The bone marrow makes red and white blood cells and platelets, which help the blood to clot. Red blood cell production can be reduced, if there is disease of the bone marrow or in response to other illness causing bone marrow depression.

How do you treat anaemia in a dog at home? 

There are no situations where it is advisable to treat anaemia in dogs at home. Anaemia is very serious and has very many possible causes. Often it can be successfully treated, but this is dependent on prompt veterinary care.

What are regenerative and non-regenerative anaemia in dogs?

Anaemia can be classified as either regenerative, in which new red bloods are being produced by the bone marrow, or non-regenerative, when there is no production of new red blood cells. Regenerative anaemia tends to be caused either by blood loss (haemorrhage) or destruction of red blood cells (haemolysis). Non-regenerative anaemia is usually caused by a problem with the bone marrow.

It is possible to establish whether anaemia is regenerative or non-regenerative by looking at a blood smear under a microscope. With a regenerative anaemia large immature red blood cells called reticulocytes will be seen.

Regenerative anaemias tend to carry a better outlook (prognosis) than non-regenerative anaemias, but there are exceptions to this rule.

Is there a special anaemic dog diet?

A complete balanced diet with all the right nutrients is all that is required for most dogs with anaemia. Keeping their calorie intake up, at a time when they may have lost their appetite, is important. As such, making sure that the food is highly palatable will help tempt an unwell dog to eat. Anaemia cannot be fixed with particular diets, but by feeding a good quality balanced diet you will help to give your dog the best chance of recovery.

What causes autoimmune haemolytic anaemia in dogs?

In autoimmune haemolytic anaemia there is an abnormal destruction of red blood cells (haemolysis). This is caused by the production of antibodies directed against the dog’s own red blood cells, also known as autoantibodies.

Autoimmune haemolytic anaemia is also known as immune mediated haemolytic anaemia (IMHA) and is the most common cause of haemolysis in dogs. Sometimes the cause is not known, in which case it is known as idiopathic. In other cases it may be secondary to the administration of some medications or vaccines. Vaccines cause stimulation of the immune system and in a tiny minority of cases the immune system reacts abnormally and produces autoantibodies. IMHA may also occur secondary to some infections including babesiosis and ehrlichiosis, which are spread by ticks, or secondary to certain tumours.  

How can I help my dog with anaemia?

The most important thing that you can do for a dog with anaemia is to seek urgent veterinary attention. Once your veterinary surgeon has reached a specific diagnosis and hopefully stabilised the anaemia, your dog may be able to come home to continue their treatment and recovery. So what type of things can you do to aid your dog’s recuperation?

A high quality, highly palatable complete diet is most important. While home-cooked food such as chicken may help in tempting an unwell dog to eat, it should ideally not make up the majority of their food intake. It is really hard to formulate a diet that contains all the essential nutrients for your dog yourself. Ask the veterinary surgeon for their advice on the most suitable food for your dog.

You may well find that in the early stages of recovery, your dog has no energy for walks. When your dog starts to feel better, it is still really important that they do not over exert themselves, so you should still keep exercise levels to a minimum. Plenty of rest is really important for recovery.

When should I see a vet?

If your dog seems unwell in any way, it is always best to seek veterinary advice. In particular if they seem weak and wobbly, as it might be a sign that they are anaemic. A quick look at your dog’s gums by lifting up their top lip may reveal gums that are pale rather than a nice healthy pink colour. If in doubt, do not delay and get your pet to the vets as soon as possible.