Disseminated intravascular coagulation (DIC)

Disseminated intravascular coagulation (usually known as DIC) is a serious condition in which the blood clotting system becomes overactive. Small blood clots start to form within the blood vessels and this uses up all the factors needed for normal blood clotting. The result is spontaneous and uncontrolled bleeding which, if left untreated, will prove fatal. Both acute and chronic forms of DIC can occur. Acute DIC is more severe and develops more quickly.

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In a normal animal, blood clotting is tightly controlled by a complicated interaction between specialist blood cells and proteins in the blood. If there is a damage to a blood vessel, collagen is exposed in the wall. This collagen attracts a special type of blood cell – the platelets. The platelets plug the hole in the wall and then release chemicals which react with other chemicals in the blood to form fibrin strands. These fibrin strands form a sticky meshwork which traps the platelets in place and forms a stable blood clot.

In DIC this clotting process is activated by cell damage caused by inflammation or cancer. Small blood clots form within the blood vessels which uses up the clotting proteins and platelets. This means that these are not available when they are needed if blood vessels are damaged. So, paradoxically, although there is an overactive clotting system the animal suffers from a bleeding tendency.

The tiny blood clots forming in the vessels within the liver and kidneys can result poor blood supply to other organs and cause breathing problems, neurological disturbances, kidney failure, gastrointestinal problems and liver damage.

DIC develops as a consequence of an underlying disease so there may have been signs of other illness, such as a poor appetite or depression, or you may already be aware that your pet has cancer. The signs of DIC are often not very specific and develop over a few days, almost any organ can be affected and, if there is bleeding, this may occur internally so you might not notice it. Bleeding may only occur in 3 in 20 cats with DIC. There might be small bruises on the skin or gums, however these can also be difficult to see in cats with dark skin and in furred areas. Bleeding around the gumline and nose bleeds are also typical of the type of bleeding seen in DIC. It is common for cats with DIC to continue to ooze blood from any site where blood has been collected from a vein. Gastrointestinal signs might include vomiting and diarrhea (both of which may contain blood). Other signs relate to secondary damage to other organs such as kidney damage resulting in your pet ceasing to produce urine or blood clots lodging in the lungs causing difficulties in breathing.

In most cases there will be a history of severe inflammation, trauma, or previous cancer before the development of DIC. The sudden development of serious signs affecting multiple parts of the body are unusual and worrying. If this occurs along with signs of spontaneous bleeding your veterinarian may immediately want to do some laboratory tests to investigate. A blood sample can be collected to check that platelets are present and to measure clotting times.

Other samples may need to be taken to look for damage in other organs, and specialist imaging techniques can be used to look for damage caused by clots, within the lungs or kidneys, for example.

DIC develops when damage within the body stimulates over-reaction in the clotting system. Tumors of the blood vessels such as hemangiosarcoma, or lymphoma can be associated with DIC, as can mammary tumors that have spread. Many infectious diseases, eg bacterial sepsis secondary to panleukopenia, FeLV associated, FIP related inflammation can also result in DIC. A range of other serious diseases: inflammatory conditions (like pancreatitis), heat stroke, shock, autoimmune-mediated hemolytic anemia, snake bites and severe trauma or surgery can also be involved.

There are 2 steps in treatment of DIC. Firstly, to provide support to keep the patient alive, whilst secondarily trying to identify (and, if possible, treat) the underlying cause.

A blood transfusion using fresh blood or plasma will supply much needed clotting factors, but is only a short-term measure as these will rapidly be used up again if the DIC continues. It is important to maintain blood pressure to keep the organs supplied with blood and intravenous fluids are likely to be given, especially if the patient is in shock. Other drugs may be given to try to reduce the clotting reactions.

Unfortunately, the outlook is not good for animals with DIC. Unless an underlying cause can be identified the chances of recovery are very small. Antibiotics will be given, especially if sepsis is suspected and a patient with heat stroke can be cooled. Even if the cause is identified it may be difficult to treat as many of the conditions are very serious in their own right.

If you are concerned about any aspect of your pet’s health always contact your veterinarian for advice. DIC is a very serious condition but the best chances of success are achieved with early diagnosis and treatment.