Thrombocytopenia in Dogs

Thrombocytopenia is a disease found both at male and at female dogs regardless of their age and breed and it is as a reduction of platelets (thrombocytes), a component of the blood cell that play a major part in the coagulation process.

Symptoms of Thrombocytopenia in Dogs

The normal platelet level has to be above 40,000 per micro liter of blood. Under this level bleeding and bruises will easily appear. Some symptoms of thrombocytopenia are:

  • Loss of appetite
  • Lethargy
  • Weakness
  • Larger hemorrhages under the skin, especially on the ventral abdomen
  • Bleeding from the mucous membranes
  • Nose bleed (epistaxis)
  • Small red spots on the white part of the eyes, the skin or gums
  • Bruises on the skin (ecchymosis)
  • Pale mucous membranes
  • Blood in the urine
  • Blood in the stool or black, tarry stool
  • Prolonged bleeding after an injury or a surgery
  • Hemorrhages in the eye, in very severe cases

Causes of Thrombocytopenia

There are four main processes that can cause thrombocytopenia:

  • The production of a smaller number of platelets by the bone marrow
  • The destruction of the platelets by the immune system; the immune system destroys the platelets because it doesn’t recognize them as useful cells
  • The use of a larger number of platelets in the clotting process
  • The removal  of the platelets from the general circulation

Chemotherapy or radiotherapy, bone marrow diseases such as leukemia or aplastic anemia, estrogen medications as well as other types of medication (e.g.chloramphenicol medication) can decrease the number of platelets.

In certain cases such as disseminated intravascular coagulation (DIC), vasculities, hemangiosarcoma or endotoxic shock, a larger number of platelets are used than can be produced by the bone marrow.

If the pet is affected by splenomegaly or splenic torsion the platelets are stored in certain organs.

In addition, a bacterial agent called rickettsia spread through ticks can cause Rocky Mountain spotted fever or ehrlichiosis, which can trigger thrombocytopenia.

Diagnosing Thrombocytopenia in Canines

To identify the disease correctly and to exclude other diseases multiple diagnostic tests can be done:

  • A complete history
  • A thorough physical examination to detect the signs of other diseases
  • A complete hemogram including a platelet count
  • A coagulation profile which tests the presence of the clotting factors
  • Serum biochemistry tests to evaluate general health and to detect abnormalities in other organs
  • Immune system function tests
  • Bone marrow aspiration
  • X-ray of the chest or abdomen also to check the presence of  other diseases such as infections or cancer
  • Specific tests for infectious diseases like tick-borne diseases
  • Urinalysis to detect infections, bleeding (hematuria) or protein loss

Treatment Options for Thrombocytopenia

It is very important to identify the cause of thrombocytopenia, since different causes have to be treated differently. The treatment depends not only on cause, but also on the severity of the condition.

If the platelet level is very low a platelet transfusion can be done. However, transfused platelets don’t last very long.

If the dog is affected by infections, antibiotics would be prescribed. Tetracyclines  are known to be effective against rickettsia, which is a bacterial agent  that may trigger thrombocytopenia  as well.

For immune-mediated thrombocytopenia, you may use corticosteroids combined with other immuno-suppressive drugs.

The treatment of cancer generated thrombocytopenia will depend on the type of cancer and its location.