Diagnosis Diagnostic tests are needed to recognize thrombocytopenia and exclude other diseases. Tests may include:
A complete medical history and physical examination. Your veterinarian will ask about previous vaccinations and drug administration as possible factors in the development of thrombocytopenia.
A complete blood count (CBC or hemogram) including a platelet count to identify thrombocytopenia and anemia that may arise from bleeding
Serum biochemistry tests to evaluate for abnormalities in other organ systems and to evaluate the general health
Urinalysis to evaluate for infection, bleeding (hematuria) or protein loss that may occur as a complicating problem in some causes of thrombocytopenia
X-rays of the chest or abdomen to evaluate for the presence of other diseases such as infections or cancer that may be associated with thrombocytopenia.
Specific tests for infectious diseases, like tick-borne diseases such as Rocky Mountain Spotted Fever or ehrlichiosis.
Bone marrow aspiration to obtain a sample for laboratory analysis if there is concern that your dog's bone marrow may not be making adequate numbers of platelets or may have been invaded by cancer. This procedure often is performed under sedation with a local anesthetic to numb the biopsy site.
Other tests of blood clotting. Body-wide abnormalities in coagulation (disseminated intravascular coagulation) can result in massive consumption of platelets.
Immune system function tests if an immune-mediated disease is suspected. In this case the body fails to recognize the platelets as part of itself and attacks them as if they were foreign invaders. The body may consider the platelets as foreign invaders if they become coated with certain drugs or infectious agents.
Treatment
Treatment for thrombocytopenia depends on the underlying cause of the low platelet count.
Unless your dog is bleeding, only the underlying cause of the thrombocytopenia is be treated. If a specific cause can be treated successfully, the blood platelet concentration soon returns to normal.
Corticosteroids (cortisone-like drugs) are often used to stop the immune system from destroying platelets.
Antibiotics, especially tetracyclines, often are prescribed until specialized test results for infectious disease are available. Tetracycylines are chosen because they are effective against bacterial agents called rickettsia that may cause thrombocytopenia, as in ehrlichiosis and Rocky Mountain spotted fever.
It is difficult to increase platelet numbers adequately by transfusion, and transfused platelets do not last very long – a few days at most. Transfusion of whole blood, which contains plasma and all blood cell types including red blood cells and platelets, or packed red cells, which contains red blood cells without plasma, may be necessary in the event of life-threatening hemorrhage or if your dog is anemic from previous blood loss. Platelet-rich plasma is difficult to prepare and is not widely available for dogs.
Home Care and Prevention
Administer as directed all medications prescribed by your veterinarian. Keep your dog calm and confined indoors to prevent bleeding and bruising. Watch for signs of bleeding or bruising and call your veterinarian immediately if such signs occur or worsen.
Prevent tick bites whenever possible because ticks transmit the bacterial agents (rickettsia) that cause ehrlichiosis and Rocky Mountain spotted fever, diseases that cause thrombocytopenia. Use tick preventives and check your dog daily for ticks during warm weather. Other causes of thrombocytopenia are not preventable.
