Pet Factsheets

Thrombocytopaenia (decreased platelet count)

©VetFolio LLC and Vetstream Ltd. Created and peer-reviewed by VetFolio LLC and Vetstream Ltd.

Thrombocytopenia (a decrease in the number of platelets) is a life-threatening condition. The success of treatment depends on the primary disease and response to treatment.

What is thrombocytopaenia (decreased platelet count)?

Thrombocytopaenia is the term used when a patient does not have enough platelets in the blood. Platelets (also called thrombocytes) are cell fragments that are necessary for forming blood clots and help in repairing damaged blood vessels. Their numbers can be low if not enough are being made in the bone marrow or if too many are being used or destroyed by the body.

If platelet numbers are too low, uncontrolled bleeding can occur, and if treatment is unsuccessful, the patient will die from overwhelming blood loss.

What are the signs of thrombocytopaenia?

The signs of  thrombocytopaenia are:

  • Small bloody spots seen on the skin or gums
  • Bleeding from the nose
  • Blood in vomit, stool, or urine
  • Excessive bleeding from a wound
  • Pale gums
  • Lethargy, weakness

What causes thrombocytopaenia?

Causes of thrombocytopenia include blood loss, immune system disorders, clotting disorders, cancer, and infectious diseases such as Rocky Mountain spotted fever and feline leukaemia virus.

How will my vet diagnose thrombocytopaenia?

Thrombocytopaenia is diagnosed based on history, clinical signs, physical examination findings, and laboratory tests. A platelet count is included in a complete blood count (CBC). Other tests may be performed to determine what is causing the low platelet numbers. These may include a blood chemistry panel, urinalysis, radiography (x-rays), ultrasound, tests for immune diseases, tests for infectious disease, and bone marrow sampling.

How is thrombocytopaenia treated?

Thrombocytopaenia needs to be treated as soon as it is recognised. As many of the illnesses that cause thrombocytopaenia are not obvious right away, your vet may choose to start treatment for the most common causes before knowing the exact one. Initial treatments may include blood or plasma transfusions, steroids, and antibiotics. As the diagnosis becomes clear, your vet may customise treatment. Some patients may need to be medicated for months to years until their platelet numbers stabilise. Follow-up care for these patients consists of frequent physical examinations and platelet counts. Medications may be slowly discontinued after platelet numbers have been in the normal range for some time; however, relapses occur in about 50% of cases, and some pets may not respond to treatment.

How can thrombocytopaenia be prevented?

There is no known way to prevent thrombocytopenia, but the use of the feline leukaemia vaccine (in cats) and a solid tick prevention strategy may help in the prevention of infectious diseases that can cause thrombocytopaenia. Avoiding the original cause may minimise relapses.