In anemia in pets, the number of red blood cells (RBCs) or the amount of hemoglobin in the body is reduced.  Hemoglobin is a protein in the RBCs that transports oxygen to cells of the body.  Anemia usually results from another disease process that does one of the following:

• causes blood loss or hemorrhage
• increases the breakdown or destruction of the RBCs
• decreases the production of RBCs

Many conditions can result in anemia through one of these three mechanisms, including parasitism, cancer, immune diseases, chemical or drug toxicity, diseases that affect blood clotting, chronic diseases of any type, poor nutrition, hypothyroidism, and infection with feline leukemia virus (FeLV) or feline immunodeficiency virus (FIV).  Anemia caused by iron deficiency is not common in dogs and cats.

Signs of anemia in pets include pale or white gums and whites of the eyes.  Anemic dogs and cats are frequently weak and lethargic.  Other signs depend on the cause of anemia and may include jaundice or blood in the feces or urine.

A full diagnostic evaluation is important to identify the underlying disease that is causing the anemia.  Diagnostic tests used to characterize the anemia include complete blood counts and hemoglobin levels, serum chemistry profiles, urinalyses, fecal exams, and testing for FeLV and FIV in cats.  It is important to assess whether or not the bone marrow is producing new RBCs to replace those that are being lost, and your veterinarian may recommend a bone marrow biopsy.

Treatment depends on the underlying disease process.  If the anemia is severe, blood transfusions may be needed as a support measure.

Q&A

What is anemia?

Anemia is a reduction in circulating red blood cells, so that the tissues of the body do not get enough oxygen.

What causes anemia in pets?

Anemia can be caused by (1) internal or external bleeding, (2) destruction of red blood cells, or (3) decreased production of red blood cells.  Diseases that can cause anemia through one of these three mechanisms include parasitism, cancer, immune disease, chemical or drug toxicity, poor nutrition, diseases that affect blood clotting, and chronic diseases of any type. 

How is anemia diagnosed in pets?

Your veterinarian can diagnose anemia by measuring the number of red blood cells within a sample of your pet’s blood. 

Written and reviewed by John A. Bukowski, DVM, MPH, PhD
and Susan E. Aiello, DVM, ELS