Anemia in dogs refers to a decrease in the number of red blood cells in the blood. Though often mistaken for a disease, it is actually a symptom of an underlying issue. Clinically, it presents as pale mucous membranes, such as the gums and conjunctiva of the eyes. In severe cases, the dog may exhibit weakness and breathing difficulties due to reduced oxygen delivery to tissues and organs.

Red Blood Cell Production

In adult dogs, blood cells are primarily produced in the bone marrow. Immature cells develop into various blood cell types, including red blood cells, which are released into the bloodstream once they mature.

Causes of Anemia

Anemia can result from multiple factors affecting red blood cell production or destruction. It may be caused by:

• Decreased production in the bone marrow
• Increased red blood cell destruction (hemolysis)
• Excessive blood loss due to hemorrhage

Differentiating Types of Anemia

Once anemia is detected via blood analysis, identifying its cause is crucial. The first step is to determine whether it is regenerative or non-regenerative.

• Regenerative anemia: The bone marrow responds by producing new red blood cells.
• Non-regenerative anemia: The bone marrow is failing or not producing enough red blood cells.

Diagnostic Tests

To pinpoint the origin of anemia, several tests can be performed:

• Blood smear: Assesses the shape and size of red blood cells under a microscope.
• Bone marrow analysis: Recommended if other tests fail to reveal the cause.
• Specific tests: May include urinalysis, imaging (X-rays, ultrasound), and coagulation tests.

Regenerative Anemia: Hemorrhage or Hemolysis?

If regenerative anemia is confirmed, it may be due to bleeding or excessive destruction of red blood cells.

• Hemorrhage: Can be internal (organ rupture, tumors, ulcers) or external (trauma, parasites like fleas or ticks). Imaging and clotting tests are often needed.
• Hemolysis: If red blood cells are destroyed by the immune system, it is called immune-mediated anemia. This may be primary (idiopathic) or secondary to infection, medication, vaccines, or cancer.

Non-Regenerative Anemia: Insufficient Production

Non-regenerative anemia may result from:

• Chronic inflammation
• Kidney failure
• Hypothyroidism
• Bone marrow disorders

In severe cases, in-depth blood testing and bone marrow biopsy may be required.

The Role of Bilirubin

During hemolysis, bilirubin—a pigment from the breakdown of red blood cells—can accumulate and cause dark yellow urine. Elevated bilirubin levels are also common in liver disease or bile duct obstruction.

Anemia in dogs is a complex symptom with many potential causes. Accurate diagnosis requires thorough blood analysis and complementary tests. Careful monitoring is essential to identify the underlying cause and tailor the treatment accordingly.