What is Anemia in Dogs?

Anemia is a serious hematologic disorder in dogs characterized by a decreased red blood cell (RBC) count, hemoglobin concentration, or both. Since RBCs are responsible for oxygen transport throughout the body, anemia can result in tissue hypoxia, fatigue, and systemic complications if left untreated.

It is important to note that anemia is not a disease itself but a clinical manifestation of an underlying condition. Timely diagnosis and intervention are critical to improving patient outcomes.

For a more in-depth discussion of anemia, refer to the Merck Veterinary Manual.

Clinical Signs of Anemia in Dogs

The clinical presentation of anemia in dogs depends on its severity, chronicity, and underlying etiology. Some of the most common signs include:

  • Lethargy and exercise intolerance – Dogs with anemia often exhibit weakness, reluctance to exercise, and increased fatigue.
  • Pale or icteric mucous membranes – Normal canine gums should be pink; pale or white gums suggest anemia, whereas jaundiced (yellow) mucosa may indicate hemolytic disease.
  • Tachycardia and tachypnea – The body compensates for reduced oxygen delivery by increasing heart and respiratory rates.
  • Dark, tarry stool (melena) or hematochezia – May indicate gastrointestinal hemorrhage, a common cause of blood loss anemia.
  • Pica (ingestion of non-food substances) – Some anemic dogs exhibit abnormal eating behaviors, including soil ingestion, which may be linked to iron deficiency.

Any dog exhibiting these signs requires immediate veterinary evaluation to determine the cause of anemia and initiate appropriate treatment.

Pathophysiology and Causes of Canine Anemia

Anemia in dogs is broadly classified into three primary categories based on its pathophysiology:

1. Hemorrhagic (Blood Loss) Anemia

This type of anemia occurs due to acute or chronic blood loss. Common causes include:

  • Trauma or surgical complications – External or internal hemorrhage.
  • Gastrointestinal ulcers – Induced by NSAID use, neoplasia, or systemic disease.
  • Parasitic infestations – Severe flea, tick, or hookworm infestations can cause chronic anemia.
  • Coagulopathies – Hemostatic disorders (e.g., rodenticide toxicity, thrombocytopenia) lead to prolonged bleeding episodes.

For more information, review the Merck Vet Manual on flea-induced anemia.

2. Hemolytic Anemia (Increased RBC Destruction)

This occurs when red blood cells are prematurely destroyed by intrinsic or extrinsic factors. Common causes include:

  • Immune-Mediated Hemolytic Anemia (IMHA) – A severe immune disorder in which the body attacks its own RBCs.
  • Infectious diseases – Babesiosis, Ehrlichiosis, and Leptospirosis can induce immune-mediated destruction of RBCs.
  • Oxidative damage – Onion, garlic, zinc, or acetaminophen toxicity can lead to Heinz body anemia and hemolysis.

Learn more about IMHA management.

3. Non-Regenerative Anemia (Bone Marrow Suppression or Chronic Disease)

This occurs when the bone marrow fails to produce adequate RBCs. Causes include:

  • Chronic kidney disease (CKD) – Deficient erythropoietin production results in inadequate erythropoiesis.
  • Bone marrow neoplasia or myelodysplasia – Leukemia and lymphoma can infiltrate and suppress normal hematopoiesis.
  • Endocrinopathies – Hypothyroidism and hypoadrenocorticism can contribute to non-regenerative anemia.
  • Iron, folate, or cobalamin deficiencies – Dietary imbalances or malabsorption syndromes can cause nutritional anemia, although rare in dogs.

Diagnostic Approach to Canine Anemia

1. Laboratory Testing

A comprehensive workup is necessary to determine the underlying etiology of anemia. Standard diagnostics include:

  • Complete Blood Count (CBC) – Assesses hematocrit (PCV), RBC count, hemoglobin levels, and reticulocyte count to determine anemia severity and regenerative response.
  • Blood Smear Examination – Detects spherocytosis, Heinz bodies, and RBC parasites.
  • Serum Biochemistry & Urinalysis – Evaluates kidney and liver function, detects hemolysis (e.g., hyperbilirubinemia).
  • Coagulation Panel – Identifies clotting disorders and DIC (disseminated intravascular coagulation).
  • Bone Marrow Aspiration/Biopsy – Necessary for suspected bone marrow failure syndromes.

2. Imaging & Additional Diagnostics

  • Thoracic and Abdominal Radiographs – Identify neoplastic disease, splenic abnormalities, or internal bleeding.
  • Ultrasound-Guided Fine Needle Aspirates (FNA) – Used for tumor staging and aspiration of hematomas.

Read more about blood transfusions in anemic dogs.

Treatment Strategies for Anemia in Dogs

1. Blood Transfusions

Severe anemia (PCV <15-20%) often necessitates blood transfusion therapy to stabilize the patient. Available options include:

  • Whole blood transfusions – Used in cases of acute hemorrhage or severe anemia.
  • Packed red blood cells (pRBCs) – Preferred for chronic anemia to restore oxygen-carrying capacity.
  • Plasma transfusions – Administered in coagulopathies or immune-mediated diseases.

2. Immunosuppressive Therapy

For IMHA and autoimmune hemolysis, treatment includes:

  • Corticosteroids (Prednisone, Dexamethasone) – First-line therapy to reduce RBC destruction.
  • Adjunctive Immunosuppressants (Azathioprine, Cyclosporine, Mycophenolate) – Used in steroid-resistant cases.

3. Treating the Underlying Disease

  • Deworming & Flea Control – Prevents parasite-induced anemia.
  • Iron & Vitamin Supplementation – For documented iron-deficiency anemia.
  • Surgical Removal of Tumors – Indicated for neoplastic causes of anemia.

Prognosis & Long-Term Management

  • Regenerative anemia (e.g., IMHA, blood loss) often has a favorable prognosis with early intervention.
  • Non-regenerative anemia (e.g., CKD, bone marrow disorders) often requires lifelong management.

Routine hematologic monitoring and early intervention significantly improve outcomes.

Schedule a consultation with The Vale Veterinary Group for comprehensive anemia evaluation and treatment.

Anemia is a complex condition requiring a tailored, multidisciplinary approach. Identifying the underlying cause, implementing targeted treatment, and ensuring long-term management are essential to improving canine patient outcomes.

For specialized diagnostics and treatment, contact The Vale Veterinary Group today.