Anemia in Horses
By: Dr. Lydia Gray | Updated March 21, 2025 by SmartPak Equine
Anemia is an insufficient level of healthy red blood cells (RBCs).
Causes and Signs of Anemia in Horses
In horses, anemia is may be caused by:
- chronic inflammation or infection that leads to decreased red blood cell production (most common cause of anemia).
- acute blood loss (such as from an injury).
- chronic blood loss (from ulcers or internal parasites).
- autoimmune diseases or toxins that destroy red blood cells.
Signs of anemia may include:
- pale mucous membranes
- depression
- weakness
- increased heart and respiratory rates
- heart murmur
- decreased performance
- shock
Treatment Options for Anemic Horses
If you suspect your horse may be anemic, contact a veterinarian for a complete physical examination, bloodwork and specific testing to diagnosis the condition and identify common causes.
While these problems are being treated, make sure your horse is on an improved nutritional plan that includes important blood-building ingredients like copper, zinc, cobalt, B-vitamins and others.
Iron Deficiency Anemia
Anemia due to iron deficiency is rare in horses on modern diets, unless there has been significant blood loss. This is because iron from RBCs is "recycled" as the cells reach the end of their normal life span and are taken out of circulation by the spleen. Oversupplementing your horse with iron may interfere with the absorption of other minerals in the diet.