The truth about blood builders
A blood builder can aid in preventing a horse from getting anemia and also in improving athletic


Regardless of what a horse’s primary job is, maintaining its health should be the primary focus of all owners and trainers. Whether a horse races, ranches or travels on trails, its duties would be impossible to perform if it is not in peak condition.Many people who work with equines have used products known as “blood builders” in their efforts to optimize not only a horse’s health, but its performance as well. A blood builder is an industry term for a dietary supplement comprised primarily of iron; however, each one generally features additional nutrients such as cobalt, riboflavin and vitamins B, A and C.  These are often referred to as hematinics—nutrients needed for red blood cell formation—and used primarily to fight the condition known as iron-deficiency anemia or to improve a horse’s abilities during vigorous exercise.

While a blood builder does have inherent benefits when introduced into a horse’s diet, some believe it can be used as a magic cure-all additive to instantly heal an ailing horse or allow it to jump higher and run faster, which is not the case. There are misconceptions about the supplement’s effects and usage of which owners and trainers should be aware.

The basics of red blood cells and iron’s presence in the body

In order to know when and how blood builders work, it is important to understand how red blood cells work within the body and their relationship with iron.

The Merck Veterinary Manual details how red blood cells, also called erythrocytes, function primarily to deliver oxygen from the lungs to cells throughout the body. Cells use the oxygen as a form of energy needed for bodily functions to occur, especially exercise. The oxygen attaches itself to molecules called hemoglobin, which are proteins that carry the iron within red blood cells. The waste product, carbon dioxide, is then carried from cells to the lungs where it is exhaled.

The Merck Veterinary Manual {had to change source since original concluded that blood builders were dangerous or a waste} states that red blood cells have a limited lifespan so destruction and regeneration is an ongoing process. The number of red blood cells remains constant in a healthy horse, and deviations can lead to disease. According to research from Finish Line Horse Products, it takes approximately six weeks for red blood cells to mature in a healthy horse. The spleen then destroys old blood cells but reuses the iron inside the hemoglobin to make new ones. The recycling and creation of red blood cells is dependent upon a continuous supply of certain essential nutrients and hormones. One hormone vital to this process is Erythropoietin, a substance produced in the kidneys that prompts stem cells within bone marrow to create new red blood cells. Iron along with other minerals and vitamins such as cobalt, B12, folic acid and riboflavin are necessary in the manufacture of red blood cells.

Iron is a critical component in the creation of red blood cells and in the distribution of oxygen throughout a horse’s body.

Red blood cells, iron and performance

“A blood builder is most essentially used for increasing the flow of oxygen.”

Red blood cells account for 35 percent of a horse’s total blood volume when it’s at rest. However, that percentage almost doubles during intense periods of physical activity, according to Trainer Magazine. The spleen houses around 50 percent of the body’s red blood cell count. This organ saves the cells, which carry oxygen, until they are needed by the muscles engaged in work. Cells are then squeezed from the spleen and delivered to muscles at a rate that matches the energy needed to guarantee optimum effectiveness.

During exercise, much of the oxygenated blood already in circulation through the remainder of the body is diverted from internal organs like the kidneys and intestines to the muscles being called upon. A horse’s muscles in these moments can demand oxygen levels up to 35 times more than their resting rate.

The animals already have incredible abilities to intake massive amounts of oxygen. They can transition from only consuming 80 liters of air per minute at rest to upwards of 1,800 liters during a fast gallop.

Iron Loss and Intake

It is important to remember that the overwhelming majority of a horse’s athletic ability depends the state of its cardiovascular and muscular development – not how many red blood cells it is able to store, create and relocate. However, there is iron present in sweat which means that some iron is lost during bouts of exercise. Iron can also be lost due to parasites or bleeding, such as from an injury, exercise-induced pulmonary hemorrhage or gastric ulceration.

According to Kentucky Equine Research, a horse produces 25 to 30 liters of sweat per day when performing vigorous activity. Iron concentrations within the sweat are estimated to be around 21 milligrams per liter, or around 500 milligrams each day.

Since iron is necessary for the production of red blood cells and the distribution of oxygen, there is potentially a need for a highly-athletic horse to be supplemented with additional iron through a blood builder. This now begs the question: How much supplementation is necessary?

Horses are generally able to get more than enough iron through standard foraging. Many horse feeds also include enough of the nutrient to supply an active horse adequately. Iron absorption also decreases as iron intake increases; the more iron there is in a horse’s system, the less likely it is to use the nutrient effectively.

It is best to speak to a veterinarian about how much, if any, extra iron would be necessary for an equine based on its specific daily routines, diet and health.

Additionally, an abundance of iron can also make a horse hot or nervous. However, certain B vitamins are expected to keep a horse calm. Finish Line’s Iron Power has all the iron and B vitamins an equine needs to stay healthy and focused. 

“Iron Power contains many nutrients necessary for healthy blood cell development: eight B-vitamins including B12, biotin, folic acid and B2, and minerals including iron, cobalt and copper,” says Nick Cinquino, a Research Chemist at Finish Line® Horse Products.

Broodmares and studs can benefit from high erythrocyte concentrations. Studs can acheive increased sperm counts, mares have a better chance of conception, leading to healthier foals. Horses can gain a level of immunity from diseases as well.

It is possible and quite easy to give a horse too much iron, a situation that could lead to liver failure, especially in young foals, according to Kentucky Equine Research. A horse is more likely to experience issues from over-supplementation of iron versus having their performance adversely affected by low iron levels. 

Blood builders for anemia

Anemia can result from blood loss due to injury and the destruction of blood cells or a dip in their creation. Symptoms, which stem from the fact that oxygen fails to circulate adequately throughout a horse’s body, include fatigue and unusually poor performance, hair loss, weakness, lethargy and loss of appetite, among others.

Although the ailment can be identified by its symptoms, its cause can be more difficult to pinpoint because it is usually the result of a secondary health condition unrelated to an iron deficiency, according to Merck Veterinary Manual. In fact, there has been no recorded case worldwide of a horse falling ill due to a lack of iron. A blood test can measure packed cell volume, which can determine if anemia is present and, if so, to what degree. However, the specific cause cannot be found using this method.

Anemia due to the  destruction of red blood cells can occur via the ingestion of toxins such as red maple  leaves, drugs like phenothiazine tranquilizers or infection. Kidney failure, bone marrow diseases, digestive system problems, parasites and poor nutrition can all decrease a horse’s ability to produce red blood cells, leading to anemia.

Yet an increase in dietary iron content does not boost red blood cell production, according to Kentucky Equine Research. Giving an anemic horse an abundance of iron supplements will not ensure its return to complete health. Anemia could be affecting a horse whose iron levels have been sufficient for some time due to the various other causes that can create the condition. A veterinarian should be consulted if an owner is concerned their horse is anemic and whether iron would be beneficial to them.

“The benefits [of a blood builder] include higher blood counts, increased energy and ability to perform work, as well as a better immune response,” said Steve Blanchard, President of Finish Line® Horse Products.

A blood builder is most essentially used for increasing the flow of oxygen in a horse’s body. An owner or trainer may use it to optimize athletic performance, but the degree of the product’s benefits may be incremental and will largely depend on the horse’s overall fitness. Owners can also use a hematinic in an attempt to counteract an anemic condition, but this effort will depend on what is truly causing the sickness in the first place.



Most Popular: