A 47-year veteran horse trainer didn’t really pay much attention to how to increase red blood cells in horses.
Although it was a concern since blood tests showed two of his horses had a lower RBC count. The day after a race, they were unusually sluggish, even performed poorly thereafter.
But lo and behold, a blood-building supplement changed his horses’ course. After adding it to their feeding routine, they went on to set new lifetime marks and won races at higher class.
It’s a success story.
But not one everybody shares.
Horse owners, trainers, even vets administer some form of hematinics or blood builders to increase oxygen concentration. The goal: improve performance.
Before you go on jumping tactics on how to increase red blood cells in horses, consider these:
- Is your method effective?
- Is it safe?
- Does it really help your horse’s performance?
Researchers, equine experts and Science have weighed in on these issues. Here are the truths you need to know to help your horse go the distance.
The Truth: Horses are Naturally Blood Dopers

They have a spleen ambitious athletes could only dream of. That means tremendous amounts of red blood cells get stored in this huge spleen that can measure up to 4 feet long, 8 inches wide and 4 inches thick.
When more red blood cells are generated, more oxygen gets ferried into the muscles. After all, muscles require oxygen to perform harder and increase endurance.
More red blood cells= more oxygen = peak performance
If horses have a powerhouse storage of red cells in their spleen, the question remains.
Why is there a Need to Increase Red Blood Cells in Horses?
Blood builders or hematinics have been administered to racing horses for another reason: to treat anemia or increase low red cell count.
Could your Horse Be Anemic?
Most searches on how to increase red blood cells in horses is to treat anemia, a condition in which the blood is deficient in red cells, hemoglobin or total volume. An anemic horse may show symptoms as:
- Poor performance
- Low energy
- Poor appetite
- Hairloss
- Depression

However, experts say both iron deficiency and iron-deficiency anemia are very rare in horses. Especially if they have access to forages and grains from dirt or pasture.
Unless they are locked in stalls and fed poorly. A study from a team of researchers in the Netherlands confirmed horses confined in stalls become listless. Bloodwork showed they were anemic.
Other possible causes of anemia may arise from an infection, blood loss, copper deficiency, allergies and a sedentary lifestyle, among others.
In severe cases, racehorses are given supplementation to boost red cell counts and prevent a fatal anemia.
So instead of learning how to increase red blood cells in horses on your own, how about letting an expert assess your horse’s condition?
Otherwise, if your horse is generally happy and healthy, don’t consider the risk of increasing your runner’s red blood cells thru doping agents such as Erythropoietin (EPO).
Also read: The 7 Most Common Horse Health Problems And the Best Ways to Fix Them
The Risks of Blood Building

EPO is a naturally occurring hormone produced by cells in the kidneys that stimulate red blood cell production.
In Australia, it is illegal to use recombinant EPO for nonmedical purposes.
But in an attempt to enhance performance other hematinics or “blood builders” are used. They can be in various preparations which may include iron, copper, B12, thiamin, riboflavin and folic acid.
But drugs such as EPO doesn’t carry much effect either. Since horses have great reserves of red blood cells in their spleen, their system naturally increases red cell count when needed as in the case of a strenuous race.
“Horses have some protective physiological mechanisms, They can accommodate the huge amount of red cell volume that is squeezed in from the spleen at the onset of exercise,“ says Ken McKeever, PhD, FACSM, professor of equine exercise physiology at Rutgers University.
For horses with normal red blood cell count, research shows these performance enhancers may only place the animal in serious health problems.
The Truth: Blood Builders have more side effects than Benefits
Getting the blood too thick using hematinics have been associated with red cell horses side effects as clotting, heart problems, severe anemia and eventually death.
The takeaway: Using EPO or other harmful red cell vitamins for the purpose of performance enhancement is not a healthy option or a proven effective one.
When Horses Need Red Blood Cell Booster Supplements
You’ve been reading rave reviews about red cell vitamins for horses.
If you do dig deeper you’ll find red cell horse supplement side effects are confined in forums. After all, scientific researches in the field of red blood cell boosters are still in their infancy.
The reality is they could get all the nutrients they need from a healthy diet to ensure the natural production of EPO.
A research from Europe though shows horses can’t meet their vitamin requirement with the lack of forage or high-quality pasture. Thus, for competitive purposes, racehorses are stabled to ensure their nutrient intake. So how do you know if your horse could benefit from a supplement?
The Truth: Horses Need Nutritionists More

Non-racing horses could graze all day. Whereas, thoroughbreds don’t just survive on oats and hay. Just like human athletes, the top runners have nutritionists to ensure the quality of their feeds.
The takeaway: Let an equine nutritionist evaluate your horse’s diet. From there you can have a trusted answer as to whether those extra supplements are needed such as red blood cell boosters.
Read more: The 4 Best Horse Vitamin and Mineral Supplements.
How to Increase Red Blood Cells in Horses: What’s been Tried and Tested So Far
They say great racehorses are born, not made. It’s in the genes.
This doesn’t mean it’s the end of the line for the remaining hundreds to thousands of less-gifted breeds.
There are ways to find that edge, apart from luck.
By far, these are the strategies trainers have tried in a desperate search for a breakthrough.
- Improve Feeding Regimes

This is why the demand for Equine Nutritionists have soared over the last century. Nutrition plays a role in increasing red blood cells production. Not to mention, a horse’s health, welfare, and overall performance.
Certain vitamins and minerals can bolster red blood cell production in horses including Vitamin B-6, Folic Acid, Vitamin B3, Boron, Inositol and Iron.
A thoroughbred usually get their 35,000 calories of energy per day from devouring 8 kilograms of feeds, forage and 50 liters of water. Horses are also fed much like their jockeys and trainers: three times a day.
“We use oats, maize, alfalfa, a lot of soy oil because that’s very energy dense, and a lot of sugar beet pulp, because that’s something that’s quite sweet and that horses like to eat.” Polly Bonner, director of nutrition at Saracen Horse Feeds told CNN.
- Altitude Training has been Promising

Hubert Vieux-Pernon, who breeds racehorses, designed a training facility for racehorses in Alpe d’Huez, France.
He claimed a three-week stay at the 2,000-meter elevated track can increase a horse’s red-cell count by as much as 25 percent.
Some horses complete their training in the mountains. So far, there is evidence that altitude training can prove to be an advantage in increasing the reserves of red blood cells.
Whether this proves to be effective or not, going to new heights in training is better than using drugs or ineffective red blood cell booster supplements.
This makes sense since the heart gets larger and more powerful with training (think of Melbourne cup legends like Phar Lap and Carbine).
Simply put, horses with better aerobic function will be able to perform faster and endure a race in peak performance, much longer.
- Give them a Rest

Thoroughbreds need time to recover from a race. One research shows the repair process is slow in areas of bone repeatedly stressed by high loads such as during a high-intensity training.
A separate study from the Utrecht University in The Netherlands also found overtraining can harm the horse’s heart, musculoskeletal system, and immune system.
A compromised immune system can make horses prone to infection affecting their red blood cell count.
Take it from the retired Kentucky Derby 2016 winner Nyquist. Two weeks after the race, he faltered and ran a fever. His trainer Doug O’Neill knew that rest was in order for the horse to recuperate.
“I’ve learned not to overdo it and just maintain, keeping them happy and healthy,” he says. “They’ll run to their ability,” O’Neill told GQ.
You may also like: Horse Care Tips and Tricks for Beginners
Final Thoughts on How to Increase Red Blood Cells in Horses
Australia’s greatest race, the Melbourne Cup were run by the fastest, the fiercest and horses free from harmful drugs or banned red blood cell booster supplements.
Yes, increasing red blood cells in a horse’s system can boost their gallops but it’s just part of the big picture in the heart-lung-oxygen function. Whatever route you choose to go, safety should always come first. Most importantly respect for such big-hearted, hardworking sprinters.
