Inflammation is typically considered a negative process in horses, and therefore, some horse owners choose to feed their horses supplements to counteract this process, such as spirulina, an edible blue-green algae which is thought to have anti-inflammatory effects.

However, some level of inflammation is needed to help increase bone density, especially in young horses. Without proper bone density, horses are more prone to injuries and poor performance as they age, said Wendy Pearson, PhD, associate professor at the University of Guelph, in Ontario. Ultimately, inflammation is a normal process and necessary result of any activity that will help the horse adapt to future exercise, she said during her presentation at the Equine Science Society’s Symposium, held June 6-9 in Grapevine, Texas. “Increased nitric oxide (a result of inflammation) helps with tissue adaptation and is essential for mitochondrial (the energy source for the cell) function,” Pearson added.

Owners often use spirulina as a top-dressed nutritional supplement for horses due to its anti-inflammatory properties; however, researchers haven’t confirmed whether these types of supplements interfere with tissue’s ability to adapt to exercise, she added. Spirulina is known to decrease systemic inflammation and, therefore, might inhibit this desired inflammatory process.

Pearson and her team designed a study involving a cartilage explant model (in vitro, or in the lab) to simulate the effects of dynamic compression and hypoxia (reduced levels of oxygen in the blood), which would normally occur during exercise in horses and create an inflammatory response.

The researchers took cartilage explants from swine and stimulated them to behave arthritically by introducing lipopolysaccharides (large molecules that are bacterial toxins) and low oxygen to mimic the physiological changes of exercise such as inflammation. They then added the simulation digested product of spirulina, and cultured it for 72 hours until it stabilized.

“Our results showed that spirulina had a possible protective effect on the structure of the cartilage,” said Pearson. “A complete analysis is still needed, and we have an in vivo study coming soon,” meaning the researchers are studying the supplement’s effect in live horses. The researchers expect that this top dressing application will also increase blood flow to the joint which is necessary for improved joint recovery.

For horse owners seeking natural ways to support their animals’ joint health, performance, and exercise recovery, this study points toward spirulina as a potential supplement option to help improve their horses’ soundness and career longevity.