EIPH and Omega-3


Omega-3 fish oil is perhaps one of the most researched substances in modern medicine. Out of more than 20,000 clinical trials the majority of these studies have dealt with omega-3’s action on the cardiovascular system.

Because these polyunsaturated long-chained fatty acids have anti-inflammatory, anti-arrhythmic, antihypertensive effects and enhance blood fluidity, omega-3 substances work well with common heart medications. In human medicine, omega-3 fish oil has been used in conjunction with many different types of medications. There have not been any reported negative interactions. Fish oil supplementation is now endorsed by the American Heart Association, the FDA, the US government and the World Health Organization.

EIPH and Lasix Treatments in Thoroughbred Racing Horses

Sixty percent of all racing horses experience Exercise-Induced Pulmonary Hemorrhage (EIPH). The severity of EIPH significantly decreases a horse’s likelihood of winning.

Furosemide (Lasix) was introduced into the equine industry many years ago as a prophylaxis of EIPH. This was based on the diuretic’s general blood pressure-lowering effect in horses, as many thought that EIPH was a result of increased pulmonary vascular pressure during exercise.

Its popularity became immense since the horses recorded faster running times. However, the reason for this effect is still questioned. Is it due to reduction in body weight or diminished subclinical amounts of mucus and bronchial bleeding?

However, if EIPH is initiated by an acute bronchial inflammation reaction, creating a negative interstitial fluid pressure followed by a leak of mucus and blood into the lungs, another preventive measure would be to lower the inflammation process.

By itself “accumulation of airway mucus is common in young racehorses. The result of several studies suggest that the prevalence of tracheal mucus accumulation and inflammation in racehorses approaches 33%, and moderate to severe amounts of mucus may cause poor racing performance.

Can a safe and potent substance such as fish oil obtain the same effects as Lasix, or be its perfect synergy substance?

Unfortunately, at this time we can only rely on research done in other mammals and make inferences about the effects of omega-3 with regards to EIPH. But it is fascinating to note that omega-3 fish oil could attack the EIPH mechanism through at least 3 different actions:

  1. Peripheral vasodilatation
  2. Anti-inflammation
  3. Improved immunity system

Omega-3 Research

Research has shown fish oil reduces exercise-induced asthma in human. Fish oil also lowers the body’s vascular inflammatory levels and can strengthen the immune system, making it more likely for horses not to respond with bronchial mucus to allergens or other irritants.

A study from the University of Kentucky showed that horses supplemented with fish oil had a lower heart rate during exercise, which may be significant in correcting the EIPH pathogenesis.
Another study from the University of Texas showed that horses supplemented with omega-3 had lower cortisol levels under exercise, making the horses less stressed and maybe also having lower blood pressure.

Numerous clinical studies have shown that fish oil has a unique ability to work in synergy with diuretics, anti-hypertension medications and statins, but it is also a potent cardiovascular substance in its own right. Synergistic dietary therapy with omega-3 EPA and DHA supplementation should help to lower the drug doses and hence minimize side effects of prescription drugs. In addition omega-3 is classified as GRAS (Generally Recognized As Safe) substance so it is safe and easy to use.

Wellpride Pilot Studies on EIPH horses

We have performed our own pilot studies with tracheobronchosocpi examinations before and after 8 weeks of treatments with omega-3 fish oil. There are strong indications that fish oil will work both in conjunction with Lasix for horses with EIPH and even replace or lower the need for Lasix over time.

Hypothetically, from research done on other mammals, omega-3 fish oil is likely to lower the incidents of EIPH by reducing blood pressure levels and heart rate. It may also increase pulmonary vasodilatation and reduce bronchial irritation/inflammation.

Wellpride’s success at the racing tracks from Breeder’s cup to Calder clearly indicates fish oil has a wonderful effect on racing and other performance horses. But a precise medical explanation of fish oil’s positive effects needs to be further investigated.

At the AAEP convention in Orlando, December 2007 the participants were told that a new university study will be published this year, finding that fish oil may indeed prevent EIPH.


1. Hinchcliff k w et al: Association of exercise-induced pulmonary hemorrhage and performance in racing thoroughbred horses. In: AAEP proceedings /Vol 50/ 2004

2. Woie K et al: the relationship between interstial fluid pressure and volume in rat trachea. In Acta Physiologica Scandinavica, Vol 156, pp. 69 (1996)

3. Holcombe s j et al: Tracheal mucus is associated with poor racing performance in thoroughbred horses. In: AAEP proceedings/ Vol. 50/ 2004

4. Mickleborough t.d. et al: Fish oil supplementation reduces severity of excercise-induced bronchoconstriction in elite athletes, Am. J of Resp and Critical Care Medicine. Vol 168. pp.1181-1189 (2003)

5. Lopez-Garcia E et al: Consumption of omega 3 fatty acids is related to plasma biomarkers of inflammation and endothelial activation in women. In: J Nut. 2004 Jul;134(7):1806-11

6. O’Connor C I et al: The effect of dietary fish oil supplementation on exercising horses. In J of Animal Science.2004. 82:2978-2984

Cited by Ott, E Department of Animal Science, University of Florida, EC Magazine winter 2003