top of page

The Lifesaver for Bleeding Horses: Furosemide and Its Vital Considerations

Horses are magnificent creatures, known for their grace and power. However, even the strongest of animals can face health issues, including exercise-induced pulmonary hemorrhage (EIPH), commonly referred to as bleeding. One of the go-to treatments for bleeding in horses is the diuretic drug, furosemide. In this article, we will delve into why furosemide is a crucial component in managing bleeding in horses, why it should not be used in conjunction with NSAIDs, and the vital importance of replenishing potassium and other electrolytes following its use.

Understanding Furosemide

Furosemide, often marketed under the brand name Lasix, is a loop diuretic that has proven to be highly effective in treating bleeding in horses. EIPH is a common condition in racehorses and performance horses, characterized by the presence of blood in the airways after strenuous exercise. This condition can compromise a horse's performance and overall well-being, making the management of EIPH essential for both the horse's health and the sport in which they participate.

Why Furosemide Helps Bleeding Horses

  1. Reduces pulmonary congestion: Furosemide works by increasing the excretion of excess fluid and electrolytes from the horse's body, thereby reducing the pulmonary congestion that often accompanies EIPH. This is particularly important, as pulmonary congestion can exacerbate bleeding.

  2. Lowered blood pressure: Furosemide also has the effect of lowering blood pressure. This can reduce the pressure on the blood vessels in the lungs, further minimizing the risk of rupture and bleeding during intense exercise.

  3. Enhanced performance: By managing EIPH, furosemide can help horses perform at their best. This makes it a valuable tool for both horse trainers and owners, as well as ensuring the welfare of the animals.

Avoiding NSAIDs in Conjunction with Furosemide

While furosemide is a highly effective treatment for EIPH, it is important to be cautious when using it in conjunction with non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs, such as phenylbutazone (Bute) and flunixin meglumine (Banamine), are commonly used to alleviate pain and inflammation in horses. However, combining furosemide with NSAIDs can have adverse effects.

  1. Increased risk of kidney damage: Both furosemide and NSAIDs can affect renal function. Using them together may increase the risk of kidney damage, especially when not administered under close veterinary supervision.

  2. Reduced effectiveness of NSAIDs: Furosemide can cause increased urine production, potentially diluting the concentration of NSAIDs in the bloodstream, making them less effective.

  3. Dehydration: Furosemide causes significant fluid loss, and when used with NSAIDs, it can exacerbate dehydration in horses. Dehydration can lead to a range of health issues, including electrolyte imbalances and colic.

Importance of Replenishing Potassium and Other Electrolytes

After administering furosemide to horses, it is crucial to address the electrolyte imbalances it can create, particularly with regard to potassium. Furosemide not only eliminates excess fluids but can also lead to the loss of essential electrolytes. This makes it imperative to replenish these electrolytes to maintain the horse's overall health.

  1. Potassium balance: Maintaining proper potassium levels is vital for muscle function, heart health, and nerve transmission in horses. A deficiency can lead to muscle weakness, cardiac irregularities, and other health problems.

  2. Other electrolytes: Furosemide also affects the levels of sodium, chloride, calcium, and magnesium in the horse's body. Monitoring and replenishing these electrolytes are equally important to prevent related health issues.


Furosemide is a crucial tool in the management of exercise-induced pulmonary hemorrhage in horses, significantly improving their performance and overall well-being. However, it should be used with care, particularly when considering the potential interaction with NSAIDs, which can have adverse effects on a horse's health. Additionally, addressing electrolyte imbalances, especially potassium, following furosemide administration is essential for maintaining the horse's overall health and ensuring they are ready for their next race or performance. By following these guidelines, horse owners and trainers can provide the best care for their equine athletes and companions.

31 views0 comments


bottom of page