Heaves, also known as recurrent airway obstruction (RAO), is a chronic respiratory disease that affects horses. It is similar to asthma in humans and causes inflammation, mucus production, and bronchospasm in a horse's airways. Heaves is a common condition, especially in older horses, and can negatively impact a horse's performance and quality of life if left untreated. In this blog post, we will discuss the causes, symptoms, diagnosis, and treatment options for heaves in horses.
Causes of Heaves in Horses
Heaves is caused by an allergic or hypersensitivity reaction to inhaled particles such as mold, dust, and pollen in a horse's environment. It is not caused by infection. Horses with heaves develop chronic inflammation in their airways when exposed to these allergens over time. Some factors that can increase a horse's risk of developing heaves include:
Age - Older horses are more likely to have heaves
Genetics - Inheritable factors may play a role
Stabling - Horses kept predominantly in barns are at higher risk
Climate - Hot, humid environments promote mold and dust
Hay - Dusty, poor quality hay may trigger reactions
Symptoms of Heaves
The most common symptoms of heaves in horses include:
Coughing, especially at night or during exercise
Increased breathing effort and flared nostrils
Breathing sounds like wheezing or whistling
Lethargy, exercise intolerance
Horses may show worse signs when stabled and improve when turned out. Mild cases may only exhibit poor performance. Severe cases involve labored breathing even at rest.
Veterinarians use a combination of a physical exam, medical history, and specialized tests to diagnose heaves. They will likely use a stethoscope to listen for wheezing or whistling lung sounds. Other diagnostic tools include:
Endoscopy - Allows visual examination of airway inflammation
Bronchoalveolar lavage - Fluid sampling to check for inflammatory cells
Lung function testing
Allergy testing - Identifies specific allergies
Treatment for Heaves
While there is no cure for heaves, treatment can help control symptoms and allow horses to lead relatively normal lives. Keys to managing heaves include:
Avoiding dust and allergens in the horse's environment through pasture turnout, wetting hay, low dust bedding, well-ventilated barns, etc.
Medications - Bronchodilators open airways while corticosteroids reduce inflammation
Nebulization - Delivers medications via mist inhaled into the lungs
Supplements - Some supplements may reduce airway inflammation
With proper management and treatment, most horses with heaves can be successfully controlled and ridden and worked lightly. However, acute flareups are possible. Veterinary guidance is important for developing an effective treatment plan for any horse diagnosed with heaves.
In summary, heaves is a chronic respiratory disease triggered by inhaled allergens and leading to significant airway inflammation and obstruction in horses. While incurable, heaves can often be well-controlled with environmental management, medications, and veterinary oversight. Horse owners should be alert for signs of the condition, especially in older horses, and work with their vet to protect their horse's respiratory health.