Heaves in Horses & Respiratory HealthBy: Dr. Lydia Gray
Recurrent Airway Obstruction (RAO) is the preferred term by veterinarians for what is commonly referred to as “heaves.” In the past, it has also been referred to as COPD or Chronic Obstructive Pulmonary Disease but experts now recognize that this respiratory condition in humans is not the same as the one in horses.
RAO is defined as episodes of obstructive lower airway disease in horses triggered by exposure to hay and bedding and characterized by: difficulty breathing, severe airway inflammation, a large number of neutrophils (white blood cells), airway hyper-reactivity, and reversibility with bronchodilator treatment. Signs include:
- Labored breathing
- Flared nostrils at rest
- Nasal discharge
- Elevated respiratory rate at rest
- Exercise intolerance or poor performance
- “Heave line” (abnormal abdominal muscle development caused by coughing and labored breathing)
“Heaves” can usually be diagnosed based on the horse’s medical history and a physical examination. However, additional tests to rule out other conditions or monitor the horse’s response to treatment may be needed. These include:
- Bronchoalveolar lavage (BAL)
- Blood gas measurement
- Chest x-rays
- Lung biopsy
- Lung function tests
1) prescription medications
Corticosteroids—which reduce airway inflammation—include dexamethasone and prednisolone or the newer beclomethasone and fluticasone. The most common bronchodilators—which relieve airway obstruction--are in the beta-adrenergic agonist family and include clenbuterol and albuterol.
There is good evidence that some herbal supplements may be beneficial to horses with “heaves.” Because the condition may place them under additional oxidative stress, antioxidants are recommended. Vitamin C in particular is being investigated for its role in neutralizing the free radicals associated with “heaves.”
DietDust and mold in hay seem to the best worst offenders to a horse with “heaves,” so steaming or soaking hay—or feeding hay cubes—is often recommended. Completely replacing hay with another fiber source such as a complete feed is an additional alternative.
HousingFor horses with “heaves” that live inside, good ventilation is vital, especially in the winter when most barns are closed up. If they must be stalled, dust-free bedding should be used such as specially treated wood shavings, shredded paper or cardboard, peat moss, or other materials. Straw is a particularly poor type of bedding for these horses. Ideally, horses with “heaves” should be turned out as much as possible.
- Can I continue to ride and show my horse if he has “heaves”?
- How long will my horse have to be on steroids and bronchodilators?
- Will this condition continue to worsen?