Bronchoalveolar Lavage (BAL) in Horses
What is Bronchoalveolar Lavage (BAL)?
Bronchoalveolar Lavage (BAL) is a minimally invasive diagnostic procedure used to collect fluid samples from the lower airways of the lungs. It is a vital tool in diagnosing a wide range of equine respiratory conditions, including inflammatory airway disease (IAD), equine asthma (formerly known as RAO or heaves), infections, and allergic airway disorders.
Why Perform a BAL?
When a horse presents with signs such as chronic coughing, nasal discharge, poor performance, or labored breathing, a BAL helps us understand the nature of inflammation or infection deep within the lungs. Unlike tracheal wash, which samples secretions from the upper airways, BAL provides a more accurate picture of the lung environment.
How is the Procedure Performed?
The procedure is typically performed under light sedation to ensure the horse’s comfort. A sterile tube or endoscope is gently passed through the nasal passage and into the lower airways. Once in position, a small amount of sterile saline is infused into the lungs and then immediately aspirated. The retrieved fluid is then sent for cytological analysis, and in some cases, bacterial or fungal cultures.
What Can BAL Tell Us?
BAL fluid analysis allows us to:
- Assess the type and severity of inflammation
- Identify infectious organisms such as bacteria or fungi
- Detect allergic or environmental causes of respiratory issues
- Monitor response to therapy in chronic cases
Is BAL Safe?
Yes, BAL is a safe and well-tolerated procedure when performed by experienced veterinary professionals. Most horses recover quickly and can return to their normal routine shortly after the procedure.
When is BAL Recommended?
Your veterinarian may recommend a BAL if your horse shows:
- Chronic or intermittent coughing
- Poor performance without obvious cause
- Signs of respiratory distress
- Recurring nasal discharge or wheezing
- Poor response to previous respiratory treatments
At our equine hospital, we use BAL in conjunction with a thorough physical examination, endoscopy, imaging (such as radiography or ultrasound), and laboratory tests to arrive at an accurate diagnosis and tailor an effective treatment plan.
