Nasal passages
Examination of the nasal passages as part of the upper airway.
Equine Diagnostic Services
Endoscopy & Dynamic Endoscopy
Resting and dynamic airway assessment for racehorses and performance horses experiencing respiratory noise, poor performance or suspected upper airway problems.
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Understanding Endoscopy
Assessing your horse’s airway
Endoscopy allows veterinarians to directly examine the horse’s upper airway and other internal structures using a flexible camera.
At Racetrack Veterinary Services, we provide both resting endoscopy and dynamic endoscopy to investigate respiratory noise, poor performance and suspected upper airway problems in racehorses and performance horses.
Dynamic endoscopy is particularly valuable because some airway abnormalities only occur during exercise and may not be visible when the horse is examined at rest.
When might endoscopy help?
Investigate respiratory noise during exercise.
Assess poor performance or reduced stamina.
Investigate suspected upper airway obstruction.
Assess airway function as part of a suitable pre-purchase or poor-performance investigation.
The Procedure
What is equine endoscopy?
Equine endoscopy involves passing a flexible endoscope through the horse’s nostril to examine structures within the upper airway.
A resting endoscopic examination may allow the veterinarian to assess the:
Pharynx and larynx
Assessment of the pharynx, larynx and structures involved in airflow.
Soft palate and arytenoids
Observation of the soft palate, arytenoid cartilages and vocal folds.
Guttural pouches
Examination of the opening of the guttural pouches.
Trachea
Depending on the clinical problem, endoscopy may also be used to assess the trachea.
Real-time assessment
The procedure gives the veterinarian a real-time view of the airway and can help identify abnormalities that may contribute to respiratory noise, coughing or reduced athletic performance.
When might a horse need endoscopy?
Endoscopy may be recommended if a horse is showing:
- Respiratory noise during exercise
- Poor performance
- Reduced stamina
- Coughing
- Abnormal breathing
- Nasal discharge
- Difficulty swallowing
- Suspected upper airway obstruction
- Abnormal findings during a veterinary examination
- Concerns identified during a Pre-Purchase Examination
It may also be used as part of a racehorse or performance horse assessment where airway function is an important consideration.
Two Types of Examination
Resting endoscopy and dynamic endoscopy
Resting endoscopy
Resting endoscopy is performed while the horse is standing quietly. It allows the veterinarian to assess the structure and function of the upper airway at rest and may identify abnormalities such as:
- Laryngeal asymmetry
- Reduced arytenoid movement
- Inflammation
- Pharyngeal abnormalities
- Soft palate abnormalities
- Abnormal secretions
- Structural changes
Resting endoscopy can provide valuable information, but it does have limitations. Some airway problems only occur when the horse is exercising at speed or breathing under increased pressure. This is where dynamic endoscopy can be particularly useful.
What is dynamic endoscopy?
Dynamic endoscopy allows the horse’s airway to be examined while the horse is exercising.
A lightweight endoscope is secured to the horse, allowing the veterinarian to view and record the upper airway during ridden work or training.
This means the airway can be assessed under conditions that more closely replicate the situation in which the horse is experiencing the problem.
Dynamic endoscopy is particularly useful in racehorses and performance horses with exercise-related respiratory noise or unexplained poor performance.
Exercise-Based Assessment
Why is dynamic endoscopy important?
The upper airway can behave very differently during exercise compared with rest. Some conditions may only become apparent when airflow and respiratory pressures increase at speed.
Dynamic endoscopy can help identify conditions such as:
Dynamic laryngeal collapse
Airway changes that occur during exercise.
Intermittent dorsal displacement of the soft palate
A soft-palate abnormality that may occur intermittently during work.
Aryepiglottic fold collapse
Assessment of collapse involving the aryepiglottic folds.
Pharyngeal collapse
Assessment of pharyngeal function under exercise conditions.
Vocal fold abnormalities
Observation of the vocal folds while the horse is working.
Combined upper airway obstruction
Assessment of complex or combined upper airway obstruction.
Because the abnormality is viewed while the horse is exercising, dynamic endoscopy can provide information that may not be available during a resting examination alone.
For Athletic Horses
Dynamic endoscopy for racehorses and performance horses
Dynamic endoscopy for racehorses
Racetrack Veterinary Services regularly works with racehorses and understands the importance of evaluating airway function under realistic training conditions.
Dynamic endoscopy may be recommended where a racehorse:
- Makes an abnormal respiratory noise at speed
- Fades late in races or gallops
- Performs below expectations
- Shows reduced exercise tolerance
- Has an inconclusive resting endoscopy
- Has a suspected dynamic airway obstruction
Where appropriate, the examination can be performed during the horse’s normal training or exercise routine so that the veterinarian can assess airway function under relevant conditions.
Dynamic endoscopy for performance horses
Dynamic airway problems can also occur in showjumpers, dressage horses, eventers and other performance horses.
In these horses, signs may include:
- Noise during strenuous work
- Loss of performance
- Reduced stamina
- Difficulty maintaining intensity
- Abnormal breathing during exercise
- Changes in performance that cannot be explained by musculoskeletal examination alone
Dynamic endoscopy can help determine whether upper airway function is contributing to the problem.
Broader Veterinary Assessment
Endoscopy as part of a poor performance investigation
Poor performance is often multifactorial. Respiratory problems may occur alongside musculoskeletal, cardiac or other issues.
Depending on the horse, an investigation may include:
- Clinical examination
- Resting endoscopy
- Dynamic endoscopy
- Lameness assessment
- Diagnostic imaging
- Blood tests
- Cardiac assessment
- Other investigations based on clinical findings
Our team of veterinarians can help determine which examinations are most appropriate based on the horse’s history and performance concerns.
Endoscopy during a Pre-Purchase Examination
Endoscopy may also be recommended during a Pre-Purchase Examination, particularly for racehorses and performance horses.
A resting endoscopic examination can help assess the upper airway and identify abnormalities that may be relevant to the horse’s intended athletic use.
If there is concern about a dynamic airway problem, further assessment during exercise may be recommended.
What to Expect
What happens during an endoscopic examination?
During a resting endoscopy
The horse is generally restrained while the flexible endoscope is passed gently through one nostril.
The veterinarian examines the structures of the upper airway and may ask the horse to swallow or perform other manoeuvres to assess movement and function.
The examination is usually relatively quick.
Sedation may sometimes be used depending on the horse and the purpose of the examination, although sedation can influence some aspects of airway function and is therefore considered carefully.
During a dynamic endoscopy
A lightweight endoscope and recording unit are fitted securely to the horse before exercise.
The horse then performs an appropriate level of work, which may include ridden exercise, trackwork or other discipline-specific activity.
The airway is recorded throughout the exercise period.
The veterinarian can then review the footage and assess whether an abnormality occurred during work.
Next Steps
Treatment following endoscopy
Treatment depends on the abnormality identified and its significance. Options may include:
Monitoring
Monitoring where the finding and clinical signs indicate this is appropriate.
Training or management changes
Changes to training or management where recommended by the veterinarian.
Medical treatment
Medical treatment based on the horse’s individual findings.
Specialist assessment
Referral for specialist assessment where required.
Surgical treatment
Surgical treatment may be considered in selected cases.
Not every endoscopic finding requires treatment. The significance of any abnormality should be considered alongside the horse’s clinical signs, intended use and level of performance.
FAQ
Frequently asked questions
What is the difference between resting and dynamic endoscopy?
Resting endoscopy examines the horse’s airway while standing quietly. Dynamic endoscopy examines and records the airway while the horse is exercising.
Why can’t all airway problems be diagnosed at rest?
Some upper airway abnormalities are dynamic, meaning they only occur when the horse is exercising and respiratory pressures increase.
Does dynamic endoscopy hurt the horse?
The procedure is designed to allow the horse to exercise while wearing the equipment. Most horses tolerate it well.
Does my horse need sedation?
Sedation may sometimes be used for resting endoscopy, depending on the horse and the reason for the examination. It is generally not appropriate during dynamic exercise testing.
Can you perform dynamic endoscopy during trackwork?
Where appropriate, yes. Dynamic endoscopy can be performed during exercise so that the airway can be assessed under conditions relevant to the horse’s normal workload.
Is endoscopy useful for poor performance?
Yes. In some horses, poor performance may be associated with an upper airway problem, particularly if there is respiratory noise or reduced exercise tolerance.
Can endoscopy be included in a Pre-Purchase Examination?
Yes. Resting endoscopy may be included where appropriate, particularly for racehorses and performance horses.
Book an Endoscopic Examination
Investigate respiratory noise and poor performance
If your horse is making respiratory noise, struggling during exercise or performing below expectations, endoscopy may help determine whether an upper airway problem is contributing.
Racetrack Veterinary Services provides resting and dynamic endoscopy for racehorses and performance horses, with investigations tailored to the individual horse and its intended workload.
BOOK A VET ☎  03 5975 6586