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Treating Chronic Equine Sinusitis Without Surgery: The Power of Transnasal Sinoscopy
- Nick Moore DVM
- Feb 8
- 2 min read
Chronic sinusitis is a common and often stubborn problem in horses. Despite repeated courses of antibiotics, sinus flushes, tooth extraction, or even sinus flap surgery, resolution can be slow or incomplete.
So why do so many cases fail to improve? The answer often lies in what we can’t adequately see or access using conventional methods.
Why Standard Treatments Often Fall Short
In chronic sinusitis cases, the sinus cavities are frequently filled with thick, inspissated purulent material. This material becomes densely packed and adherent to the sinus walls, making it nearly impossible to fully remove with antibiotics alone or blind lavage techniques.
Even when the primary dental issue is addressed, residual infection and debris can persist within the sinuses. In some cases, surgical approaches such as sinus flaps may still leave pockets that are difficult to access, prolonging healing time and increasing the risk of complications.
Seeing the Real Problem: Endoscopic Visualization
Transnasal sinoscopy changes the game by allowing direct visualization of the sinus cavities. Using endoscopy, veterinarians can clearly see the severity of the infection understanding why previous treatment failed. Thick pus is layered throughout the sinus and sometimes food debris is found which, unless removed, will keep the infection from resolving.
This approach allows for:
Targeted, thorough lavage of affected sinuses
Visualization of areas that are otherwise unreachable
Confirmation of treatment effectiveness in real time
In the case demonstrated, extensive purulent material was successfully removed from the caudal and rostral maxillary using endoscopic guidance, something that would be nearly impossible with conventional methods alone.
Radiographic Improvement Without Surgical Trauma
Pre-operative radiographs in chronic sinusitis cases often show diffuse soft-tissue opacity where air should be present. Following endoscopically guided sinus lavage, post-procedure radiographs reveal marked improvement, with darker, air-filled areas returning - despite some remaining fluid from the lavage itself.
The key benefit?
 No surgical openings. No sinus flaps. Minimal downtime.
Horses can often return to work quickly, which is a major advantage for both horses and owners.
Addressing the Root Cause
While transnasal sinoscopy effectively treats the sinus infection, it’s still critical to address the primary dental pathology contributing to the problem. However, this case illustrates an important principle: Treating the dental issue alone, without addressing the sinus disease, often leads to treatment failure.
Endoscopy allows veterinarians to fully resolve the sinus component before or alongside dental intervention, dramatically improving long-term outcomes.
This diagnostic-first, visualization-based approach is foundational to how we teach equine dentistry at Moore Equine Education.
A Skill Worth Learning
Transnasal sinoscopy is a highly effective, minimally invasive technique—but it does require:
Proper equipment
Technical training
Practice and familiarity with sinus anatomy
As awareness grows, more veterinarians are recognizing that many sinusitis cases can be managed non-surgically, reducing complications and improving patient welfare.
If chronic sinusitis cases are showing up regularly in your practice, better visualization and diagnostics are where real progress begins.
At Moore Equine Education, our training begins with building that foundation.
Start with Occlusal Equilibration & Diagnostics – Module 1, where veterinarians learn how to properly evaluate the equine mouth, understand occlusion, interpret imaging, and identify dental pathology that directly contributes to sinus disease.
From there, our advanced modules build toward more complex diagnostic and treatment techniques - including minimally invasive approaches to sinus disease.
