Case Report: Diode laser fenestration for treating conchal malformation in a miniature pony

Chronic unilateral nasal discharge in miniature horses is often caused by dental disease, infection, or anatomical abnormalities. Miniature breeds may be predisposed to sino-nasal obstruction due to disproportionately large teeth and retained juvenile cranial features, which can impair sinus drainage. Congenital or developmental sino-nasal malformations are rarely reported in equids.

A one-year-old Shetland pony filly presented with an eight-week history of unilateral nasal discharge unresponsive to antimicrobial therapy. Endoscopy revealed a displaced dorsal concha overlapping a hypoplastic ventral concha, with malformed drainage pathways. Computed tomography confirmed marked right-sided sino-nasal anatomical abnormalities, including dorsal concha enlargement, ventral concha hypoplasia, and septal deviation.

The filly was bright and alert, with right-sided purulent nasal discharge. Bloodwork revealed mild anemia, lymphopenia, and elevated inflammatory markers. Guttural pouch lavage grew Streptococcus equi subsp. zooepidemicus, while dental examination was unremarkable.

Conservative therapy with meloxicam and doxycycline was unsuccessful. Under standing sedation, diode laser fenestration of the dorsal concha was performed, creating a 3 cm drainage window to restore sinus communication and allow transnasal lavage. Postoperative endoscopy confirmed a patent fenestration with reduced mucosal inflammation. The filly showed rapid clinical improvement and was discharged 6 days later. At a follow-up examination 14 months after surgery, the pony was free of purulent nasal discharge and the owners reported improved activity and quality of life. Endoscopy showed that the fenestration had closed by scar formation, while the nasomaxillary aperture was accessible and the drainage angle appeared normal, consistent with continued growth of the skull.

Congenital or developmental conchal malformations should be considered in miniature horses with chronic unilateral nasal discharge. Advanced imaging, particularly CT, is crucial for diagnosis and surgical planning. Transendoscopic diode laser fenestration is a minimally invasive option to restore sinus drainage and to enable repeated lavage. In this growing pony the fenestration closed over time, while physiological drainage was re-established as the sino-nasal anatomy matured, suggesting that temporary drainage may be sufficient to interrupt the cycle of chronic sinusitis in selected cases.