Successful treatment of a sinonasal cryptococcal granuloma in a horse.

This research article documents a unique case of a horse successfully treated for a cryptococcal fungal infection in the nose and sinuses. The study details the symptoms, diagnosis, and treatment process, highlighting the effectiveness of a combined surgical and medicational approach to manage such infections in horses.

Case Description and Diagnosis

• The article begins by describing the symptoms presented by a 12-year-old mare which included chronic mucopurulent, bloody discharge from one nostril, difficulty in breathing (inspiratory dyspnea), and respiratory noise. All these prompted an in-depth examination.
• After performing a tracheostomy to ease the horse’s difficulty in breathing, an endoscopic procedure was carried out. This revealed a tan mass extending from the middle nasal meatus into the common nasal meatus, the nasopharynx, and the right nasal cavity.
• The radiographic images exhibited soft tissue opacity in the majority of the horse’s left nasal cavity and sinuses, suggesting the presence of an abnormal mass.
• A cytologic analysis of the mass tissue subsequently revealed a classic sign of Cryptococcus neoformans infection – thickly encapsulated, budding yeast. This fungus is known to cause cryptococcosis, a condition typically epitomized by pyogranulomatous rhinitis, which the horse was suffering from.

Treatment and Outcome

• Positioned in a standing pose, the horse was sedated, and the fungal granuloma was surgically removed from the sinuses. Post-surgery, systemic antifungal drug fluconazole was administered at a specified dose for a duration of four weeks to help fight the infection.
• In addition, a topical antifungal medication, enilconazole, was applied to the sinuses every alternate day, totaling seven treatments. This was done to stop the growth of the fungus on a localized level.
• After six weeks, upon reevaluation, there was no recurrence of the infection. The surgery site, the left paranasal sinuses, showed a normal appearance and the usual cell growth (epithelialization), indicating the success of the treatment.

Conclusion and Implications

• The study concludes that in horses suffering from cryptococcosis in the sinuses, a combination of surgical removal of the granulomas and systemic and topical administration of antifungal drugs may be a curative approach. The research also establishes that the necessary surgical procedures can be effectively performed on standing, sedated horses.
• This case study implies the importance of surgical intervention coupled with an efficient drug treatment regime to tackle severe fungal infections in horses. Additionally, it suggests that a significant removal of the nasal conchae could help in easy follow-up evaluations of the sinuses via rhinoscopy.