Multimodal treatment of recurrent sinonasal cryptococcal granulomas in a horse.

The study examines a case of a 7-year-old horse with sinus fungal infection (cryptococcal granulomas), traditionally viewed as incurable, that was successfully treated with a combination of medical and surgical strategies. A remission period of 2.5 years was achieved initially, after which the disease reappeared and further treatments were administered, resulting in another two years of symptom-free health.

Research Method

• The research is a case study of a single Tennessee Walking Horse mare, exhibiting symptoms including bilateral nasal discharge, occasional nosebleeds and worsening trouble in breathing.
• Preliminary investigations included endoscopic and radiographic examinations that revealed multiple masses in the nasopharynx region. Further cytologic and histologic examinations of biopsy samples were conducted to identify the cause of the masses.
• The cells were found to be similar to cryptococcal organisms, indicating a possible Cryptococcus neoformans infection.

Treatment Approach

• The initial treatment strategy consisted of administering fluconazole and ethylenediamine dihydriodide orally, along with intermittent injections into the lesions with fluconazole, amphotericin B, and formalin. This led to the resolution of symptoms for a period of 2.5 years.
• When the symptoms re-emerged, the horse underwent surgical debulking to reduce the nasopharyngeal masses, carried out through a large frontonasal bone flap.
• Post-surgery, the horse was treated with IV injections of amphotericin B and long-term oral intake of fluconazole. This treatment strategy resulted in another two years of good health, free from symptoms.

Conclusions and Implications

• While fungal infections, particularly of the upper respiratory tract in horses, have traditionally been viewed as fatal, this case study demonstrates that a combination of medical and surgical interventions could potentially successfully treat the condition.
• This case underscores the importance of long-term monitoring and follow-up of such conditions, given the potential for recurrence.
• The study suggests that with the formulation of less expensive antifungal agents, these medicines may see increased usage, leading to reduced mortality rates in horses suffering from fungal infections.