Ocular changes in a horse with gutturomycosis

Area of Science:

• Veterinary Medicine
• Mycology
• Neurology

Background:

• Guttural pouch mycosis can cause serious complications in horses.
• Fungal infections can spread and affect neurological structures.
• Ocular and neurological deficits are potential sequelae of guttural pouch disease.

Purpose of the Study:

• To describe a case of fungal granuloma in the guttural pouch of a horse.
• To investigate the cause of epistaxis, visual disturbances, and blindness in a gelding.
• To identify the fungal species responsible for the granuloma.

Main Methods:

• Clinical examination of a 7-year-old gelding with recurrent epistaxis and visual deficits.
• Diagnostic imaging to assess the extent of the guttural pouch lesion.
• Histopathological examination of affected tissues, including the guttural pouch, optic nerves, and brain.
• Microscopic identification of fungal elements.

Main Results:

• A spreading fungal granuloma of the guttural pouch was identified as the cause.
• The granuloma extended to the intracranial optic nerve and optic chiasma.
• Histopathology revealed ischemic infarction in the retina, optic nerves, optic chiasma, and optic lobe.
• Fungal elements were morphologically consistent with Aspergillus sp.

Conclusions:

• Fungal granulomas of the guttural pouch can lead to severe neurological and visual impairment in horses.
• Aspergillus species should be considered in cases of guttural pouch mycosis with neurological signs.
• Prompt diagnosis and treatment are crucial to prevent irreversible damage.