Mycotic Rhinitis and Sinusitis in Florida Horses.

This research studied rhinitis and sinusitis caused by fungal pathogens in horses from various parts of Florida using biopsy samples from 52 horses. Findings indicate that the most common forms of fungal rhinitis found in Florida horses were Zygomycosis and Phaeohyphomycosis.

Study Methodology

• The researchers gathered biopsy samples from 52 horses located in the subtropical and tropical regions of Florida.
• They used routine histopathology (study of the microscopic structure of tissues) in order to examine the samples. They also used Polymerase Chain Reaction (PCR) with panfungal/panoomycete primers and conducted DNA sequencing on the extracted DNA (a method known as DNA barcoding).

Findings

• They discovered that granulomatous, pyogranulomatous, and fibrinopurulent lesions in the nasal and sinus mucosa of the horses were associated with signs of upper airway obstruction, noise as well as nasal discharge.
• Through morphologic and histochemical assessment, they identified numerous cases of different types of fungal infections such as zygomycosis, pythiosis, phaeohyphomycosis, and other lesser-known fungi.
• PCR testing and DNA sequencing helped the researchers identify the fungal pathogens in around 21% (11 of the 52) cases.
• Interestingly, there was no evidence of oomycete infection found amongst the samples.
• The research also described the histomorphologic features of previously unrecognized forms of equine rhinitis/sinusitis caused by various fungi.
• The use of panfungal and oomycete primers with DNA from formalin-fixed and paraffin-embedded specimens successfully identified the pathogens in different types of fungal infections with varying rates of success.
• In this study, Zygomycosis and Phaeohyphomycosis were found to be the most prominent forms of fungal rhinitis among Florida horses.

Conclusion

• This research provides valuable information about the prevalence of different types of fungal infections in horses in Florida. It underscores the effectiveness of the techniques used, such as PCR testing and DNA sequencing, in identifying the specific fungal pathogens causing rhinitis and sinusitis in these animals.
• The findings about the most common types of fungal rhinitis could be used to inform preventive measures and treatments to improve the health of horses in the region.