Nutritionally variant streptococci associated with corneal ulcers in horses: 35 cases (1982-1988).

This study examines the connection between nutritionally variant streptococci (NVS), a type of bacteria, and corneal ulcers in horses. The researchers found that NVS were present in nearly 13.5% of examined horses suffering from these ulcers.

Understanding NVS

• Nutritionally variant streptococci (NVS) are a special type of viridans streptococci that need pyridoxal (a form of vitamin B6) for growth.
• Although NVS are well known for causing diseases in humans, there wasn’t recorded impact of these bacteria on the health of domestic animals before this study.

The Study and its Background

• In 1982 and 1983, the researchers found 24 cases where NVS were isolated from horses that had ulcerative keratitis, which refers to the inflammation and ulceration of the cornea.
• This prompted the researchers to conduct a more comprehensive retrospective study to establish the prevalence of NVS in horses affected by corneal disease.

Study Methodology

• The researchers reviewed the medical records of 249 horses (259 eyes in total) that showed clinical signs of corneal disease.
• This extensive review was done to trace for any presence of NVS, and to understand its prevalence in the horses suffering from corneal ulcers.

Findings

• The study found nutritionally variant streptococci in approximately 13.5% cases of horses with ulcerative keratitis.
• This underscores the pathogenic role of NVS in domestic animals, specifically, horses.

Implications

• The results indicate a need for further research to understand more in-depth the role of NVS in ulcerative keratitis and shortfalls in the horse’s nutrition which lead to such infections.
• Finding NVS pathogenicity in horses could reshape the diagnostic approach and therapeutic strategies for corneal disease in equine practice.