Effect of vaccination against leptospirosis on the frequency, days to recurrence and progression of disease in horses with equine recurrent uveitis.

The research is about evaluating the effect of leptospirosis vaccination on the frequency, recurrence and disease progression in horses affected with Equine Recurrent Uveitis (ERU).

Research Methodology

• Forty-one horses diagnosed with ERU were used in this study.
• Randomly, they were divided into two groups – the experimental (vaccinated) and the control groups.
• The experimental group was administered with a vaccine containing six serovars of Leptospira while the control group received a placebo.
• Ophthalmic examinations were conducted and blood samples were collected on the 0th, 28th, 180th, and 365th days.
• The antibody titers against each serovar were measured.
• Recurrence of ERU was confirmed via an ophthalmic examination.

Key Findings

• The vaccination successfully heightened the average geometric mean serum antibody titer from the base figure of 225 on day 0, to 4077 and 593 on day 28 and 180, respectively.
• For the vaccinated horses, the days until first recurrence was significantly longer with a median of 126 days (range: 24-231 days) when compared to median of 86 days (range: 14-192 days) in the control group. This difference was statistically significant.
• Recurrence of ERU was observed in 35% of vaccinated horses (7 out of 20) and 57% of controls (12 out of 21), however, the difference was not statistically significant.
• More horses in the experimental group (65%) experienced progression of disease compared to the control group (57%), yet this difference was not statistically significant.

Conclusions

• The vaccine usage significantly increased the days to recurrence, but could not slow the progression of the disease.
• The findings do not support the use of vaccination against leptospirosis as an additional therapy for the routine treatment of horses with ERU.