Risk factors for insidious uveitis in the Knabstrupper breed

Area of Science:

• Veterinary Ophthalmology
• Equine Genetics
• Animal Disease Epidemiology

Background:

• Equine recurrent uveitis (ERU) is a primary cause of equine blindness.
• The leopard complex spotting (LP) allele is a known risk factor for ERU in Appaloosas.
• Limited data exists on ERU risk factors in Knabstrupper horses.

Purpose of the Study:

• To investigate clinical signs, disease frequency, and potential risk factors for ERU in Knabstrupper horses.
• To assess the association between the LP allele and ERU in Knabstruppers.
• To evaluate the role of age and coat color genetics in ERU susceptibility.

Main Methods:

• A cross-sectional study involving ocular examinations of 116 Knabstrupper horses.
• Risk factor analysis included clinical signs, age, sex, coat color, LP and PATN1 genotypes, and Leptospira exposure (MAT).
• Multivariable exact logistic regression and pedigree analysis (coefficients of coancestry and inbreeding) were employed.

Main Results:

• The prevalence of insidious uveitis in the Knabstrupper sample was 20.7%.
• LP homozygotes (LP/LP) showed significantly higher odds of uveitis compared to solid-colored horses (OR = 7.64, p=0.04).
• Older age (16-20 years) was also a significant risk factor for ERU (OR = 13.36, p=0.009), as were differences in average coefficients of coancestry between cases and controls (p=0.01).

Conclusions:

• Genotyping for the LP allele is recommended for assessing ERU risk in Knabstruppers.
• Age is a significant risk factor for ERU in this breed.
• Further research is needed to develop comprehensive risk models for early ERU detection and management across breeds.