Diagnosis of Borrelia-associated uveitis in two horses.

This research article discusses the diagnosis of Lyme disease-associated uveitis, an ocular disorder, in two horses, evidencing the condition through the detection of Borrelia burgdorferi spirochetes in ocular fluids.

Summary of Findings

This study’s focus was to elucidate the association of Borrelia burgdorferi, the causative agent of Lyme disease, with the onset of uveitis in horses. The authors found the link by detecting spirochetes, a bacterium type associated with Lyme disease, in ocular fluids of afflicted horses, which was confirmed through PCR testing.

• Lyme disease is a tick-born infection. In horses, Lyme borreliosis can lead to various disorders such as musculoskeletal, neurological, reproductive, and ocular issues, including uveitis.
• However, a definitive diagnosis could be challenging as the causative agent B. burgdorferi is rarely isolated and serologic tests can sometimes be unreliable.
• In this study, the researchers used a combination of cytologic assessment, antibody testing, and PCR testing to diagnose equine Lyme borreliosis.

Challenges in Diagnosis

Several problems were highlighted regarding the diagnosis of equine Lyme borreliosis.

• The clinical symptoms are often vague and non-specific.
• B. burgdorferi, the causative agent of the disease, is seldom isolated, making it difficult to confirm the infection.
• Serologic tests, which can be used to diagnose the disease, could be unreliable and do not necessarily confirm active disease.

Recommendation and Conclusion

Despite the challenges, Lyme disease should be considered a differential diagnosis in the event of equine uveitis. This is especially recommended for horses in regions where Lyme disease is prevalent. To confirm the disease, the authors propose a combination of cytologic assessment, antibody, and/or PCR testing.

• PCR testing is a potential solution that can help identify spirochetes in ocular fluids. This not only helps to confirm the presence of the bacteria but also validates the onset of active Lyme disease.
• However, despite this combination of methods, the authors assert the possibility of false-negative serum test results during uveitis associated with B. burgdorferi and failure of such tests to confirm active infection. Hence, a high clinical suspicion for Lyme uveitis is necessary for initiating the combined testing.