Authors: Gehlen Heidrun, Inerle Katharina, Bartel Alexander, Stöckle Sabita Diana, Ulrich Sebastian, Briese Beatrice, Straubinger Reinhard K
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Lyme Borreliosis Seropositivity in German Horses Lyme borreliosis (LB) and anaplasmosis are tick-borne infections of potential concern in equine practice, yet the clinical significance of positive antibody tests in horses remains poorly understood, particularly in European populations. Researchers in Germany tested 123 horses presenting with clinical signs suggestive of LB (primarily lameness, poor performance, and apathy) and 113 clinically healthy control horses from the same premises, screening all samples for antibodies against *Borrelia burgdorferi* sensu lato and *Anaplasma phagocytophilum* using ELISA, immunoblot assays, and rapid in-house testing. Seropositivity rates were remarkably similar between groups: 23% of suspect horses versus 17% of healthy controls tested positive for *B. burgdorferi* (p = 0.371), whilst *Anaplasma phagocytophilum* seropositivity occurred in 20% and 16% respectively, with dual infection in only 6% and 2%. These findings underscore a critical diagnostic challenge—antibody detection alone cannot establish a diagnosis of equine Lyme borreliosis, as exposure to these pathogens appears common but clinical disease manifestation remains inconsistent. Practitioners should avoid reflexive serological screening in the absence of specific clinical suspicion, instead reserving testing for horses with compatible clinical signs and considering seronegativity alongside other differential diagnoses when investigating lameness and performance issues.
Read the full abstract on PubMed
Practical Takeaways
- •Do not rely on antibody serology alone to diagnose Lyme borreliosis in horses; clinical signs and epidemiological context are essential for interpretation
- •Routine serological screening for Borrelia burgdorferi without clinical suspicion is not recommended and may lead to misdiagnosis
- •When evaluating lameness, poor performance, or apathy in horses, consider that seropositivity does not confirm active disease—further diagnostic investigation is necessary
Key Findings
- •23% of horses suspected of Lyme borreliosis and 17% of clinically healthy horses were seropositive for Borrelia burgdorferi sensu lato (p = 0.371), with no significant difference between groups
- •Anaplasma phagocytophilum seropositivity was 20% in suspect horses versus 16% in healthy horses (p = 0.108), showing only minor differences
- •Dual seropositivity (both pathogens) was 6% in suspect horses and 2% in healthy horses
- •Seropositivity to Borrelia burgdorferi alone is not sufficient for diagnosis of equine Lyme borreliosis due to lack of clinical correlation