A follow up study on antibodies against Lawsonia intracellularis in mares and foals from two breeding farms in Germany.

The research article investigates the prevalence of antibodies against Lawsonia intracellularis, a bacterium associated with a disease called Equine proliferative enteropathy (EPE) in horses, in healthy adult mares and their foals in two German horse breeding farms.

Objective of the Research

• The study aimed to examine the frequency of L. intracellularis antibodies in horses from two German breeding farms considering a past record of the bacteria in Germany.

Research Method

• The research was conducted on two groups of horses.
• In the first group, researchers collected serum samples from 24 and 16 Haflinger mares and their foals in two different years respectively.
• In the second group, serum samples of six warmblood mares and foals were obtained monthly over a five-month period until the foals were identified as seronegative.
• The collected serum samples were then tested using an ELISA (Enzyme-linked Immunosorbent Assay) system.
• The output of the test was expressed as Percentage of Inhibition (PI). A PI score higher than 30 was considered positive for L. intracellularis antibodies.

Results of the Research

• All adult mares from both groups were seropositive at all points in time.
• In the first group, some foals were found to be seropositive, 29.2% in the first year and 25% in the second year.
• Interestingly, the seropositive foals from the second year had the same dams as the seropositive foals from the first year.
• In the second group, among the six foals, five were seropositive after birth. However, the antibody levels decreased from March to July in both mares and foals.
• By July, all five foals tested negative for the first time between the ages of 82 and 141 days (with a median age of 115 days).
• It was noted that the PI-values of mares were significantly related to the PI-values of their foals. Younger foals and those born in spring had higher PI values.

Conclusion of the Research

• The loss of antibodies in foals observed between the age of three to five months could make them susceptible to L. intracellularis infection and be responsible for the emergence of Equine proliferative enteropathy (EPE).