Equine antibody response to larval Parascaris equorum excretory-secretory products.

This research primarily addresses the limitation of current diagnostic methods for detecting equine Parascaris equorum infection, a type of intestinal worm in foals and young horses. It investigates if equine IgG(T) antibodies against larval P. equorum worms could be detected using a western blot test, which could potentially diagnose the infection earlier, even before parasites lay their eggs.

Detailed Explanation

Introduction and Objective

• This study focuses primarily on an intestinal worm that affects young horses and foals named Parascaris equorum. The pathology produced by this worm can range from mild to severe.
• Diagnostic methods are currently limited, detecting only existing infections, typically by identifying parasite eggs during fecal examinations.
• The primary objective of the study is the potential use of the larval P. equorum’s excretory-secretory (ES) products to identify the presence of specific IgG(T) antibodies in the horse. These antibodies could serve as markers for a prepatent infection – one at an early stage, even before parasites start laying their eggs.

Methodology and Experiment Setup

• The researchers used sera (blood plasma) samples collected from different groups including those from adult mares that had no existing P. equorum infection, foals before they consumed colostrum, and P. equorum infected foals for comparison.
• Additionally, sera from 18 broodmares prior to giving birth and their foals during natural infection were also examined.
• The major component of the experiment was the examination of IgG(T) antibodies in these sera with ES products.

Results and Findings

• The study found that foals naturally infected with P. equorum had IgG(T) antibodies against ES products of specific molecular weights: 19kDa, 22kDa, 26kDa, and 34kDa.
• However, the study found a complication in using this method for early diagnostics. It seems antibodies from the mare present in the colostrum (a mother’s first milk that is rich in antibodies) could interfere with the identification of these specific IgG(T) antibodies.

Conclusion

• The passive transfer of these colostral antibodies prevents the successful usage of a western blot test with crude larval ES products for diagnosing early (prepatent) P. equorum infections in foals.