Serum protein changes in ponies on different parasite control programmes.

The research examines the effect of different parasite control programs on serum protein responses in ponies. Significant protein changes only occurred in younger ponies and were found to be influenced by the type of parasitic infection, indicating limited usefulness of serum protein and IgG(T) responses for diagnosing parasitism due to interpretation difficulties.

Research design and analysis

• The study was conducted on 52 ponies which were divided into five groups. Each group was subjected to different parasite control strategies.
• The intensity of pasture infectivity, measured as the number of infective third stage, cyathostome, and Trichostrongylus axei larvae per kilogram of herbage, varied among the groups. The range of infectivity was between 706 to 18,486 L3/kg by 17 September 1984.
• The research analyzed changes in serum proteins, with a specific focus on beta-globulin, immunoglobulin (Ig)G(T), and serum albumin concentrations.

Findings

• Significant protein changes were observed only in young ponies (Groups 4 and 5), and these changes were evident before these ponies were exposed to the maximum numbers of pasture larvae.
• The primary infection of Trichostrongylus axei seemed to stimulate serum beta-globulin and IgG(T) responses more than continued infection with cyathostome worms did.
• No large strongyle parasites were detected in any larval cultures or on pastures grazed by the young ponies.
• In Group 5 ponies, beta-globulin and IgG(T) concentrations declined a month after treatment with ivermectin, suggesting a larvicidal action against Trichostrongylus axei and/or cyathostome worms.
• A subsequent increase in serum albumin concentrations in the same group indicated that a protein-losing gastrointestinal disease had been alleviated by ivermectin’s larvicidal action.
• In comparison, mature ponies (Group 1) exposed to heavily infected pastures showed little beta-globulin response and only a modest IgG(T) response.

Conclusion

• The research concluded that serum protein and IgG(T) responses provide limited diagnostic value for parasitism due to the multiple complications arising when interpreting results.