Effect of ivermectin treatment on eosinophilic pneumonia and other extravascular lesions of late Strongylus vulgaris larval migration in foals.

The research article is about a study conducted to determine the efficacy of ivermectin treatment in reducing certain parasitic lesions and inflammation caused by the larval migration of Strongylus vulgaris in pony foals.

Research Context and Methodology

• The research was conducted on 18 parasite-free pony foals in order to assess the impact of Strongylus vulgaris, a type of parasite, and the effectiveness of ivermectin treatment on the lesions and inflammation caused due to it. Strongylus vulgaris is a common parasite in horses, and its larvae contribute to various health problems as they migrate through the various organs of the host.
• The foals were infected orally with 500 third-stage larvae of Strongylus vulgaris. After 56 days of infection, they were divided into three groups – one group was given intramuscular ivermectin, another was administered oral ivermectin while the third group was not treated at all, serving as a control group.
• Necropsy was conducted 91 days after infection to study the pathological effects of the migrating larvae and to gauge the effectiveness of the ivermectin treatment.

Findings

• The migration of the larvae induced eosinophilic inflammation, a condition characterized by an excessive accumulation of eosinophils, in the liver, spleen, mesenteric, colic and cecal lymph nodes, and small and large intestine of the foals.
• Previously unreported parasitic lesions, such as eosinophilic pneumonia with eosinophilic granulomas and pulmonary lymphoid nodules, were also observed. These lesions also have the larvae present in them calling for stronger attention towards this parasitic infection.
• The larvae were also present in the eosinophilic granulomas in the lungs, epicardium, liver, and intestinal serosa.

Conclusion

• The study found that both the injected and oral formulations of ivermectin were equally effective in reducing these lesions. This makes ivermectin a viable means of treatment for such parasitic infections in pony foals.
• The findings shed light on new types of parasitic lesions, indicating that these parasites’ impact may be more extensive than previously known. Such information is critical for formulating more effective veterinary care for ponies.