Horses are susceptible to natural, but resistant to experimental, infection with the liver fluke, Fasciola hepatica.

The research article focuses on how horses react to infection by Fasciola hepatica, a parasite that is common in the livestock of Ireland. This was done via experimental infection and the monitoring of blood and fecal samples.

Study Objectives

• The researchers wanted to understand the susceptibility of horses to the Fasciola hepatica parasite when it’s introduced orally.
• They also aimed to trace the progression of the infection, as well as the biological and serological responses it induces in horses.

Methodology

• The team conducted an experimental infection on 10 horses (9 geldings and 1 mare) using metacercariae of Fasciola hepatica.
• Some of the horses were given higher dosage (1000 metacercariae) while others were given a lesser amount (500 metacercariae). Two horses were sham-infected, serving as the control group.
• Blood and faecal samples were collected at intervals up to 18 weeks after the infection. The samples were analysed using the ELISA method.

Findings

• No flukes were found in any of the horse’s livers and no lesions that could be connected to the Fasciola hepatica infection were observed.
• All Coproantigen ELISA results were negative for all horses, indicating the absence of parasite antigens in the faecal samples of horses.
• Three antibody detection ELISAs that are used for diagnosing the parasite infection in other species proved to be flawed on equine sera samples.

Limitations and Implications

• The study’s limitations include the relatively low number of animals used in the experiment and the short duration of the study period. The results may have been different with a larger sample size or longer study period.
• An important implication of this study is that it brings up questions on the pathophysiology and epidemiology of equine fasciolosis, as the infection did not establish after the horses were orally challenged with the parasite.