Efficacy of ivermectin in the treatment of induced Parascaris equorum infection in pony foals.

This research paper investigates the effectiveness of ivermectin, in both paste and liquid forms, in treating infections of Parascaris equorum, a parasite, in foals. Administered in controlled doses, the study found both forms of ivermectin were successful in significantly reducing the number and size of the parasitic larvae.

Research Methodology

• This research was carried out on 18 pony foals. All the foals were infected with an average of 1500 infective Parascaris equorum eggs.
• The method of administration of ivermectin varied between orally given paste and liquid forms.
• All treatments were issued on post-inoculation day (PID) 28, meaning 28 days after the foals had been infected. This provided ample time for the parasites to establish.
• The control group received a vehicle (i.e., a substance with no therapeutic effect) of 0.02 ml per kg of body weight as a comparison to the treated groups.

Results and Findings

• The medicine was found to be effective in reducing the number of parasites. The mean number of fourth-stage P. equorum larvae in the groups treated with ivermectin paste and liquid were 3.5 and 6, respectively.
• The control group, which was given the ivermectin vehicle, was found to have significantly higher mean numbers of larvae, at 1250.
• Not only this, but the length of the larvae in the control group was significantly higher than those in the treatment group, implying that ivermectin helped inhibit the growth and development of the parasites.
• The gross examination of the foals’ lungs and liver showed that despite the treatment, the physical damage caused by the parasites was similar in all animals. This suggests that the active phase of the infection can trigger pathological changes regardless of successful treatment later on.
• The treatment with ivermectin, whether in paste or liquid form, did not cause any adverse reactions, indicating its safety for use in foals.

Conclusion

• Ivermectin, in both paste and liquid forms, can effectively reduce the burden of P. equorum infection in foals. The research shows it can decrease now only the number but also the size of these parasitic larvae. However, physical damage due to infection might continue irrespective of successful treatment.