Apparent inactivity of several antiparasitic compounds against the eyeworm Thelazia lacrymalis in equids.

The research article investigates the effectiveness of 15 antiparasitic compounds in the treatment of Thelazia lacrymalis, an eyeworm found in equids, and concludes that none of the compounds show noticeable activity against this parasitic infection.

Background

• The study focused on Thelazia lacrymalis, a type of eyeworm that affects equids, a family of mammals that includes horses, donkeys, and zebras.
• These eyeworms cause irritation, inflammation, and potential damage to the eye, which can impair vision and overall health of the animal.

Methods

• The researchers tested 15 different compounds independently or in combination, which included: butamisole, cambendazole, caviphos, febantel, fenbendazole, ivermectin, levamisole-piperazine, oxfendazole, oxibendazole, pyrantel pamoate, thiabendazole, tioxidazole, and trichlorfon.
• These compounds were administered to 102 equids infected with Thelazia lacrymalis.
• The activity of the compounds was evaluated based on the comparison of the infection rate in treated animals with the infection rate in untreated ones.

Results

• The results showed that none of the 15 tested antiparasitic compounds presented notable activity against Thelazia lacrymalis.
• The evaluation was done postmortem, which enabled the researchers to directly observe and compare the presence and frequency of the eyeworm in treated and untreated subjects.

Conclusion

• This research concludes that none of the tested antiparasitic compounds, either used alone or in combinations, effectively combat Thelazia lacrymalis in equids.
• These findings suggest that existing treatment options for this parasitic infection are ineffective and that more research is needed to identify and test novel antiparasitic compounds against Thelazia lacrymalis.