A comparison of the bioequivalence of 0.5% fenbendazole top dress pellets or 10% fenbendazole oral suspension against a spectrum of equine parasites.

This study assessed the effectiveness of two types of deworming treatments on horses, and observed both treatments were equally successful controlling parasitic infections. It also highlighted the need for adequate sample sizes when assessing the presence of larger parasites.

Overview of the Research

• This study compared the bioequivalence of two different fenbendazole (FBZ) formulations: 0.5% Top Dress Pellets and 10% Oral Suspension. Fenbendazole is a common medication used to treat a variety of parasitic infections in animals.
• The experiment tested 30 horses with naturally occurring parasite infections. The horses were divided into groups of three, with each group receiving either the pellet treatment, the suspension treatment, or no treatment at all (control group).

Analysis of Parasitic Infections

• Before treatment, there was no significant difference in the presence of strongyle eggs (a type of parasitic worm) among the three groups of horses.
• After treatment, both the group treated with the pellet formulation and the group treated with the suspension formulation showed a significant reduction in strongyle eggs, compared to the untreated control group.

Post-mortem Examination

• A post-mortem exam was performed seven to nine days post-treatment, during which two different methods of recovering parasites from the horses were compared in order to test their efficacy in identifying both large and small strongyles.
• Both recovery methods proved equally efficient in recognizing and accounting for the presence of the strongyles among the horses. However, a substantial discrepancy was noticed in the number of worms recovered by each method.

Therapeutic Bioequivalence

• Both the 0.5% pellet formulation and the 10% suspension formulation demonstrated therapeutic bioequivalence – that is, they were equally as effective in treating the horses’ parasitic infections.
• The six species of small strongyles making up 96% of all the small strongyles recovered were identified as Coronocyclus coronatus, Cylicocyclus insigne, Cylicostephanus longibursatus, Cylicocyclus brevicapsulatus, Cylicocyclus nassatus, and Cyathostomum catinatum.

Significance of Study Results

• The researchers concluded that it’s necessary to sample at least 10% of the infested population to get accurate estimates of the number of the larger type of strongyles. Smaller sample sizes may lead to underestimated or misrepresented data.
• No adverse effects were observed from either treatment, signifying that both are safe for use in horses.