Doramectin efficacy against gastrointestinal nematodes in pigs

Area of Science:

• Veterinary Parasitology
• Animal Health
• Pharmacology

Background:

• Nematode infections pose significant health and economic challenges in swine production.
• Effective anthelmintic treatments are crucial for maintaining pig health and productivity.

Purpose of the Study:

• To evaluate the efficacy of doramectin in treating growing pigs against natural and experimentally induced nematode infections.
• To determine the efficacy of doramectin against specific nematode species affecting swine.

Main Methods:

• Four controlled trials were conducted involving growing pigs with natural or induced nematode infections.
• Pigs were treated with doramectin (300 micrograms/kg) or saline (control) via intramuscular injection.
• Parasite burdens were assessed through necropsy 14-15 days post-treatment.

Main Results:

• Doramectin achieved high efficacy against natural infections: Ascaris suum (100%), Oesophagostomum spp. (100%), Hyostrongylus rubidus (99.4%), and Strongyloides ransomi (99.9%).
• Efficacy against induced infections included: 4th stage A. suum (100%), O. dentatum (99.9%), O. quadrispinulatum (97.1-99.6%), H. rubidus (100%), adult S. ransomi (100%).
• Efficacy against adult Trichuris suis was 54.1% in mixed infections and 95.3% in pure infections.

Conclusions:

• Doramectin is highly effective against a broad spectrum of nematodes in growing pigs under experimental conditions.
• The drug demonstrates excellent efficacy against most tested nematode species, with notable exceptions for Trichuris suis in mixed infections.