Experimental and field studies with thiophanate in pigs

Area of Science:

• Veterinary Parasitology
• Animal Health
• Pharmacology

Background:

• Gastrointestinal nematodes 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 thiophanate, alone and in combination with piperazine, against various gastrointestinal nematodes in pigs.
• To assess the ovicidal, larvicidal, and adulticidal activity of thiophanate against key swine nematode species.

Main Methods:

• Experimental infections in pigs with Oesophagostomum spp., Hyostrongylus rubidus, Trichuris suis, Ascaris suum, and Metastrongylus apri.
• Administration of thiophanate at 50 mg/kg and 200 mg/kg, and a thiophanate/piperazine combination in pellet formulations.
• Monitoring of worm burdens, fecal egg counts, and assessment of palatability and tolerance.

Main Results:

• Thiophanate demonstrated high efficacy (96-99%) against adult Oesophagostomum spp., H. rubidus, and T. suis, and was effective against larval stages, except for late-stage T. suis larvae.
• Thiophanate exhibited ovicidal and larvicidal activity against H. rubidus and Oesophagostomum spp.
• Thiophanate alone was ineffective against Ascaris suum and Metastrongylus apri, but the thiophanate/piperazine combination controlled A. suum in growing pigs.
• Field trials confirmed efficacy, with no observed palatability or tolerance issues at recommended dosages.

Conclusions:

• Thiophanate is a highly effective anthelmintic against common swine nematodes, with ovicidal and larvicidal properties.
• The combination of thiophanate and piperazine provides broader-spectrum control, including against Ascaris suum.
• These formulations offer a safe and effective approach to managing nematode infections in pigs.