Alternative methods for the control of sheep scab

Area of Science:

• Veterinary Parasitology
• Sheep Health Management
• Chemical Control of Ectoparasites

Background:

• Plunge dipping was the sole method for sheep scab control in the UK for 17 years.
• Dipping poses risks to human health and the environment due to dipwash disposal.
• Deregulation in 1992 allows for alternative scab control methods.

Purpose of the Study:

• To evaluate alternative sheep scab control methods post-deregulation.
• To compare the efficacy of systemic injectables and synthetic pyrethroid pour-ons against traditional plunge dipping.
• To assess the effectiveness of ivermectin injections for sheep scab management.

Main Methods:

• Review of existing literature on sheep scab control methods.
• Analysis of the efficacy of systemic injectables (ivermectin) and synthetic pyrethroid pour-ons.
• Comparison of scab control effectiveness based on mite burden and treatment protocols.

Main Results:

• Plunge dipping is highly effective against scab and other ectoparasites.
• Current systemic pour-ons and oral drenches show limited efficacy against scab.
• Double injections of systemic acaricides like ivermectin demonstrate significant potential for scab control.
• Synthetic pyrethroid pour-ons leave sheep vulnerable to reinfestation due to incomplete coverage.

Conclusions:

• While plunge dipping is effective, alternative methods are sought due to its disadvantages.
• Systemic injectables, particularly ivermectin with a second dose, offer a promising alternative to dipping.
• Careful administration and adherence to treatment protocols are vital for the success of injectable acaricides in sheep scab eradication.