Sarcoptic mange in pigs

摘要

Two types of Sarcoptic mange are recognized in pigs. A hyperkeratotic form found mainly in sows, and a hypersensitive form found mainly in growing pigs. The hyperkeratotic form is characterized by thick scab-like lesions, which contain large numbersof mites and are mostly found on the inner surface of the ear lobe. In severe cases, lesions may be found on the neck, along the back and over the rump. Sows are a major source of infection for growing pigs, as piglets become infested during the suckling phase. Hypersensitive mange is most common in the growing herd. Crusty scabs (hyperkeratotic mange) can be found in the ears of the piglets at weaning, but the lesions gradually reduce in size as the pigs develop a hypersensitive reaction to the mites.Pigs then develop pruritus, as well as dermatitis in the form of reddish papules over the belly, flanks, and hams. Rubbing is the main clinical sign observed. However, as the intensity of the hypersensitivity reaction varies from pig to pig, clinical signs vary significantly between pigs, even within litters. Rubbing can also lead to hair loss and abrasions, especially over the flank regions, and in severe cases pigs may develop bacterial skin infections and outbreaks of swinepox may occur. However, the most important clinical sign is reduced growth rate, which results in economic loss to the farmer.