Haematopinus suis

Haematopinus suis, the hog louse, is one of the largest members of the louse suborder Anoplura, which consists of sucking lice that commonly afflict a number of mammals. H. suis is found almost solely on the skin surface of swine, and takes several blood meals a day from its host. H. suis has large claws that enable it to grasp a hog's hair and move around its body. It is easily seen without magnification, being 5–6 millimetres (0.20–0.24 in) long. H. suis has a long, narrow head and long mouthparts adapted for sucking blood. It is the only louse found on swine. H. suis infestation is relatively rare in the US; a 2004 study found that about 14% of German swine farms had H. suis infestations. Due to the frequency of feeding, infected swine become severely irritated, often rubbing themselves to the point of injuring their skin and displacing body hair. Particularly afflicted hogs may become almost completely bald and, in young hogs, the resulting stress can arrest growth, a cause of concern for farmers.