infected with this intestinal worm, primarily in africa and asia. about 120 to 220 million of these cases are symptomatic. deaths as of 2010, ascariasis caused about 2,700 directly attributable deaths, down from 3,400 in 1990. the indirectly attributable deaths due to the malnutrition link may be much higher. research there are two animal models, the mouse and pig, used in studying ascaris infection. other animals ascariasis is more common in young animals than mature ones, with signs including unthriftiness, potbelly, rough hair coat, and slow growth. in pigs, the infection is caused by ascaris suum. it is characterized by poor weight gain, leading to financial losses for the farmer. in horses and other equines, the equine roundworm is parascaris equorum. society and culture kings of england richard iii and henry viii both had ascariasis.