Condemnation of the large intestine or colon at slaughter is an economic loss when these are used for sausage casings. In the live pig, scouring may result from infection. Threadworm This tiny intestinal worm, Strongyloides , occurs commonly in baby pigs. Microscopic eggs are passed in the feces of pigs as young as 4 days of age. Most importantly, these infective larvae may be passed in sow colostrum so that infection takes place at first nursing.
Prenatal infections can also occur.
Heavy infections may cause intensive scouring in neonatal pigs, resulting in acute dehydration. Protective immunity develops rapidly in pigs not overwhelmed by this early infection. Mature infections are found primarily in sows, since it takes nine months to one year after infection before eggs are produced by adult kidneyworms. Because infection occurs in and around the kidneys, eggs are passed in the urine. Wooded lots and shaded farrowing pens often become contaminated areas where larvae hatch from eggs and enter the soil.