The infective L1 stage larvae is encysted in the muscle fibres. On passage through the stomach of the host, the worm is released from the cyst. In the small intestine the larvae rapidly penetrates the mucosa where it undergoes successive moults to become young adults, within 30 hrs post-infection. These young adults mate deep within the mucosa where they are regarded as being intracellular parasites, lying within a serial row of cells. The female worms produce about 1500 larvae over about 4-6 weeks.
Males die soon after copulation and the females die shortly after the completion of oviposition.
The L1 larvae enter the circulatory system and spread throughout the body finally targeting the hosts muscle cells where they penetrate the individual muscle cells. They have a predilection for highly active muscles such as the tongue, masticatory muscles, intercostal muscles, diaphragm, eye muscles and the muscles of the arms and legs. The L1 larvae absorb nutrients from the muscle cells and increase their length to about 1 mm. They finally form themselves into a spiral shape, where they remain dormant until eaten and enter the digestive system of the next host. The muscle cell containing the larvae is surrounded by infiltrating lymphocytes and result in a cyst wall surrounding the cell.