Adult worms live primarily in the right kidney of mink, but many other mammals including humans are susceptible. Eggs pass in the urine and embryonate in about 3 weeks. When eaten by an annelid, the L1 hatches, moves to the tissues, molts to the L2 and encysts. Annelids often attach to crayfish. When the crayfish is eaten by a suitable fish, the L2 penetrates the gut and arrives at the fish's mesenteries. There it molts to the L4 and encysts. After ingestion by a mink, the L4 leaves the digested fish and penetrates the stomach, which happens to be nearest the right kidney, and therefore tend to infect the right kidney. It is possible for the larvae in annelids to directly infect the final host, so the fish might be considered a paratenic host even though some development within the fish can occur. The entire life cycle may take more than 1 year to complete.