Capillaria plica is often found in the urine, urinary bladder or kidneys of dogs and cats in North America, Europe, Asia and Africa.

It has also been identified in the urinary bladder and kidneys of several wild mammals in North America and Europe: In dogs and cats, eggs of Capillaria plica are released in the urine of the mammalian definitive host.

Here they mature into adults and reproduce sexually, shedding fertilized eggs into the urine of the host within about 60 days of infection.

[5] Detailed life cycle studies have not been carried out with wild animal definitive hosts.

[2] Diagnosis in cases of hematuria or cystitis is made by finding eggs in the urine sediment.