Giardia is a tiny organism, called a protozoa, made of only one cell! Infection with giardia is quite rare in ferrets, but can occur. Although any ferret can be affected with giardia, it is more likely in young ferrets or ferrets who are densely housed.
Giardia reproduce in the intestines by producing special infectious cysts which are released into the environment in faeces. Ferrets who ingest these cysts are then infected themselves. Giardia can infect many animals as well as ferrets, including cats, dogs and humans. This means that ferrets who are in contact with other animals are much more at risk of giardia.
Giardia can be difficult to diagnose, as ferrets which are affected often only have giardia in their faeces intermittently and may show no signs of infection. This means that a test can be negative, even if giardia are actually present – repeated tests may be needed to track this little parasite down!