Cryptosporidiosis is the name of the disease caused by infection with protozoan parasites of the genus
Cryptosporidium. Cryptosporidial parasites predominately infect the epithelium of the intestinal tract, presenting as a gastrointestinal disease or respiratory disease.
Cryptosporidium is typically opportunistic and more likely to infect young and/or immunocompromised birds. Infection of the bursa (bursal cryptosporidiosis) is commonly seen in chickens with
Infectious Bursal Disease virus or
Chicken Infectious Anemia virus.
There are many species of
Cryptosporidium that infect a wide range of animal species, including humans. The following
Cryptosporidium species have been reported to infect chickens:
- Cryptosporidium baileyi: Infects the Bursa of Fabricius, conjunctiva, kidneys, respiratory tract, cloaca, or rectum. Found worldwide and in a wide range of bird species.
- Cryptosporidium meleagridis: Infects the small and large intestines. Found in Columbiformes, Galliformes, Passeriformes, and Psittaciformes worldwide.
- Cryptosporidium galli: Infects the proventriculus. Affects chickens in Asia, Europe, Oceania, and South America. Found in Bucerotiformes, Galliformes, Passeriformes, Psittaciformes, and Phoenicopteriformes.
- Cryptosporidium andersoni: Affects chickens and other Galliformes in Europe.
- Cryptosporidium parvum: Infects the small intestine or caecum. Found in Accipitriformes, Anseriformes, Charadriiformes, Galliformes, Passeriformes, and Psittaciformes in Asia, Europe, and the Americas.
How Chickens get Cryptosporidiosis
Chickens become infected by ingesting
Cryptosporidium oocysts excreted in the feces and surrounding environment from an infected host. The host doesn't need to be a chicken. Many other bird species can be infected hosts. Oocysts are capable of surviving outside their host for long periods of time (often greater than 6 months duration) in cool, moist environments, especially water sources.
How Cryptosporidiosis is Diagnosed
Cryptosporidium is detected in the conjunctiva, sinus, trachea, lungs, kidneys, small and large intestine, cloaca, and bursa of Fabricius in chickens.
Cryptosporidiosis Treatment
Cryptosporidiosis can be difficult to treat. The most important aspect of treatment is strengthening the bird's immune system, since infection with this organism tends to occur most frequently in birds with compromised immune systems. Identification and treatment of any underlying diseases and improving basic care are also paramount.
