name(s) of disease causative agent nature of disease

Coccidiosis protozoans (e.g., Emieria affected birds show low egg production, poor growth rates, and high mor-

tenella) tality; cecal coccidiosis (the cecum is a pouch in the large intestine), a

serious disease caused by tenella; many protozoa produce intestinal

symptoms

Blackhead (histo- protozoan (Histomonas may kill up to 50 percent of a turkey flock; symptoms include droopy

moniasis) meleagridis) wings and damage to liver and cecum; Heterakis gallinae, a worm in

the turkey cecum, probably transmits the protozoan

Psittacosis (orni- virus (Bedsonia) affects parakeets, canaries, parrots, pigeons, and other pet birds; symptoms

thosis) include lack of appetite, ruffled feathers; can be transmitted to humans

Avian lymphomato- virus an infectious disease; manifestations include formation of tumours; three

sis forms occur, depending on location of tumours: visceral (internal

organs); neural (nerve); and ocular (eye) lymphomatosis

Pullorum disease bacterium (Salmonella pul- affects most species of fowl (chickens); mortality rate high, also reduces

lorum) egg productivity of mature females; transmitted from egg-producing

organs of hen to chick; disease causes hemorrhages throughout body

Digestive diseases in functional disturbance symptoms include slowly emptying, loosely hanging crop (digestive organ);

caged birds deficiency of grit (particles that aid in digestion) results in poor

nutrition; symptoms include obstruction of crop, vomiting, intestinal

inflammation, and various liver disorders

Fractured legs in physical agent in canaries, about 70 percent of fractures involve the metatarsus (hind-

caged birds foot); in budgerigars, 70 percent involve the tibia (hindleg)