THE TRICHOMONA DS 



99 



Disease : Avian trichomonosis, upper 

 digestive tract trichomonosis. 



Hosts : The domestic pigeon is the 

 primary host of T. gallinae. but it also 

 occurs in a large number of other birds, 

 including hawks and falcons which feed on 

 pigeons. Its natural hosts besides the 

 pigeon include the mourning dove {Zen- 

 aidura macroura), Indian dove ( Turtiir 

 siiratensis), wood pigeon [Columba pa- 

 lumbiis), band-tailed pigeon (C. fasciata), 

 ring dove {Streptopelia risoria), white- 

 winged dove {Zenaida asiatica), turkey, 

 chicken, Cooper's hawk {Accipiter cooperi), 

 golden eagle {Aquila chrysaetos), duck 

 hawk [Falco peregrinus anatiini), Java 

 sparrow {Miinia oryzivora), zebra finch 

 and orange-cheeked waxbill. 



A number of other birds have been 

 experimentally infected. They include the 

 bobwhite quail, canary, English sparrow 

 (Levine, Boley and Hester, 1941), barn 

 swallow, goldfinch and song sparrow 

 (Stabler, 1953), and Tovi parakeet and 

 Verraux's dove (Callender and Simmons, 

 1937). Parenteral infections have also 

 been produced experimentally in mammals 

 --by Bos (1934) in mice and guinea pigs, 

 by Wagner and Hees (1935), Wittfogel 

 (1935), Miessner and Hansen (1936), 

 Schnitzer, Kelly and Leiwant (1950) and 

 Honigberg (1959) in mice, and by Rakoff 

 (1934) in rats and kittens. 



Prevalence : T. gallinae is extremely 

 common in domestic pigeons, in which it 

 often causes serious losses. It is fairly 

 common in the turkey; the U.S. Dept. of 

 Agriculture (1954) estimated that it causes 

 an annual loss of $47,000 in these birds. 

 It is rare in chickens. It is common in 

 mourning doves, and may cause serious 

 losses among them (Stabler and Herman, 

 1951). According to Stabler (1954), it was 

 common in trained hawks during the hey- 

 day of falconry; they became infected be- 

 cause they were fed largely on pigeons. 

 Stabler and Herman (1951) and Stabler 

 (1954) give further information on incidence 

 in domestic and wild birds. 



Morphology : The following description 

 is based on Stabler (1941, 1954). The body 



Fig. 12. Trichomonas gallinae 

 (From Stabler, 1947) 



X 3400. 



is roughly piriform, 6 to 19 by 2 to 9 |j,. 

 Four anterior flagella 8 to ISfi long arise 

 from the blepharoplast. The axostyle is 

 narrow and protrudes a short distance 

 from the body. There is no chromatic 

 ring around its point of emergence. The 

 parabasal body is sausage-shaped, about 

 4|i long, with a parabasal filament. The 

 costa runs 2/3 to 3/4 of the body length. 

 The undulating membrane does not reach 

 the posterior end of the body. An acces- 

 sory filament is present. A free trailing 

 flagelium is absent. A cytostome is 

 present. There are 6 chromosomes. 



Pathogenesis : In the pigeon, tricho- 

 monosis is essentially a disease of young 

 birds; 80 to 90?o of the adults are infected 

 but show no signs of disease. The sever- 

 ity of the disease varies from a mild con- 

 dition to a rapidly fatal one with death 4 to 

 18 days after infection. This is due in 

 part to differences in virulence of different 

 strains of the trichomonad (Stabler, 1948). 

 Severely affected birds lose weight, stand 

 huddled with ruffled feathers, and may fall 

 over when forced to move. A greenish 

 fluid containing large numbers of tricho- 

 monads may be found in the mouth. 



Lesions are found in the mouth, si- 

 nuses, orbital region, pharynx, esophagus, 

 crop and even the proventriculus. They do 

 not involve the digestive tract beyond the 



