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THE TRICHOMONADS 



proventriculus. They often occur in the 

 liver and to a lesser extent in other organs, 

 including the lungs, air sacs, heart, pan- 

 creas, and more rarely the spleen, kid- 

 neys, trachea, bone marrow, navel re- 

 gion, etc. 



The early lesions in the mouth are 

 small, yellowish, circumscribed areas in 

 the mucosa. They increase in number and 

 become progressively larger, finally de- 

 veloping into very large, caseous masses 

 which may invade the roof of the mouth and 

 sinuses and may even extend thru the base 

 of the skull to the brain. The early lesions 

 in the pharynx, esophagus and crop are 

 small, whitish to yellowish caseous nod- 

 ules which also grow. They may remain 

 circumscribed and separate, or they may 

 form thick, caseous, necrotic masses 

 which may occlude the lumen. The cir- 

 cumscribed, disc-shaped lesions are 

 often described as "yellow buttons". Those 

 in the esophagus and crop may have central, 

 spur-like projections. A large amount of 

 fluid may accumulate in the crop. The le- 

 sions in the liver, lungs and other organs 

 are solid, yellowish, caseous nodules 

 ranging up to a centimeter or more in di- 

 ameter. 



In the turkey and chicken, the lesions 

 occur mostly in the crop, esophagus and 

 pharynx, and are relatively uncommon in 

 the mouth and liver. The lesions in the 

 mourning dove are similar to those in the 

 pigeon. 



Immunology : As mentioned above, 

 different strains of T. gallinae differ 

 greatly in virulence (Stabler, 1948; Flor- 

 ent, 1938; Gloor, 1943). Previous infec- 

 tion bestows more or less immunity; adult 

 pigeons which have survived infection as 

 squabs are symptomless carriers. Infec- 

 tion with a relatively harmless strain pro- 

 duces immunity against virulent strains 

 (Stabler, 1948a, 1951). According to 

 Florent (1938), pigeons are particularly 

 susceptible at the time of weaning and of 

 the first molt. Stabler (1953) found that 

 immunity did not increase with age of un- 

 infected birds. Certain breeds or strains 

 of birds may be more sensitive than others. 

 Miessner and Hansen (1936) felt that roller 



and tumbler pigeons were such, and Levine 

 and Brandly (1940) were able to infect 

 chicks from one source readily while chicks 

 from other sources were very resistant. 



Epidemiology : In pigeons and mourn- 

 ing doves, trichomonosis is transmitted 

 from the adults to the squabs in the pigeon 

 milk which is produced in the crop. The 

 squabs are infected within minutes after 

 hatching. Hawks and other wild raptors 

 become infected by eating infected birds. 

 Turkeys and chickens are infected thru 

 contaminated drinking water. Feral pig- 

 eons and other columbid birds are the or- 

 iginal source of infection. The trichom- 

 onads pass into the water from the mouths 

 of infected birds, and not from the drop- 

 pings (Stabler, 1954). T. gallinae has no 

 cysts and is very sensitive to drying, so 

 direct contamination is necessary. 



Diagnosis : Upper digestive tract 

 trichomonosis is readily diagnosed by ob- 

 servation of the lesions together with dem- 

 onstration of the protozoa. It must be 

 differentiated from other conditions which 

 may cause more or less similar lesions, 

 including fowl pox, vitamin A deficiency 

 and moniliosis (thrush). 



Cultivation : T. gallinae can be cul- 

 tivated readily in any of the customary 

 trichomonad media. Diamond (1954) com- 

 pared 28 culture media for it and (1957) 

 introduced a trypticase-yeast extract- 

 maltose-cysteine-serum medium for it and 

 other trichomonads. 



Treatment : A number of workers 

 have recommended the use of copper sul- 

 fate for 20 days or more in the drinking 

 water to eliminate T. gallinae (see Stab- 

 ler, 1954) but this is not particularly sat- 

 isfactory. The optimal concentration for 

 non-breeding pigeons is 1-1000 and that for 

 breeding pigeons with squabs is 1-3000 

 according to Jaquette (1948), but it tends 

 to make the birds sick, and Jaquette felt 

 that all the treated birds may have suffered 

 liver damage. Turkeys will not drink 

 1-2000 copper sulfate. 



The best treatment for T. gallinae is 

 2-amino-5-nitrothiazole (enheptin). 



