84 



THE TRICHOMONADS 



The life cycle of trichomonads is sim- 

 ple. They reproduce by longitudinal binary 

 fission. No sexual stages are known. 

 There are no cysts, altho degenerating or 

 phagocytized individuals (or entirely dif- 

 ferent organisms such as Blaslocyslis) 

 have been mistaken for them. 



Genus TRITRICHOMONAS 

 Kofoid, 1920 



Members of this genus have 3 anterior 

 flagella. 



TRITRICHOMONAS FOETUS 



(RIEDMULLER, 1928) 



WENRICH AND EMMERSON, 1933 



Synonyms : Trichomonas utero- 

 vaginalis vilulae, T. bovis, T. genitalis, 

 T. bovinus, T. mazzanti. 



Disease : Bovine trichomonad abor- 

 tion, bovine genital trichomonosis. 



Hosts : Ox, zebu, possibly pig, 

 horse, roe deer. 



productive disorders in cows bred by in- 

 fected western range bulls may amount to 

 about S800 annually per infected bull. On 

 this basis, the 23 infected bulls they found 

 in their survey would cost their owners 

 about $18,000 a year. The annual loss due 

 to an infected bull in an artificial insemin- 

 ation ring would be considerably greater 

 than this. 



Morphology : The morphology of T. 

 foetus has been studied by Wenrich and 

 Emmerson (1933), Kirby (1951) and Ludvik 

 (1954), among others. The body is spin- 

 dle- to pear-shaped, 10 to 25/i long and 

 3 to 15|U wide. It has 3 anterior flagella 

 and a posterior flagellum which trails as 

 a free flagellum about as long as the an- 

 terior flagella. The undulating membrane 

 extends almost the full length of the body 

 and has an accessory filament along its 

 margin. The costa is prominent. The 

 axostyle is thick and hyaline, with a cap- 

 itulum containing endoaxostylar granules 

 and a chromatic ring at its point of emer- 

 gence from the posterior end of the body. 

 The parabasal body is sausage- or ring- 

 shaped. A cytostome is present. There 

 is no pelta. 



Location : Genital tract. 



Geographic Distribution : Worldwide. 

 Morgan and Beach (1942) mapped the geo- 

 graphic distribution of bovine trichomon- 

 osis. 



Prevalence : Altho T. foetus is 

 known to be widely distributed, few studies 

 have been made of its incidence. It is 

 especially common in southern Germany 

 and Switzerland, up to 30% of the cattle 

 having been found infected in some areas. 

 In the U. S. , it is probably third to brucel- 

 losis and leptospirosis as a cause of abor- 

 tion in cattle. In a survey of 383 beef 

 bulls in Utah, Idaho and Colorado, Fitz- 

 gerald et at. (1958) found 6% to be infected. 



The USDA Agricultural Research Serv- 

 ice (1954) estimated that bovine trichomon- 

 osis causes an annual loss of $750,000 in 

 the United States. This figure is probably 

 low. Fitzgerald et at. (1958) estimated 

 that losses in production because of re- 



Fig. 7. 



Tyilrichomonas foetus. X 3400 

 (From Wenrich and Emmerson, 

 1933, J. Morph. 55:193) 



Pathogenesis : A great deal has been 

 written about bovine trichomonosis. 



