OTHER FLAGELLATES 



115 



in California. In young poults it was pres- 

 ent thruout the intestinal tract, and in 

 adults in the region of the cecal tonsil. 

 Campbell (1945) found Coclilosonia in 

 large numbers in the intestinal tracts of a 

 flock of young turkeys in Scotland affected 

 with a disease clinically and pathologically 

 indistinguishable from infectious catarrhal 

 enteritis due to Hexa»iita meleagridis. 

 Both McNeil and Hinshaw and Campbell 

 considered the turkey form to be the same 

 species found in ducks, but experimental 

 and further morphological studies are 

 needed to be sure of this. 



It has not been established whether 

 this form is pathogenic for turkeys. 

 Campbell believed that it was the cause of 

 the enteritis which he saw, but Hexamita 

 was also usually detectable in his affected 

 birds. In the turkey poults studied by 

 McNeil and Hinshaw, Cochlosoma was al- 

 ways found in association with Hexamita 

 or with Hexamita and SalDionella. 



FAMILY HEXAMITIDAE 



Members of this family are bilaterally 

 symmetrical, with 2 nuclei, 6 or 8 fla- 

 gella and sometimes with axostyles and 

 parabasal bodies. Three genera are of 

 veterinary interest: Hexamita, Giardia 

 and Trepomonas. 



Genus HEXAMITA 

 Dujardin, 1838 



The body is piriform, with 2 nuclei 

 near the anterior end, 6 anterior and 2 

 posterior flagella and 2 independent axo- 

 styles (which may possibly be hollow tubes 

 rather than rods). The body is quite sym- 

 metrical, three anterior flagella and 1 

 posterior one arising on each side. Free- 

 living forms have 1 or 2 contractile vac- 

 uoles. The cytostome is obscure if pres- 

 ent. Some species form cysts. Some 

 members of this genus are free-living, 

 while others are parasitic in insects, 

 other invertebrates and all classes of ver- 

 tebrates. The taxonomic relations of the 

 various species are greatly confused, and 

 much work is needed before they will be 



understood. Reasons why some workers 

 use the spelling Hexamitus are given by 

 Kirby and Honigberg (1949). 



HEXAMITA MELEAGRIDIS 

 McNEIL, fflNSHAW AND 

 KOFOID, 1941 



Disease : Hexamitosis, infectious 

 catarrhal enteritis. 



Hosts : Turkey, peafowl, California 

 valley quail, Gambel's quail, chukar par- 

 tridge, ring-neck pheasant, golden pheas- 

 ant. See Levine, Beamer and McNeil 

 (1952) for references. H. meleagridis 

 has been transmitted from the turkey to 

 the chicken, quail and domestic duck, and 

 from the ring-neck pheasant, quail and 

 chukar partridge to the turkey. 



Location : Duodenum and small in- 

 testine of younger birds; some occur in 

 the cecum and bursa of Fabricius, espe- 

 cially in adults. 



Geographic Distribution : United 

 States, Canada, Great Britain, South 

 America (Uruguay). The distribution of 

 hexamitosis in California has been dis- 

 cussed by Hinshaw, McNeil and Kofoid 

 (1938). It has been reported from Con- 

 necticut by Jungherr and Gifford (1944), 

 from Indiana by Doyle, Cable and Moses 

 (1947), from Virginia by Farr, Wehr and 

 Jaquette (1948), from Alberta by Vance 

 and Bigland (1956), from Scotland by 

 Campbell (1945) and from England by 

 Slavin and Wilson (1953). It also occurs 

 in Illinois. 



Prevalence : The published reports 

 of outbreaks of hexamitosis are too few to 

 give a true picture of its importance. It 

 occurs in all major turkey producing areas 

 in the United States and in other countries 

 as well. It appears to be particularly im- 

 portant in California. The U. S. Dept. of 

 Agriculture (1954) estimated that it causes 

 an annual loss of $667,000 in turkeys in 

 the United States. 



Morphology : The body is 6 to 12/i 

 long and 2 to 5/j, wide, with a mean of 9 



