llfi 



OTHER FLAGELLATES 



by 3/i. The two nuclei contain round endo- 

 somes 2/3 the diameter of the nucleus. 

 Anterior to each nucleus is a large blephar- 

 aroplast or group of blepharoplasts from 

 which 2 anterior and 1 anterolateral fla- 

 gella arise. Just behind this blepharoplast 

 is another from which the caudal flagellum 

 arises. The caudal flagella pass poster- 

 iorly in a granular line of cytoplasm to 

 their points of emergence near the poster- 

 ior end of the body. Hexamita moves ra- 

 pidly without the spiralling characteristic 

 of trichomonads. 



Fig. 17. Hexamita iiieleagridis. 

 (Original) 



X 2800. 



Life Cycle : Multiplication is by 

 longitudinal binary fission. Slavin and 

 Wilson (1953) and Wilson and Slavin (1955) 

 described what they believed to be schizog- 

 ony and cyst formation, but Hoare (1955) 

 considered their idea to be purely specu- 

 lative and inacceptable. 



Pathogenesis : Hexamitosis is a dis- 

 ease of young birds; adults are symptom- 

 less carriers. The mortality in a flock 

 may be as high as 70 to 80%, but heavy 

 losses seldom occur in poults over ten 

 weeks old. Affected poults appear nervous 

 at first, have a stilted gait, ruffled, un- 

 kempt feathers, and a foamy, watery 

 diarrhea. They usually continue to eat, 

 but chirp continually. They lose weight 

 rapidly, become listless, weak and finally 

 die. Birds often do not appear to be ill 

 until shortly before death, but examination 



will reveal that they are thin and have 

 lowered temperatures. Birds which re- 

 cover grow poorly, and an outbreak may 

 leave many stunted birds in its wake. 



The incubation period is 4 to 7 days. 

 Poults may die within a day after signs 

 appear. In acute outbreaks, the mortality 

 reaches a peak in the flock in 7 to 10 days 

 after the first birds die; in other flocks, 

 deaths may continue for 3 weeks. 



The principal pathological changes 

 are found in the small intestine. Catarrhal 

 inflammation with marked lack of tone is 

 present in the duodenum, jejunum and 

 ileum. The intestinal contents are usually 

 thin, watery and foamy, with localized 

 bulbous swellings filled with watery fluid. 

 The small intestine, especially the anter- 

 ior part, is inflamed and edematous. The 

 cecal contents are usually fluid, and the 

 cecal tonsils are congested. 



Epidemiology : Hexamita is trans- 

 mitted thru contaminated feed and water. 

 Carrier adult birds which have survived 

 earlier attacks are the most important 

 source of infection for turkey poults. 

 Sometimes the disease does not appear in 

 the earlier hatches but strikes the later 

 ones after the adults have been sold. This 

 may come about because the infections in 

 the earlier hatches were very light or per- 

 haps because the virulence of the strains 

 was too low to cause noticeable disease. 

 According to Hinshaw (1959) it may take 

 several passages in poults of a strain from 

 carrier turkeys before an acute outbreak 

 occurs. 



Wild quail, pheasants and chukar par- 

 tridges sharing the range with turkeys may 

 also be a source of infection. 



Hot weather and overcrowding may 

 also contribute to the severity of an out- 

 break. In addition, the role of flies de- 

 serves study. Turkey poults are excellent 

 fly-catchers, and these insects might carry 

 the protozoa from one pen to another. 



Diagnosis : Hexamitosis can be diag- 

 nosed by finding the protozoa in scrapings 

 from the small intestine, and particularly 



