120 



OTHER FLAGELLATES 



Diagnosis : Giardia infections can be 

 diagnosed by recognition of trophozoites 

 or cysts in stained fecal smears. Fixation 

 with Schaudinn's fluid and staining with iron 

 hematoxylin are recommended. Tropho- 

 zoites alone are generally found in diarrheic 

 stools. The cysts can be concentrated by 

 the flotation technic. Zinc sulfate solution 

 should be used for flotation; sugar and 

 other salt solutions distort the cysts and 

 make them unrecognizable. 



Cultivation : Neither G. lamblia nor 

 any other species of Giardia has been cul- 

 tivated in artificial media. Karapetyan 

 (1960) cultured it in chicken fibroblast 

 tissue cultures along with the yeast, Can- 

 dida guillierniondi. The protozoon did not 

 develop without the yeast, which led him to 

 believe that there may be a synergistic re- 

 lation between the 2 organisms. 



Treatment : Giardia infections in man 

 can be successfully treated with either 

 quinacrine or chloroquine. Three oral 

 doses of 0. 1 g each are given daily for 5 

 days. Amodiaquin is considered even 

 better than these (Lamadrid-Montemayor, 

 1954); a single dose of 0. 6 g is given to 

 adults. 



Prevention and Control: These de- 

 pend on sanitation. Cerva (1955) found 

 that 2 to 5% phenol or lysol would kill G. 

 lamblia cysts, but that chloramine, mer- 

 curic chloride, formalin and a number of 

 other disinfectants were ineffective in the 

 concentrations commonly used. The cysts 

 were killed by temperatures above 50° C 

 and, after 10 hours, by freezing below 

 -20° C. They remained viable in water 

 for over 3 months. 



GIARDIA CANIS 

 HEGhfER, 1922 



Host: Dog. 



Location : Duodenum, jejunum, upper 

 small intestine. Tsuchiya (1932) found 

 the optimum location to be 10 to 30 inches 

 posterior to the stomach in puppies on a 

 carbohydrate diet and 25 to 40 inches 

 from the stomach in puppies on a high 

 protein diet. 



Geographic Distribution : North 

 America (United States, Canada), South 

 America (Uruguay). 



Prevalence : Catcott (1946) found G. 

 canis in 17. 7% of 113 dogs in Ohio. Cho- 

 quette and Gelinas (1950) found it in 9.0% 

 of 155 dogs in Montreal, Canada. Craige 



(1948) found it in 8. 8% of 160 dogs in Cal- 

 ifornia. We have seen it a number of 

 times in dogs in Illinois, but have not at- 

 tempted a survey. 



Morphology : The trophozoite is 12 

 to 17 ;j long and 7 to 10 ji wide. The me- 

 dian bodies are curved bars of the duoden- 

 alis type. The cysts measure 9 to 13 by 

 7 to 9 fi . 



Pathogenesis : The pathogenicity of 

 G. canis for the dog has still to be incon- 

 trovertibly determined. Catcott (1946) 

 noted diarrhea in one-third of his positive 

 dogs. Craige (1948) found Giardia in 17 

 of 71 dogs with dysentery, but in 13 of them 

 other organisms which he considered path- 

 ogenic were also present. Choquette (1950) 

 found Giardia in several cases of dysentery, 

 but some of these were complicated by 

 other conditions. Tsuchiya (1931) reported 

 that diarrheic stools alternated with formed 

 stools in a number of experimentally in- 

 fected puppies, but was uncertain whether 

 it was due to an existing pathological con- 

 dition or to the flagellates. According to 

 Tsuchiya (1932), a carbohydrate diet is 

 more favorable for G. ca)iis than a high 

 protein diet. 



Diagnosis : Same as for G. lamblia. 



Treatment : Quinacrine has been 

 found effective against G. canis. Craige 



(1949) gave dogs 50 to 100 mg twice daily 

 for 2 or 3 days, repeating if necessary 

 after 3 to 4 days. Choquette (1950) gave 

 large dogs 0. 2 g three times the first day 

 and twice a day for 6 more days; he gave 

 small dogs 0. 1 g twice the first day and 

 once a day for 6 more days. Chloroquine 

 has also been found effective in man; 0. 1 

 g is given 3 times a day for 5 days. 



Prevention and Control : The standard 

 sanitary measures should be used in pre- 

 venting the transmission of Giardia. 



