28 



Circular 338, U. S. Department of Agriculture 



be infested with tongueworms should be destroyed on the ground 

 that they are carriers of parasites which are dangerous to man and 

 injurious to livestock. 



COCCIDIOSIS 



Fig. 31." E gg of 

 tongueworm. En- 

 larged. From 

 Koch, 1906 



Cause. — Coccidiosis in the dog is due to the presence and effects 

 of Tevj small jDrotozoan parasites. There are four species of these 

 parasites reported from dogs. Some of them occur in the epithelium 

 of the intestine and some of them under the 

 epithelium in the submucous connective tissue. The 

 parasites undergo certain developments in these 

 tissues and multiply here. Ultimately they de- 

 velop resistant forms called oocysts (fig. 32) which 

 pass out on the feces and serve to infect other dogs. 

 Symptoms. — In light infestations coccidia ma}^ 

 cause no perceptible symptoms in dogs, but in heavy 

 infestations diarrhea appears at the time when the 

 oocysts are passing in the feces and it may 

 be accompanied by the passage of blood and gas. 

 There may be a slight rise in temperature during this time. Under 

 unfavorable conditions, as in heavy infestations in very weak or 

 young dogs or those with secondary infections, the animals may 

 die. The diagnosis of coccidiosis depends on the finding of oocysts 

 in the feces. 



Treatment. — Xo effective treatment for coccidiosis in dogs is 

 known. However, the disease appears to be self-limited, all of 

 the organism.s present developing in the course of time to the oocyst 

 stage and passing out. From observations of 

 the writer this will probably occur, as a rule, 

 within two weeks. There is some evidence indi- 

 cating that an attack of coccidiosis confers some 

 subsequent immunity. The indicated treatment, 

 therefore, is along the lines of good care and 

 nursing, the animal being fed nourishing food 

 in quantities suited to its condition and protected 

 against unfavorable conditions until the infec- 

 tion terminates. Such symptoms as diarrhea 

 may be controlled by appropriate treatment if 

 necessary. The premises occupied by infected 

 dogs must be regarded as infected, and thor- 

 oughly cleaned; the use of strong, hot coal-tar 

 creosote dips appears to be of value. Heat and drying are destruc- 

 tive to ooc^^sts. As indicated in the introductory paragraphs, pre- 

 ventive measures for this disease and other parasitic diseases are 

 along the line of sanitation, and sanitary preventive measures are 

 primarily the business of the dog owner. In coccidiosis, as in the 

 other diseases, diagnosis and treatment are primarily the affair of 

 the veterinarian and the employment of a competent veterinarian 

 is always advisable when diseases are actuall}^ present. 



Fig. 32. — A dog cocci- 

 (lian. Jsospora rivolta. 

 Mature oocyst. En- 

 larged. From Wen- 

 yon, 1923 



O 



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