UNITED STATES 



DEPARTMENT of AGRICULTURE 



DEPARTMENT CIRCULAR 338 



Waflhinetnn D C Issued May 192S 



W Bsningion, JJ.V. Revised June 1934 



PARASITES AND PARASITIC 

 DISEASES OF DOGS^ 



By Mauhice C. Hall, chief, Emmett W. Price, parasitologist, and Willai(d 

 H. .Wright, associate veterinarian^ Zoological Division, Bureau of Animal 

 Industry * 



CONTKNTS 



Page 



Ipiportance of parasite control 1 



External parasites and parasitic skin diseases - 3 



Mange _ 3 



Chig^er infestation 11 



Tick infestation 11 



Louse infestation ___^__ 13 



Flea infestation ...1.. 16 



Page 



: Internal parasites and diseases due to them. . . 17 



Boundworict Infestation 18 



.Hookworm infestation (kennel anemia)— .20 



Whipworm infestation— 24 



Heart-worm infestation — 25 



, Tapeworm infestation ._ 27 



Fluke infestation 31 



Tongueworm infestation - 32 



Coccidiosis 33 



Canine piroplasmosis - 34 



IMPORTANCE OF PARASITE CONTROL 



The parasitic diseases of dogs and cats rank in importance with the 

 bacterial diseases affecting these animals. No such provisions exist 

 for collecting statistics on diseases of animals as there are for collect- 

 ing statistics on diseases of man, so it is not possible to make such 

 close approximations as to prevalence of disease in veterinary medi- 

 cine as m human medicine. But conceding first place to distemper, 

 that almost universal scourge of dogs with its mortality commonly 

 estimated by veterinarians at about 50 percent, the various forms of 

 mange are probably entitled to a second position, with a group of 

 worm infestations following in imj)ortance. Worm infestations, 

 especially roundworm and hookworm infestations, are especially pre- 

 valent and deadly in puppyhood and most so in tropical and subtrop- 

 ical countries, although by no means unimportant in temperate 

 zones. There are a large number of worm parasites and of external 

 parasites, such as insects and ticks, reported from dogs and cats, but 

 only a few of the more important ones are considered here. 



The importance of these parasites, especially those of dogs, is 

 heightened by the fact that a number of them are transmissible in 

 some form to man and to livestock. A number which occur as 

 adults in the digestive tract of the dog also occur ia the same form 

 and in the same place in man. In addition dogs have a number of 

 adult parasites which occur as larval or immature parasites in man 



1 This circular, as revised, includes information on parasites affecting cats, 

 39851°— 34 1 



