Parasites and Parasitic Diseases of Dogs 11 



of sores with subsequent bacterial infection. Hunting dogs are 

 especially subject to attack, owing to exposure as they range over 

 chigger-infestecl territory. The chiggers attach most often about the 

 head, feet, and belly, causing scattering eruptions which may con- 

 tain pus. Chiggers usually attach singly, but a dozen or so some- 

 times attach at one point. Under favorable conditions they may be 

 seen with a hand lens, but as a rule chigger infestation in dogs would 

 be suspected from signs of itching coupled with a history of chigger 

 attacks on man at the same time and in the same vicinity. 



Treatment. — Sulphur ointment will destroy chiggers at the point 

 of attachment and in some cases appears to have a favorable eifect 

 on infected sores due to scratching the places attacked by chiggers. 

 Alcohol in free and repeated applications is also good. Solutions of 

 coal-tar creosote dips, in the strengths recommended on the labels for 

 dipping or washing dogs, may be used. Ammonia, sodium bicarbo- 

 nate, or dilute tincture of 

 iodine serve to alleviate the 

 itching. 



Flowers of sulphur has 

 been found of value in pre- 

 venting attacks on man b}^ 

 chiggers, and it is probable 

 that it would be of value in 

 protecting dogs if dusted 

 into the hair. The coal-tar ^^ o m * • ^ ^- , ^ +• , 



T ITT 1,1 Fig. 8. — The American dog tick or wood tick, 



creosote dips would doubtless Dermacentor variabilis. Left, engorged female; 



be of value for the same pur- SSk's,'?908 ^""""' ^''"'"- ^^'^^■^■^- ^^^^ 

 pose. Oil of tar or fish oil, 



applied diluted with alcohol, would probably be repellent but ob- 

 jectionabl}^ messy. The cultivation of ground and the clearing away 

 of underbrush and rank vegetation aid in keeping down chiggers. 



TICK INFESTATION 



Cause. — Various species of ticks will attack dogs and about 14 spe- 

 cies have been reported from the dog in North America. The more 

 important of these in the United States are the American dog tick 

 or wood tick, Dermacentor variahilis, and the brown dog tick, Rhipi- 

 cephalus sanguineus. 



The American dog tick (fig. 8) usually occurs as an adult tick on 

 dogs, the earlier stages (those of seed tick and nymph) occurring on 

 various small mammals. It attaches to various parts of the body, 

 but displays a preference for the ears. When fully engorged with 

 blood the female tick is almost half an inch long and of a bluish 

 color, with a reddish-brown shield with white markings on the back 

 near the head. This species occurs in the eastern half of the United 

 States, in parts of the west coast, and occasionally elsewhere in this 

 country. 



The brown dog tick (fig. 9) occurs on dogs as seed tick, nymph, 

 and adult. It frequently attaches inside a dog's ears, sometimes deep 

 in the ear canal. The young ticks are likely to be abundant in the 

 long hair on the neck, but any stage may occur on almost any part 

 of the body, including the spaces between the toes. In this country 

 this tick occurs in the South, being reported from Texas, Louisiana, 

 and Florida, but it may be found farther north. Its occurrence on 



