PARASITES AND PARASITIC DISEASES OF DOGS 13 



its mouth parts in the dog's skin and sucks blood, and this loss of 

 blood, a relatively unimportant matter in a light infestation with 

 ticks, becomes a serious matter in a heavy infestation. Certain ticks 

 are capable of causing a rapidly fatal paralysis, and cases of the sort 

 have been reported in dogs. Other ticks carry diseases from one 

 animal to another, as in the case of the cattle-fever tick, which carries 

 tick fever of cattle in the Southern States. The brown dog tick of 

 this country carries a disease — canine piroplasmosis — which is very 

 similar to tick fever. The American dog tick has been shown to 

 transmit the eastern form of Rocky Mountain spotted fever of man. 



Treatment. — The simplest control measure and one wbich is usually 

 applicable consists in the removal of the ticks by means of the fingers 

 or with forceps. Occasionally the mouth parts of the tick will be left 

 in the skin and may form festering sores, but this does not occur 

 very often . The control of ticks by hand picking is a time-consuming 

 process, however. For tnis reason, considerable search has been made 

 for an insecticide which would be effective for the destruction of the 

 parasites and yet safe for the host. It has been reported that an 

 extract of pyrethrum flowers containing a uniform and definite per- 

 centage of active ingredients is effective for the destruction of the 

 brown dog tick. Such preparations are marketed under proprietary 

 names. A stock solution is made by mixing 1 part of the pyrethrum 

 extract with 3 parts of a solution of \){ pounds of green soap dissolved 

 in one-half gallon of water. To this combined solution is added water 

 sufficient to make a dilution of 1 part pyrethrum extract in 19 parts 

 of the soap-and-water solution. The solution is applied by means 

 of a sponge until the coat of the animal is thoroughly saturated with 

 the liquid. This preparation is said to kill larval ticks almost imme- 

 diately. It is reported that engorged females five for a day or more 

 after treatment, but finally succumb. 



A 5- to 7-percent solution of pine-oil disinfectant has been recom- 

 mended for the destruction of the brown dog tick. The use twice 

 weekly of a powder containing 3 percent of rotenone is reported to be 

 effective for the destruction of these ticks. The use of drugs or 

 chemicals for the destruction of ticks on cats is not recommended. 

 Where animals are exposed to reinfestation, the use of any treatment 

 can only be palliative. Effort should be made to rid premises of 

 ticks in various stages of development by spraying kennels and runs 

 with a hot coal-tar creosote solution or with a pyrethrum emulsion. 

 As the brown dog tick can five for months under favorable conditions 

 without feeding, this is a control measure of great importance. 



Whenever possible, dogs and cats should be kept out of tick- 

 infested woods and out of contact with tick-infested stray dogs. 



LOUSE INFESTATION. 



Cause. — The dog is commonly infested with two species of lice. 

 One of these is a sucking louse, the sort commonly present on mam- 

 mals, and the other a biting louse related to the bird lice. 



