PAEASITES AND PAKASITIC DISEASES OF DOGS 15 



Dalmatian, Caucasian, or Oriental insect powder), allowing it to 

 remain on for half an hour or so, and then combing or brushing it 

 out, with the dead and stupefied lice, on to a newspaper, the paper, 

 lice, and powder then being burned. This treatment must be re- 

 peated a number of times m order to keep down the lice. Other 

 powders, containing sUch insecticides as naphthalene, sulphur, and 

 tobacco, may be used in the same way. 



Experiments indicate that derris powder, when fresh, is effective 

 for the destruction of lice on dogs and cats. It is used in the pro- 

 portion of 1 part of derris to 2 parts of flour or corn starch, the mijrture 

 oeing thoroughly dusted into the hair. Pyrethrum powder also may 

 be used for the destruction of lice on cats. As previously stated, 

 coal-tar creosote preparations or other preparations containing phenol 

 should not be used on cats. 



When onljr biting lice are present they may be destroyed by dusting 

 sodium fluoride into the hair and leaving it on, the animal not being 

 washed for the ne^t 

 10 days. One appli^ 

 cation will usually 

 destroy all the lice. 

 The animal should be 

 prevented from lick- 

 ing itself, as 1 gram 

 (about one-fourth tea- 

 spoon) of sodiiun flu- 

 oride will kill a dog of 

 average size. This 

 chemical is not of 

 value against sucking 

 Uce. 



FLEA INFESTATION 



Cause.— In the 

 United States there 



orp frnTT QnppiAG nf Figure 12. — The dog flea, Ctenocephatus canis. Female. Lateral 

 are lOUr species _0I ^j^^ Enlarged. From Martini, 1923. 



fleas which are ot in- 

 terest as parasites of dogs and cats. These include two very similar 

 species, called respectively the dog flea, Ctenocephalus canis, and the 

 cat flea, C Jelis, the other two being the common human flea, Pulex 

 irritans, and the sticktight or chicken flea, EcMdnophaga gallinacea. 

 The dog flea (fig. 12) appears to be the most common flea attack- 

 ing dogs and people in the eastern portion of the United States. 

 It moves about on the host animal between feeds, transfers readily 

 from dog to dog and from dog to man, but is disposed to remain 

 on some host animal rather than off. The eggs laid by the flea fall 

 off the host animal and in the course of time hatch, giving rise to 

 elongate larvae which feed on the animal and vegetable content of 

 the trash present in the dog's bedding or in other places frequented 

 by dogs. In time the larva forms a sort of cocoon, and after a period 

 in the pupal stage the insect emerges as an adult flea. In the house 

 the development from egg to adult commonly takes place in carpets 

 and rugs, and in the trash in cellars and basements. The closely 

 related cat flea has a similar habit and life history. 



