THE ORGANS OF SPECIAL SENSE. 241 



liness of the dog and his kennel, washing the latter out 

 with hot water and turpentine, and pine-dust bedding, 

 frequently changed, are necessary. 



Lice, pediculi, cause less irritation than fleas, but look 

 much more objectionable. They affect especially certain 

 parts of the body, such as around the anus, at the junction 

 of the thighs, on the back, and inside the ears. They are 

 the concomitant of dirt and can be got rid of by cleanliness 

 strictly enforced. Mayhew suggests a dressing of the 

 whole body surface with castor-oil. Hill prefers the 

 ammonio-chloride of mercury, either as a powder brushed 

 into the coat, or as an ointment applied thoroughly and 

 left on for five or six hours, the animal being muzzled 

 during that time. 



The Dermatophyte Diseases of the Dog, or those due 

 to vegetable parasites, are two in number of importance 

 from a clinical point of view. The general principles 

 which guide us in the treatment and prevention of animal 

 parasitic diseases of the skin apply also with regard to 

 these disorders, but it is found that some agents are 

 specially well suited to destroy vegetable parasites, and 

 that the latter spread much less rapidly than animal para- 

 sites and cause much less irritation and constitutional dis- 

 turbance. The vegetable parasites are fungi, and, as such, 

 are mainly made up of spores and hyphal elements ; they 

 invade the epithelial constituents of the skin, and conse- 

 quently we find that in the vegetable parasitic diseases 

 fungal elements may be detected in hairs examined under 

 the microscope. These diseased hairs often are obstinately 

 retained in position while all around are shed and they are 

 enlarged and friable, breaking off irregularly. The der- 

 matophyta especially prevail in damp weather, ill-drained 

 kennels, and among young animals, also the absence of 

 cleanliness and want of sufficient food predispose, but con- 

 tagion is essential to communication of the disease. The 

 parasite may be obtained from other species than the dog, 

 and may also be transmitted to other animals, such as 

 mankind. The communication may be mediate or imme- 

 diate, and evidence tends to support the belief that the 



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