466 NON-PARASITIC SKIN DISEASES 



at other parts can be readily pulled out. The skin of fowls, 

 when feathers have been plucked, appears apparently 

 healthy, as does that of rabbits which have pulled out the 

 fur. When due to wounds, scalds and burns the skin is 

 thickened, often scaly and the hair around the affected 

 area often distorted from its usual direction of growth, 

 appearing longer at the margins. 



Diagnosis. This is made by negative microscopic exami- 

 nation of skin scrapings, and inspection of skin for scars. 

 Observing or inquiring into the habits of the animal affected, and 

 a careful examination into its general condition are helpful. 



Differential Diagnosis. Alopecia must not be confused 

 with demodectic mange, which frequently causes loss of 

 hair in small but gradually enlarging areas, nor with the 

 depluming mite which acts similarly on fowls. 



Prognosis. Good if due to general nutrition disturbance. 

 If from scar formation the loss is permanent, as is also true 

 of trophic nerve disturbance. 



Treatment. Treatment consists in giving good food in 

 proper amounts, and stimulating metabolism by tonics, 

 especially those containing arsenic for its alterative action 

 on the skin. Scarified areas, if small, may be overcome by 

 complete removal of the areas and the healthy skin approxi- 

 mated by suturing. Feather pulling may be prevented by 

 allowing free range, or by using a device attached around 

 the upper half of the beak which prevents complete closing 

 but does not inconvenience the bird in eating or drinking. 

 Fur pulling of rabbits is not objectionable when their habits 

 are known. It may be overcome in part by supplying 

 proper material for bedding just before parturition. 



DERMATITIS. 



Definition. An acute or subacute, septic or aseptic 

 inflammation of the skin. It may be local or general. 



Etiology. Parasites. Probably more inflammatory con- 

 ditions of the skin in small animals are due to small parasites 



