32 
GEORGE MULLER. 
We will consider diseases of the skin in the lower animals 
under the following heads : 
I.—Non-Parasitic Skin Diseases. 
1. —Erythema simplex. 
2. —Dermatitis erythematoza. 
3. —Eczema. 
4. —Prurigo. 
5. —Acne. 
6. —Pemphigus. 
7. —Urticaria. 
8. —Erysipelas. 
9. —Dermatitis gangraenescens. 
II.— Parasitic Skin Diseases. 
a. — Caused by Vegetable Parasites. 
10. —Alopecia. 
11. —Favus. 
12. —Herpes tonsurans. 
13. —Dermatitis Canadensis (Axe). 
14. —Stomatitis pustulata contagiosa. 
b. — Caused by Animal Parasites. 
15. —Scabies. 
16. —Acarus. 
17. —Dermatitis pruriginosa—(Rivolta). 
18. —Haematopihus and Trichodechtes. 
19. —Ixodes, Dermanyssus, Pulex, Simulia, Oestrus, Ochro- 
myia, Lucilia, Leptus. 
I.—Erythema Simrlex. 
This occurs in animals as an acute process affecting the entire 
integument, and is seen as a moderate hyperaemia of the upper 
layers of the corium. 
A hyperaemia of this kind may be caused by external irritants, 
such as traumata, chemicals, high or low temperatures—in short, 
by anything which can cause dilation of the blood-vessels and hy¬ 
peraemia of the skin. In dogs the irritation of ammoniacal urine 
often causes an erythematous eruption in the vicinity of the mea¬ 
tus. 
