Because of theire relative size fleas, lice, mallophaga and ticks have been familiar for centuries. During the 19th century skin disease began to be classified into either parasitic or non parasitic forms. Meticulous morphological descriptions and empirical comparisons, the relaying of information concerning contagiousness and contamination as well as the search for the appropriate classification and terminology are the trademarks of this period. At the same time non-parasitic skin disease, in particular eczema and other pussy lesions atttained a higher profile as their diagnosis became easier.

By the end of the 19th century sarcoptes mange had become the second most commonly identified canine disease, behind distemper. By the middle of the 20th century, mange began to take a back seat to eczema and demodicosis. In all probability, symptoms of disease caused by parasites of the epidermis have been known throughout the centuries, as well as dermatomycosis, acne and boils. Among the less common skin diseases but also mentioned in the literature are parasitic dermatitis (1883), acanthosis nigricans (1903) and actinomycosis (1888). Increased attention of the veterinary community in oncology becomes apparent towards the end of the 19th century. The possibility of making inferences concerning human neoplasms led to the dog becoming an interesting object for modelling the human condition. Next to mange, ear disease counts as one of the earliest recognised skin disease of the dog. For a long time obscure nomenclature existed, which remained in use until well into the 20th century.

The manifold and different ways of satisfactorily treating most of the skin diseases in order to demonstrate satisfactory results show very clearly that very complex pathobiological methods were employed.The therapy in the 19th century invariably included - aside from treatment with medication - a change in diet, often combined with purging and roborants with a simultaneous improvement in the conditions under which the animal was kept. Most of the medications were self- formulated or adopted from large animal practice. It was only at the beginning of the 20th century that medication began to be commercialised and mass produced. Powder, paste, cream or liquid medications were adapted to suit the indications of the disease. Astringent, absorbent, anaesthetic, antiphlogistic, antiseptic, keratolytic and anti-parasitic therapies were used.

Support for this development came through the increasingly changing attitude of the dog owners. Aside from the traditional keeping of dogs for working purposes (guarddogs, hunting, shepherding and watchdogs), animals were increasingly being kept in the cities as household pets. The closer the ties between man and hound - especially in physical terms - the more people became disturbed by permanent itching, unpleasant smells and restlessness. The price of medication became less of an issue than ease and simplicity of application, smell and degree of effectiveness.

After their introduction in the 1930th, the sulphonamides were increasingly used parenterally in cases of bacterial skin disease, joined in the following decade by penicillin. At the end of the 1940th also in Germany synthetic organic pesticides in the form of various DDT, HCH and organic thiophosphate preparations became available. From the beginning of the 20th century physical rather than chemical treatments such as quarz lamps, X-rays, mercury vapour lamps and ozone treatment became increasingly popular for dermatological purposes.

The purpose of this dissertation, which refers back to the previously mentioned aspects, was to make transparent the developments which formed the basis for the current dermatology of the dog with its opportunities and perspectives.