Reference to the causes which have been indicated will at once suggest that the remedies required may be purely local, or constitutional, or a combination of the two. In the case of purely local affections, such as the irritation excited by irritants, erythema, simple eczema, and parasitic diseases, local applications will usually suffice, although even in such cases it will have to be borne in mind that the state of the system will materially influence the progress of the disease, and certain changes of diet, or regulations as to exercise and work, may be expedient, if not absolutely necessary. All forms of skin disease which come under the head of acute specific disorders - variola, horse-pox, urticaria from indigestion, medicinal rashes, lead poisoning, nerve diseases, and others of a like kind - will be dealt with by constitutional means; the employment of local remedies will be admissible as palliatives, as, for example, where the itching from medicinal rashes, neurotic diseases, sympathetic pruritus, or urticaria ab ingestis renders the animal restless and sometimes prevents it from taking its food.