What causes skin problems for dogs?

One major cause of skin problems in dogs is systemic Allergies, which can be to anything from fleas or ticks to foods like chicken or soybeans to environmental items like pollen or dust mites.

Another possibility is ectoparasites such as mites or lice; these are less common with the introduction of ivermectin which has reduced the prevalence of these parasites in developed countries. A major problem in domestic dogs in Western countries is Demodex mange, another ectoparasite.

A third possibility is skin infection, which in dogs tends to be bacterial and secondary to another problem.