Allergies are a common problem in pets and can manifest themselves in various ways such as itchy skin, rashes or digestive problems. These reactions can be caused by allergies to food, pollen, moulds or fleas.

Infectious skin diseases in animals are often caused by bacteria, fungi, viruses or parasites. The most common infectious skin diseases in animals are pyoderma (bacterial skin infections) or dermatophytoses (fungal infections).

Autoimmune skin disease in animals is a condition where the body's immune system begins to attack its own skin cells and tissues. This type of disease manifests itself in a variety of ways, including rashes, ulcers, reddening of the skin and loss of fur. 

Parasitic skin disease in animals is caused by various parasites such as fleas, ticks, mites and nematodes that infest the skin, fur and claws of animals. These parasites can cause itching, skin redness, rashes and other unwanted symptoms.