Cats and Dogs can scratch and itch for number of reasons but all have the same end result – an ulcerated sore skin and hair loss. There are many reasons cats and dogs can have an itchy skin and these can be categorised into Allergic, Parasitic, fungal, yeast and bacterial causes:
Allergic causes (called hypersensitivity reactions) can be due to allergies to dust mites and pollens, this is called Atopic Dermatitis. Allergies can also develop to flea bites – Flea Bite Hypersensitivity; food items - Food Allergy / Adverse Food Reactions; and allergies to things coming in contact with the skin – Allergic Contact Dermatitis. Investigating allergic skin diseases involves diet trials, intradermal skin testing, and blood tests.