A sensation within the skin that provokes the desire to scratch is medically known as pruritus. This condition causes much distress to affected dog and as a result there is an irresistible urge to scratch and bite the skin. The itching sensation begins at the nerves of the skin due to a chemical reaction, travels to the spinal cord, then to the brain. The animal "recognizes" the itching sensation in the brain and responds by scratching, licking, or chewing. The condition is also an indicator of skin inflammation. In fact, the act of scratching itself may stimulate these inflammatory reactions in the skin and make the condition worse. When intense itching occurs, the skin becomes inflamed and skin lesions develop. If left untreated, these skin lesions may lead to a bacterial infection and spread to other areas of the skin.
Pruritus is the second most common condition after gastrointestinal disorders for which veterinarian consultancy is sought. An affected dog with pruritus may display symptoms such as
Inflammation of the skin
Hair loss (alopecia)