Dr. Louis N. Gotthelf (member American Academy of Veterinary Dermatology)
Montgomery Pet Skin and Ear Clinic
3310 Atlanta Highway
Montgomery, AL 36109
A “Hot Spot” is a painful area of the skin that is weeping serum and pus. The medical term for a hot spot is acute moist dermatitis. The serum is very irritating to the skin and so the dog will itch and scratch at it more, which causes more leaking of serum onto the skin. In a thick coated dog, the wet hair is in contact with the skin and actually burns the skin underneath. The hairs growing in the hair follicle are dissolved by chemicals in the serum, which causes the hair to fall out.Hot spots can occur very rapidly. They are usually found on the cheek area or on the rump, but they can be found anywhere on the dog's body. A hot spot is a large moist, warm area where the hair has come out and the dog is very itchy
Most hot spots are the result of allergies. The dog will have the itching sensation at a particular area because of allergic skin disease and that causes the dog to scratch at the itch. Once the skin is traumatized, that causes the area to itch more. This is called the itch-scratch-itch cycle. Left untreated, these areas are great bacterial breeding grounds and the result is that the skin will produce pus to combat the bacterial infection.In order to treat a hot spot it is important to clip the hair around it until the underlying skin is normal. This can be a large area in many cases. Then the skin is washed daily to remove the serum from the skin. After the skin is cleaned, a topical antibiotic/steroid medication is applied to decrease the bacterial infection and to soothe the allergic skin. It can take a week or so to begin the healing process. The area will scab up and the weeping will stop. At this point the topical medication can be stopped. As healing proceeds, hairs will regrow out of the hair follicle and there will be stubble felt on the skin. Sometimes the hair will grow out a different color than the rest of the dog's hair.
Because most hot spots are the result of some type of allergic skin disease, the underlying allergy needs to be treated to prevent future hot spots. Your veterinarian will treat the allergy depending on the type of allergy (atopic dermatitis, flea allergy, food allergy, or contact allergy) your dog has.