“Hot spots,” also called acute moist dermatitis, are rapidly developing sores under the hair coat. They are common in thick-coated or long-haired dogs, less so in cats. They most often develop in areas where the hair coat is heavy, such as the back, tail base, and side of the thigh, neck, or face. Hot spots tend to occur more frequently in hot, humid weather. The dog often will scratch or chew at the area, although it can be quite painful (the condition is also called pyotraumatic dermatitis for this reason).
- Intense Scratching
- Intense Chewing
- Occasionally Accompanied with whimpering
- Skin is Moist and Reddened
- Pus-Like Discharge Coats the Skin
Hot spots begin with a superficial skin injury that causes some moisture to be caught under the hair coat. Bacteria grow in the fluid, causing more skin inflammation, and the affected area rapidly expands as more fluid oozes from the skin, promoting more bacterial growth. The speed of onset of hot spots is often striking, and a large and painful lesion can develop from previously normal skin in a few hours. Fortunately, other than being uncomfortable, hot spots are not life-threatening and they tend to heal very well.
Do not touch the hot spot directly with your fingers except to apply medication (and then, use disposable latex medical gloves). Touching a fresh hot spot can be painful and can carry bacteria into it, causing an infection. Call your veterinarian if you suspect hot spots. The ear will need to be properly cleaned and your pet will need to be prescribed an antibiotic to prevent infection. Expect that over the first 48 hours of beginning treatment, the hot spot will look “quieter”: less red, with less fluid oozing from its surface, and it should be less painful. Scabbing and return of normal skin usually occur over a 7-10–day period after that.
Keep your pet free of skin parasites, especially fleas. Groom long- or thick-coated pets regularly; remove foreign bodies such as plant material from the hair, so these do not cause mats nor penetrate the skin directly. Treat underlying skin diseases, such as allergies, if present.