What Are Hot Spots?
Hot spots are one of those less then desirable skin irritations seen in dogs and other pets. Often, you'll hear your vet refer to them as moist dermatitis, but you ... well, you can call them hot spots.
Hot spots (also known as Summer Sores or Moist Dermatitis) can seemingly appear spontaneously anywhere on a dog's body; the surrounding area can rapidly deterioriate too. This moist, raw skin disorder has a variety of causes but the most consistent factor is bacteria.
What Causes Hot Spots on Dogs?
Hot spots occur when your dog itches, scratches or licks him or herself excessively, eventually forming a wet scab on the fur.
Anything that irritates or breaks the skin can create the environment for bacterial contamination if the surface of the skin has but only a little a bit of moisture on it. Such incidences of moisture can be such seeminly innocuous things such as as a recent bath, swim, stroll in the rain, or playtime in water. Even a slightly oozing sore can provide enough moisture and/or nutrient for a bacterial infection to take hold.
Although there are various types of "hot spot"-causing bacteria, most respond to oral and topical antibiotics. For some reason, cats rarely acquire hot spots. Because hot spots are usually very painful, it may be best for a veterinarian to treat your dog's hot spots, as clipping can cause more trauma if not done correctly.
How to Treat Dog Hot Spots
1. Trim the area around the hot spot with dog hair clippers. If the area is too big, shave it. Exposing it to air will dry out the moisture and help speed healing.
2. Clean the area with a mild water-based astringent or antiseptic spray, or specialized shampoo, and pat dry.
3. Apply hydrocortisone spray or hydrocortisone cream (with a veterinarian's prescription) to stop the itching and help promote healing.
4. Prevent your dog from biting, licking or scratching the hot spot affected area. Placing an Elizabethan collar (plastic cone) around your dog's neck, for example, can be an excellent tool to keep him/her from biting and licking at it.
5. Keep an eye on the area to make sure it continues to heal and doesn't worsen or spread. Hot spots often require a visit to the vet, who will likely prescribe topical medication usually in the form of a Gentamicin / Betamethasone spray, and possibly oral antibiotics. The vet may also give your dog a cortisone injection to jump start the healing process.
Below is a view of a minor Hot Spot. But even this little lesion could spread rapidly and become severe.
A Typical Hot Spot and Its Treatment
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In this photo we can see—now that the fur has been parted—the raw, weeping circular hot spot. These often spread under the cover of the fur so that by the time you notice them they are well established and spreading. This particular case of moist eczema may have been caused by a tick bite. The fur is shaved over the moist eczema to facilitate application of medication as well as to allow drying.
The area surrounding the hot spot lesion should be shaved. That tiny black spot at the top of the hot spot is an area where the skin has actually died and may be where a tick was attached. Why one tick will trigger moist dermatitis and others won't is still a mystery. If every tick bite caused this much reaction, the magnitude of skin problems in dogs would be staggering!
Daily cleaning of the hot spot, even every two hours for the first day or two, will speed up the healing. Also, any topical anti-bacterial ointment or dog hot spot products will arrest the growth of the bacteria. These skin lesions can take a week to finally dry and look like they are going to heal. Once they are no longer oozing, simply keeping the hot spot area clean will be all that's needed. The fur begins to grow back (sometimes a different color!) within two weeks.
This severe case of active moist dermatitis on a Golden Retriever (different from the case displayed above) shows how extensive the infection can be and the degree of damage a hot spot can do to the skin of a dog. This case has been shaved and cleaned; vigorous treatment with antibiotics and cleansers is started. Rarely will a scar be a consequence of Hot Spots but scarring can happen.