Returning from camp, my daughter thought she might have poison ivy on the back of her leg. “Let me see” I said, expecting to find a small area of the classic poison ivy rash. Instead, there was a huge red patch, swollen and hot to the touch, more than seven inches across. It looked truly awful. “We’re going to the doctor,” I insisted, horrified.
I imagine this is how many a dog owner feels when their woofer, Wifi, develops the skin condition colloquially referred to as a hot spot. You know, those big red weeping sores that seem to appear overnight? The ones that make you feel like a neglectful parent?
Don’t blame yourself. Technically called “pyotraumatic dermatitis,” hot spots arise incredibly quickly. “Dermatitis” just means inflammation of the skin. Duh. “Pyo” refers to pus, the gooey stuff oozing from those sores. It’s the word “traumatic,” that gives us the clue to why hot spots start and progress so rapidly. Here’s what happens. Something makes Wifi itchy. He scratches or chews the affected area. In other words, he traumatizes the skin. Bacteria that are normal inhabitants of the skin can now establish a secondary infection. Wifi is even more uncomfortable. He licks, scratches, and/or chews even more and the cycle perpetuates. It’s like when you dig at that poison ivy rash until it bleeds, and then gets infected. Your mother was right when she said, “Don’t scratch!”
Hot spots occur most frequently in hot weather and are most often found under the ears, on the cheeks, or on the hips, rump, or thighs. They can present as one large spot, or multiple smaller lesions. The location can suggest the underlying cause. First, check for fleas. Although it is possible to have fleas all year round on the Vineyard, like tourists, they tend to peak in the summer. Fleas like to congregate along Wifi’s caudal dorsal midline. That means the top of his back, toward the tail. Hot spots on the rump or thigh are often associated with fleas. Check by using a very fine-toothed comb called a flea comb. Run it down his back to the base of his tail multiple times. Don’t just look for hopping critters. Look for tiny black specks. No, it’s not dirt from rolling in the driveway. It’s flea poop. If you don’t believe me, put it on a wet paper towel and watch as a rusty, red halo spreads around the black speck. Fleas eat blood, so flea poop will “bleed” on that damp paper towel. And where there’s flea poop, there are fleas. Check his groin and belly too. On dogs with very thick undercoats, fleas may gravitate to the less densely furred regions on the underside.
Next, check Wifi’s ears, especially if the hot spots are on his face, neck, or cheek. Look deep into the ear with a good light, not just on the inside of the flap. A healthy ear should be clean and dry. If you see redness, debris, or detect an odor, Wifi may have an ear infection and you should consult your veterinarian. Other things that may make Wifi itch include such things as pollen or food allergies, wounds, tick bites, hair matts, or chronically wet coats from swimming. Dogs who swim need to be rinsed off with fresh water to remove sea salt and pond scum. Towel dry him vigorously. If his ruff or pantaloons stay damp, you can even use a hair dryer judiciously, being careful not to burn him.
But sometimes, no matter what you do, Wifi ends up with a nasty hot spot. So now what? Treatment begins with gently clipping and cleaning the area. Be advised that although these infections are superficial, they are incredibly tender. Even the nicest dog may take exception to your touching it, no less coming at him with a pair of clippers. Do not get bitten. When in doubt, have your veterinarian do the job. It is not uncommon for a hot spot to be so sore that sedation is needed before we can clean it up, but getting the area open to the air is essential because it helps it to start to dry and heal. Do not use scissors. Really. It’s easy to inadvertently cut or stab a squirming patient. (Then you have a dog with a hot spot and a laceration.) Use clippers.
Next, we need to make Wifi stop self-traumatizing. There are products that can be applied topically that taste bad to discourage him from licking or chewing. Check with your veterinarian first. Some human medications contain things that are toxic when ingested, such as zinc oxide. Whereas people rarely decide to lick off topical ointments, Wifi has no such inhibitions. (Then you have a dog with a hot spot and zinc poisoning.) As someone who has trouble not scratching when I have an itch, I think it is unkind to use an Elizabethan collar on a dog with a hot spot without simultaneously doing something to relieve the discomfort. Our goal should be to stop the itching, not just to prevent the scratching. Oral antihistamines or corticosteroids can provide relief. Topical antibiotics are also used on superficial hot spots but about a third will have deeper infections, warranting oral antibiotics.
In case you were wondering, dogs do not react to poison ivy, so that’s not the cause of Wifi’s hot spot. Dogs are just not sensitive to urushiol, the oil in the ivy that gives humans that annoying rash. My daughter? She didn’t have poison ivy either. The doctor said it might just be a bacterial infection, but there was a small chance it was erythema migrans, the bull’s-eye rash sometimes seen in the early stages of Lyme disease in humans. (Dogs don’t get erythema migrans either, even though they do get Lyme disease.) In either case, a course of that magic doxycycline would help, along with topical corticosteroids to relieve the itching — and a mother to keep reminding her, “Don’t scratch!”