Hot spots on Dogs (aka pyotraumatic or moist dermatitis)
What are they?
A hot spot is a rapidly growing area of infection on your dog’s skin. They are moist, reddened and will ooze. Often a dried crust forms in the hair over the wound and can hide the extent of the skin damage underneath.
A hot spot always comes secondary to another cause. These can include fleabites, skin allergies, moist skin folds, small scratches or grooming cuts, and anything else that compromises intact and healthy skin. Once infection is established (usually Staphylococcus bacteria), the hair coat helps to trap ooze, keeping the skin moist and allowing crusts to form from dried pus.
The hot spot quickly gets larger from the infection and scratching. This one below an ear is already 5cm by 7cm and could double in size by tomorrow.
Microscopically your vet will see numerous inflammatory cells called neutrophils. These are the main ingredients of pus. (The purple blobby cells below). Bacteria are often also seen.
Hot spots are usually very painful and can easily double in size each day they are left untreated. This is why it is important for your dog to see the vet for this type of skin condition.
It is likely your dog will need a course of oral antibiotics and corticosteroids to treat the bacterial infection present and relieve pain and itchiness. It is helpful to treat the hot spot by clipping the hair on and around the wound, cleaning, and disinfection. By the time the vet sees your dog, the hot spot is often incredibly itchy and painful and it may be necessary to sedate your pet to initially clip and treat the wound. Your dog may have to wear and Elizabethan Collar for a few days to stop further trauma of the skin.
Understanding the underlying cause of the hot spot is key in prevention or catching them early. Ensure your dog is on regular flea and tick prevention, good management of ongoing allergies or skin problems, preventing licking of wounds or areas of irritation by putting an E-collar on your dog are all good methods of hot spot prevention. Dogs with chronic skin flare-ups may benefit from keeping their coat short during the warm summer months.