Reviewed and fact checked by Bruce Whittle, DVM
Pyotraumatic dermatitis is the medical term for what is commonly referred to as a “hot spot”, a localized skin infection. Hot spots can be caused by a dog self-traumatizing an area due to itching caused by flea allergy. Though we don’t often think of the skin in this way, it is actually the largest organ in the body and plays a huge role in protecting the rest of the body from insults. Part of this role is played by the vast quantity of immune system components just under the skin that are the first line of attack against potential invaders.
Why did my dog develop a “hot spot”?
A hot spot forms when a dog either scratches at an area, thus disrupting the protective layer of the skin or has matted hair that keeps the skin underneath moist. This damaged skin can then become infected. Although the skin is literally covered in normal micro-organisms, when the acidity changes due to inflammation, this population changes and some bad bacteria or fungi that are normally kept in check by the good micro-organisms get out of control and take over. Dogs that lay on rough surfaces such unfinished concrete can also traumatize the skin, leading to a hot spot.
What does a “hot spot” look like?
A hot spot is often noticed by an owner due to localized hair loss. The underlying skin will often be reddened due to inflammation. Many hot spots, if not caught early, will develop infections so you might see some pus covering the affected area. Because hot spots are inflamed, they usually itch so the dog will scratch at or rub the area thus creating more trauma and making the problem worse.
What is the treatment for a hot spot in a dog?
Treatment of a hot spot depends upon the severity. In mild cases, clipping of the hair to allow the underlying skin to dry out a bit along with gentle cleaning may be all that is necessary. When the condition is more advanced and there is a deeper infection, antibiotics may be warranted that will reach deeper layers that topical products cannot get to. Special shampoos containing anti-inflammatory or anti-microbial agents may be helpful to decrease scratching, which will make the condition worse. Though bandaging is not preferred due to its tendency to hold in moisture, sometimes it may be necessary to keep an animal from further traumatizing the affected area. However, the bandage must be applied well to prevent slipping or friction to the damaged area that will further the trauma.
Summary
Though a hot spot is not life-threatening unless it gets infected with a very nasty bacteria, it is, at the least, uncomfortable to the dog and can be painful in more serious cases. Careful daily examination of the hair coat will allow an owner to detect a hot spot before it becomes severe. Preventing matting of hair through frequent grooming in dogs with longer hair will also help. If your dog gets hot spots frequently, your veterinarian can help you determine if there is some type of management change you can make to prevent them or they may recommend testing to see if there is an underlying metabolic or immune problem that is suppressing the body’s normal defense mechanisms. As with most disease conditions, early detection and treatment of hot spots is much easier than when the condition becomes more advanced.
