By Ryan Llera, BSc, DVM; Lynn Buzhardt, DVM
What is a hot spot?
Canine hot spots are red, inflamed skin lesions also known as pyotraumatic dermatitis or acute moist dermatitis. These names accurately describe the inflammatory skin lesions exacerbated by scratching that appear quickly, ooze, and may contain pus. Hot spots can be found anywhere on a dog’s body, but the most common sites are head, legs, and hips. These painful, smelly sores may be very obvious or may be hidden beneath matted fur.
What causes a hot spot?
Hot spots are usually caused by self-trauma when a dog scratches an itchy spot so vigorously that he creates an open wound. Dogs scratch for many reasons but regardless of the cause, hot spots are bothersome. When a dog licks the sore spot, he irritates superficial nerve endings in the skin which stimulates more itching followed by more licking, biting, and scratching. This lick-itch-lick cycle is the basis for the self-trauma that causes hot spots. Hot spots can dramatically increase in size in a very short period of time. Pet owners may go to work after noticing a pin-point area of redness and come home at the end of the day to find a raw lesion the size of a pancake.
How are hot spots treated?
The goal in treating a hot spot is to stop the trauma and prevent the development of a deep skin infection, so the first step in treating hot spots is to stop the self-mutilation. But, how do you stop a dog from licking, biting, and scratching? Some options include:
- an Elizabethan collar (also known as an E-collar or cone) that stops the dog from chewing at the hot spot.
- covering the hot spot with a sock or bandage to act as a barrier.
- topical or oral steroids (prednisone is most commonly used) and antihistamines (diphenhydramine – brand name Benadryl®, cetirizine – brand names Reactine®, Zyrtec®) to reduce the itching. Consult your veterinarian before using any medications intended for humans as they are often toxic to dogs
Often, it takes a combination of all options to stop the trauma.
In the meantime, the underlying cause of the hot spot must be addressed.
- If the hot spot formed as a result of impacted anal glands, they will need to be expressed.
- If the cause is flea allergy, a flea control protocol beginning with a fast acting adulticide and continuing with a monthly product (Frontline® Plus, Advantage® or Advantix®, Revolution®, Nexgard®, Simparica®, Bravecto®) to control the entire flea life cycle will be needed.
- If arthritis is the culprit, your veterinarian may prescribe non-steroidal anti-inflammatory drugs (NSAIDs) such as meloxicam, carprofen, or deracoxib or other pain medications (gabapentin is a common choice).
- For inhalant or food allergies, your veterinarian can help you to begin avoidance or de-sensitization therapy and recommend a hypoallergenic food.
- For ear infections, the underlying yeast or bacteria will be treated.
- If boredom or behavioral issues are the reason the dog traumatizes himself, training and behavior modification, additional exercise and enrichment, and/or medications, such as antidepressants (fluoxetine, clomipramine, amitriptyline) may be the solution.
- If poor grooming is the cause, seek a professional that knows how to handle a pair of clippers.
Clipping the hair away from the hot spot and the surrounding area is crucial to a successful treatment plan. The hot spot will heal more quickly if the hair is removed so that the lesion can dry properly. Grooming may be painful so the dog may need to be sedated.
“The hot spot will heal more quickly if the hair is removed so that the lesion can dry properly.”
After clipping, the lesion should be disinfected with a chlorhexidine solution that kills bacteria. Topical antibiotics, desiccating sprays, and soothing reagents will be more effective when applied to a clipped, clean skin surface. Oral antibiotics and steroids/antihistamines may also be in order for serious hot spots.
How can hot spots be prevented?
Continued monitoring and treatment of the underlying cause should prevent future hot spots. Some dogs also benefit from seasonal grooming, as well as regular brushing and bathing.