If it is Summer, it is also “Hot Spot” Season!

Hot spots or acute moist dermatitis is often associated with the summer months where a moist bacterial infection results secondarily to skin trauma, a result of a primary cause. The primary causes are typically:

• Allergies
  • Flea atopy (common)
  • Contact irritant
  • Food-related atopy
• Otitis externa (common)
• Insect bites
  • Flies (more severe cases can end up with maggots from egg laying)
  • Ticks
  • Mosquitos
• Poorly kept coat
  • Matting of undercoat not shed properly (common)
  • Lack of ventilation to the skin
  • Improper drying of coat due to matting or poor air flow (can be associated with swimming)
• Trauma
  • Scratching
  • Clipper blade irritation or trauma
• Mange (both sarcoptic and demodectic mites)
• Other causes
  • Anal sac disease
  • Ringworm
  • Autoimmune disease
  • Drug reaction
  • Chemical contact irritants

The typical presentation of “Hot Spots”

Many owners present their dogs for examination not really appreciating the full extent of the problem.  The dog presents with a matted, red, crusty or oozing area that is generally very sensitive to the touch.  Some areas in the center can have hair loss if inflammation or self-trauma due to the intensity of the itch.  There may also be a foul odor associated with the area depending on severity.  These spots can expand quickly and are often located under the ear (otitis issues), or closer to hindquarters (associated with matting or flea allergy dermatitis).

Hot spots almost exclusively are a dog issue and are rarely seen in cats.   It is seen predominately in dogs with a thick undercoat like golden retrievers, Labrador retrievers, German Shepherds, and Saint Bernards.  Another breed that seems to be prone to hot spots is the Rottweiler.   It is more commonly seen in young dogs (<4years old) and both sexes are equally represented.

Initial management of “Hot Spots”

The initial goal is to understand the full extent of the lesion, so proper cleaning and debridement is paramount.   However, given the painful nature of the lesion(s) the dog may need sedation or general anesthesia may be required to properly clip the surrounding hair and to thoroughly cleanse the affected area.   Removal of crusts and exudate is also important to allow proper drying of the area and usually can be done with a clean damp washcloth soaking the crusts to help facilitate removal followed by gently wiping away any exudate.   Once cleaned, the skin can be rinsed with a mild antiseptic such as a chlorhexidine (or similar) solution.

Treatment of “Hot Spots”

With the cleaning completed the full extent and severity of the trauma can be assessed and a plan of treatment instituted.  Treatment plans often include a combination of the following:

• Minimizing the itchiness
  • Breaking the itch cycle is key to reducing further trauma. Products that help this are:
    • Topical steroids
      • Sprays: help cover a larger area but try to avoid those products containing alcohol that can sting.
      • Cremes:  can be more soothing to affected areas but may need time to “vanish” or dog may just lick off if the area is not protected.
    • Topical anesthetics
      • 5% lidocaine or 1% pramoxine help minimize itch but their effects can be short lived.
    • Oral steroids
      • Prednisone can help if used for short period of time (5-10) days.
      • Side effects of oral steroids can be increased hunger, water consumption, and frequency of urination. Additionally, some dogs will pant more when taking oral steroids.
    • Apoquel® (Oclacitinib) has also been used to break the itch cycle in dogs without the side effects seen with oral steroids.
  • Topical drying agents
    • Burrows’s solution or 2% aluminum acetate solution can help decrease oozing of the affected area thereby reducing further crust formation, which can provide an environment for further infection to propagate.
  • Topical antibacterial products
    • Many products contain a combination of an antibacterial agent with a corticosteroid making it easy for the owner to apply two agents with one treatment.
      • Antibiotics: Such as gentamycin, neomycin, etc.
      • Enzymatic antibacterial:
        • Given the concern about antibiotic resistance, ZYMOX® Topical Cream and Spray with or without 1% hydrocortisone provides enzymatic antibacterial activity without fear of potentiating antibiotic resistance.  They also do not sting when applied.  
      • Oral antibiotics
        • Depending on the severity of dermatitis, oral antibiotics may be needed for 2-3 weeks to help eliminate bacterial infection.
      • Elizabethan-type collar
        • Helping to reduce licking or biting, an Elizabethan collar is used to physically prevent the dog from getting at the lesion during healing.

Treating the primary issue:

Of course, treating the “hot spot” itself is only treating the secondary result of the primary cause.  The pet owner should always be advised to monitor the dog and treat any known primary issues that may incite a “Hot Spot”.   Some of these preventative/maintenance items would include:

• Proper grooming and brushing: Eliminate excessive undercoat, especially during times of shedding to help the skin to breathe, reduce the heat level and to prevent direct skin irritation.
• Flea and tick control: There are multiple products that are very effective to eliminate fleas, ticks, and other biting insects, which can cause direct irritation and may induce an allergic reaction.
• Proper ear care: Maintaining a healthy external ear canal will help dogs prone to ear infections stay healthy and reduce infections and secondary scratching or rubbing of the ear area. Using products like ZYMOX ear cleanser weekly helps maintain a natural ear pH, enzymatically reduces bad bacteria, and removes any debris.
• Manage allergies: If the dog has known allergies, then using products such as Apoquel, Cytopoint® and/or hypoallergenic foods, where appropriate will help reduce the dog’s tendency to scratch and cause trauma.
• Regular veterinary consultations: Of course, many other things including those mentioned above can be the primary culprit initiating a “Hot Spot, so regular veterinary consultations are recommended to help root out those primary issues before they cause even more problems.

“Hot Spots” need not be a part of every dog’s summer, but with proper prevention and a quick response, if issues arise, they can be minimized to keep dogs happy all summer long.