Pyotraumatic Dermatitis in Dogs

The pyotraumatic dermatitis may start out as your dog obsessively licking one spot on a paw.  You look at it a few hours later and you see a red, moist lesion has developed where he has been licking.  Many dogs develop a lesion like this at least once over their lifetime, but not all of them.  Each dog may have a different reason as the cause but they all can be treated similarly.  While it is not a life threatening condition, it can lead to a bacterial infection and will need prescription medication for treatment.  If addressed properly, his prognosis of recovery is good.

Pyotraumatic dermatitis, also known as a hot spot, can develop in a matter of hours.  The sooner you seek treatment for your dog, the easier his recovery will be.

Symptoms of pyotraumatic dermatitis may include:

• Persistent licking
• Persistent chewing
• Persistent scratching
• Pruritus 
• Alopecia 
• Lesions that become red, exudative, swollen, erythematous, moist 

These lesions typically start out small but then get larger and worse with self trauma. The most commonly affected areas include:

• Periaural 
• Dorsal region
• Dorsolateral region
• Lumbosacral region 

Types

Pyotraumatic dermatitis is also known as a hot spot or acute moist dermatitis.  It is a form of acute inflammation of the skin as well as exudation.  It is common to see this condition on dogs when the weather is hot, especially if your dog has long fur or thick coat.  You will often find your dog constantly and persistently licking the area in question which will only make it worse.

This condition is often caused by your dog chewing, licking, or scratching a specific area.  There is almost always an underlying cause to this condition such as flea bite hypersensitivity, ectoparasites, food hypersensitivity, contact dermatitis, otitis externa, ocular disease, and even anal sac disease.  It can occur anywhere on your dog’s body.  The initial licking can also even be caused by pain.  If your dog is experiencing pain in his “wrist” area, he may begin to lick at it.  He then continues to lick at it until it develops into a lesion and then he licks at it even more.

When you arrive at the veterinarian’s office, she will start her diagnostic process by collecting a verbal history from you.  Your veterinarian will need to rule out other possible causes that can produce a lesion with similar symptoms like the one he is presenting with.  For example, she will need to make sure it was not from a burn or from a recent trip to the groomer where he perhaps received accidental razor burn. The vet will check for fleas and other causes of similar lesions.  She will also want to know if you have fed him anything new lately, if he has had any changes in his routine or home that could cause stress, if he recently injured himself, or anything else information wise that may be helpful to know about his condition.  

She will then proceed with performing a full physical exam.  While it may be obvious where the lesion is and the symptoms it is causing your dog, she will want to do a full evaluation of his entire body system.  She may find subtle signs of pain or causes of his persistent licking.  She will check for evidence of parasites, palpate his joint and muscles, and give him an overall evaluation.

For a better look at the affected area and in order to clean it up, your veterinarian will want to clip and clean the area.  This will move excess fur out of the way to allow her a clear view of the lesion and to remove the long hair from the sensitive area to avoid it irritating the area which would in turn lead to more licking.  

In addition to diagnosing and treating the pyotraumatic lesion, you will also need to investigate the cause of the initial licking sequence. During her examination, if the veterinarian found evidence of fleas or other ectoparasites, she may explain why this may be causing his symptoms.  If he was sensitive in any of his joints or muscles, she may suspect pain as the cause.

Ideally, the best treatment involves treating the lesion, breaking the itch cycle, and removing the underlying cause.  If you treat the lesion but do not break the lick cycle, your treatments will be useless.  You must stop the need to lick and scratch in order to break the cycle.  You must also address the underlying cause.  Your dog may stop licking for a while, but if there is an underlying cause, it is only a matter of time before he begins again.  

In more severe cases, some dogs develop papules or pustules around the lesion.  This would need antibiotic therapy as it can be indicative of furunculosis and folliculitis.  She may send you home with an oral antibiotic.  She may also send you with medications to apply topically to the lesion itself.  

If ectoparasites are the cause of his symptoms, your veterinarian will suggest a type of flea prevention or other medication to take care of the parasites.  If pain is the cause of your dog’s initial licking symptoms, she may recommend pain medication to see if it will stop his licking and chewing.  In some cases, before sending you home with a pain medication, your veterinarian may suggest blood work to ensure your dog’s internal organ function is all within normal limits.  

Some clinics also have a cold laser that can be used as a form of treatment; this treatment is known as laser light therapy.  The light stimulates cell reproduction in the area you shine the laser light.  It also increases blood flow to the area to stimulate the region, it decreases inflammation, and it provides an analgesic effect.

As soon as you notice your dog developing a lesion as described above, it would be a good idea to take him to his veterinarian.  The severity of the lesion can develop quickly after initial breakthrough of the skin.  Depending how persistent your dog is, his lesion can develop after only one day of licking.  The longer you wait to get it evaluated, the worse the lesion will become and therefore, the longer it will take to completely heal.  By seeking treatment and receiving medications quickly, his prognosis of recovery is good.