Skin Ulcers in Dogs

By Melissa Boldan, DVM on Oct. 30, 2023

What Are Skin Ulcers in Dogs?

Skin ulcers in dogs are deep sores or open wounds on the skin that often heal poorly on their own. They can be caused by anything that lowers blood supply to an area of the skin.

Skin ulcers can be grouped as either more erosive or ulcerative.

Erosions are shallow wounds on the skin, and ulcers are deeper wounds on the skin that are typically slower to heal.

Usually when ulcers occur, there is a problem with blood flow to that area or a source of chronic irritation to the ulcerated (broken) skin that stops it from healing.

Ulcers are often painful to the touch and may leak fluid or blood. It’s common for ulcers that were not originally caused by a skin infection to become infected.

Because there are so many different skin conditions that can lead to ulceration of the skin, it’s a common condition.

If your dog is eating and drinking OK and has normal energy, you can likely schedule your dog to be seen by their regular veterinarian.

However, don’t wait too long, as ulcers can quickly worsen and noninfected skin ulcers can become infected quickly.

It may be OK to wait through the weekend and call to schedule with their normal vet during business hours. They may ask you to send pictures and will want to know whether your dog is scratching or licking the skin.

If your dog is licking or chewing, a comfy collar is recommended until they can be seen by a veterinarian.

Symptoms of Skin Ulcers in Dogs

Symptoms of skin ulcers in dogs include:

Red, oozing sore or sores
Hair loss
Inflammation (swelling) of the skin
Affected area is painful to the touch
Odor
Area may be itchy
Affected area may be found over pressure points (such as joints)
Affected area may have dried crusts on the top or be weeping (leaking fluid)

Causes of Skin Ulcers in Dogs

Ulcers on the skin can be caused by many different things. Any condition that changes blood flow to the skin can result in ulcers forming.

Here are a few conditions that are linked to skin ulcers in dogs:

Hereditary disorders: Rarely, a dog can be born with congenital skin issues that show as ulcerations. Familial dermatomyositis is an example of an inherited skin condition that shows up in young puppies, usually younger than six months.
- It is more prevalent in Collie and Shetland Sheepdog breeds. Zinc-responsive dermatosis is another hereditary condition that may cause skin ulcers. The Siberian Husky and Alaskan Malamute breeds are more likely to be affected by this skin disease, which leads to ulcerated skin on the face.
Self-trauma/pyotraumatic dermatitis: Allergies are very common in dogs and can lead to extreme itchiness of the skin and self-trauma, which can show up as hot spots or ulceration of the skin from a dog licking or chewing themselves.
- These spots are often infected by the bacteria from the skin and mouth of the dog. This is known as acute moist dermatitis, pyotraumatic dermatitis, or a hot spot, and is a very common cause of skin ulceration. Chronic pain, like joint or nerve pain, can also lead to intense licking of an area of the skin and cause ulcers.
Other trauma: Burns and pressure sores can lead to ulceration. Burns can occur with exposure to intense heat (like fireworks, a house fire, or the oven), electricity, extreme cold (frostbite), or chemicals.
- Snake and spider bites can also lead to necrosis (tissue death) and ulceration of the skin. Chronic pressure over thin regions of skin is a common source of microtrauma that leads to skin ulcers in senior dogs that like to lie on hard floors.
Skin infections: There are lots of different things that can cause skin infections. Bacteria, yeast, fungi, and protozoa infections can all lead to skin ulcers. Staphylococcus bacterial pyoderma, candidiasis, blastomycosis, cryptococcosis, neosporosis, and cutaneous leishmaniasis are all examples of skin infections that can lead to ulcers of the skin.
- Dogs can be exposed to these organisms by other dogs, the environment, and even their pet parents.
Vasculitis: Sometimes infectious diseases can disturb blood flow to the skin, like in the tick-borne illness Rocky Mountain Spotted Fever. This can lead to skin rashes and ulceration from poor blood supply. Cutaneous vasculitis is another condition where blood flow is changed by an infection, food, vaccine reaction, or inherited condition.
- In dogs with vasculitis, the blood vessels become swollen, which can lead to ulcers forming on the skin, especially the ear margins.
External parasites: Flies and mange mites can lead to ulceration of the skin. Fly bite dermatitis results from repeated trauma to the skin in outdoor dogs that are overwhelmed with flies biting their ear flaps, face, and paws.
- Mange, like demodex and sarcoptes, is a condition where mites burrow into the skin of dogs, often causing skin lesions.
Immune-mediated disease: Immune-mediated diseases are the result of the body attacking itself. It is poorly understood why some dogs develop immune-mediated diseases while others do not, but vets believe these diseases are largely genetic with a combination of environmental factors that may trigger the immune system.
- Pemphigus vulgaris, bullous pemphigoid, systemic lupus erythematosus, juvenile cellulitis (puppy strangles), and vesicular cutaneous lupus are all examples of immune-mediated diseases that can lead to skin ulceration.
Drug reactions: Rarely, a dog will have a reaction to a medication that can trigger an immune-mediated response. This is the case with erythema multiforme, also known as toxic epidermal necrolysis. In this condition, the body has an unusual reaction to a medication that can result in severe ulceration of the skin.
- While this is very uncommon, several drugs have been implicated, including various beta lactam antibiotics (like penicillin and cephalexin), chloramphenicol, trimethoprim sulfas, levamisole, griseofulvin, and topical flea dips.
Skin cancer: Certain cancers can lead to ulceration of the skin. Squamous cell carcinoma is a type of skin cancer more common on light-colored dogs with lots of exposure to sunlight. It can cause oozing ulcers to develop on affected skin.
- Cutaneous lymphoma can also lead to widespread skin ulcers. Mast cell tumors, sarcomas, and mammary tumors are other types of cancer that can lead to ulceration of the skin over the mass itself.

How Veterinarians Diagnose Skin Ulcers in Dogs

If your dog has skin ulcers, your veterinarian will start by getting a complete history and doing a full physical exam.

They will likely ask you the following questions:

Is your dog itchy? Are you seeing them lick, scratch, or chew on themselves?
How is your dog’s appetite and energy level?
Have they had any exposure to any new medications, food, travel, or other animals?
Is there any history of trauma or injury? Do they spend any time outdoors unsupervised?
Are they on regular parasite prevention?

They may decide to do impression smears of the ulcers using slides to look under the microscope for bacteria.

Your vet may recommend a skin culture, where a swab is sent to an outside laboratory to screen for various fungal or bacterial agents.

Your pup’s urine and blood may be collected for additional testing.

Skin biopsies (removal of some tissue) are often recommended to figure out which of the many underlying causes are more likely.

Treatment of Skin Ulcers in Dogs

Treatment of skin ulcers depends on the underlying cause.

If the skin ulcers are caused by a bacteria or have become infected, antibiotics may be prescribed.

If your dog is itchy, Apoquel® or Cytopoint® may be recommended as well to keep them from irritating the affected area while it heals.

If an autoimmune disease is present, steroids or other immunosuppressive medications are often prescribed. Pain management may be needed if your dog’s skin causes severe discomfort.

If your dog is prescribed a new medication, be sure to follow all directions given by your vet.

Pay close attention to any side effects and watch the wounds to see if they are getting better, worse, or remain the same. Start a picture journal, taking a photo of the ulcerated skin every few days to track your dog’s healing.

Your veterinarian may recommend topical skin products that have antimicrobials or antifungals, like Douxo S3 Pyo® Wipes.

Silver sulfadiazine cream is often recommended for burns, and wound care creams like Silver Honey® can help promote healing in many patients.

Avoid using over-the-counter products on your dog’s ulcers without talking to your veterinarian first. Many of these products can have ingredients that burn or delay healing of ulcerated skin.

While your dog’s skin is healing, be sure they are unable to reach the ulcers. A cone may be necessary if they are licking or chewing the lesions.

Keep the ulcerated skin clean and dry.

Recovery and Management of Skin Ulcers in Dogs

One of the most important parts of recovery for skin ulcers is preventing your dog from further irritating the wound(s) while the healing process is happening.

While it’s true that in the wild, wolves will lick their wounds, their wounds are often packed with mud or dirt and they do not have any other options to clean them.

Your dog has better options. There’s no benefit from a dog licking its wounds. In fact, a dog’s saliva has bacteria that can slow the healing process.

It’s better for your dog if you clean their wounds with an antiseptic and keep them clean and dry.

Talk to your veterinarian about which topical cleansing agents they recommend, as they may want you to use a diluted chlorhexidine solution or saline only.

If they approve, consider using a spray product like Vetericyn® Antimicrobial Wound Care Spray, Silver Honey® Spray Gel, or a medicated Douxo S3 Pyo® wipe daily to keep the ulcerated skin clean.

Recovery times vary depending on the severity of your pup’s ulcers, how much skin is affected, and what the underlying cause is.

Most superficial skin ulcers will heal in 10 to 14 days with proper treatment. Deeper ulcers may take several weeks to heal.

Some patients are helped by other wound therapy options. Some veterinarians may offer cold laser therapy, light therapy, or cold hydrotherapy to promote blood supply and healing to the affected area. Talk to your veterinarian about what is best for your dog’s skin ulcers.