What does dermatitis look like on a dog

By Isabella Storyclaire

last updated September 16, 2024

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Dermatitis in Dogs: What to Know

Dermatitis in dogs is a common diagnosis, but what does it actually mean? Heres what to know about this group of skin conditions, including possible symptoms and treatments.

What Is Dermatitis in Dogs?

Dermatitis refers to a variety of issues that cause inflamed, often itchy, skin in dogs. Unfortunately, the word dermatitis is extremely generic, explains Dr. Domenico Santoro, DVM, Associate Professor of Dermatology at the University of Florida College of Veterinary Medicine. Essentially it just means inflammation of the skin, which is about 90% of what we see in a multitude of diseases.

Signs and Symptoms of Dermatitis in Dogs

Itching, scratching, and excessive licking or biting are common signs of dermatitis in dogs. Dermatitis may occur because of secondary bacterial infections. A skin problem may start as a minor itch, but as the dog scratches, then chews and licks, they open the skin, introducing bacteria. Small, pimple-like bumps erupt, burst open, and lead to crusting and scaling.

If the problem moves from the skins upper layer to deeper layers, the infected area may become painful and leak fluid. Dead skin may even fall off.

When inflammation doesnt go away, the skin becomes thickened and darkens. It may start to become scaly, discharge more fluid, or give off a strong odor. If your dog has dermatitis, you may also see pus-filled blisters, scabs, and hair loss, among other symptoms.

Causes of Different Kinds of Dermatitis in Dogs

Because dermatitis refers to so many different conditions, there are many possible causes, including: irritants that touch the skin, burns, trauma, allergies, such as atopic dermatitis or food sensitivities, and systemic diseases, which are conditions that affect the whole body. Infections can also cause dermatitis, and can be caused by bacteria, viruses, external parasites (like mites or fleas), or fungi (such as yeast).

Ear Mites in Dogs

Ear mites are highly contagious mites (a type of small bug). As their name suggests, ear mites usually show up in dogs ears (especially puppies).

Hot Spots in Dogs

Hot spots, also called pyotraumatic dermatitis, usually result from underlying issues (like flea bites or pyoderma) that encourage a dog to scratch and chew. The scratching creates opportunities for bacteria to enter, while the chewing creates a moist environment where the bacteria thrive, causing the lesion to quickly worsen, hence the name hot.

Malassezia Dermatitis in Dogs

Malassezia yeast is a yeast (a type of fungus) thats already present on dog skin. But when it overproduces, it can irritate your dogs skin and result in canine yeast dermatitis.

Mange in Dogs

Mange is a skin disease caused by mites on your dog. There are two types of mange in dogs: demodectic mange and sarcoptic mange (also known as canine scabies). Demodectic mange, or demodicosis, occurs when Demodex mites, which normally live on your dogs skin, multiply unchecked in hair follicles. In contrast, dogs get sarcoptic mange, a highly contagious condition, when a mite called Sarcoptes scabiei moves from host to host.

Pyoderma in Dogs

A bacterial skin disease, canine pyoderma has several main forms. Often caused by the bacteria Staphylococcus pseudintermedius, skin fold (or surface) pyoderma appears in moist folds of skin or wrinkles. In superficial pyoderma, the infection has penetrated a bit deeper. Deep pyoderma occurs once the infection spreads to the skin layer closest to the dogs muscle.

Seborrheic Dermatitis in Dogs

Seborrhea is a condition where the outer layer of skin is renewed at an abnormally fast rate. Primary seborrhea in dogs is hereditary, while secondary seborrhea results from underlying medical conditions (like allergies or hormonal problems).

Skin Allergies in Dogs

Skin allergies (also known as allergic dermatitis) are the most common type of allergic reaction in dogs. They are often caused by allergies to flea bites, food, or environmental factors (atopic dermatitis).

Walking Dandruff in Dogs

Also known as walking dandruff, cheyletiella mites are contagious and can live off a dog for up to 10 days. Youll spot tiny, white moving specks on your dogs back and trunk.

Diagnosing Dermatitis in Dogs

Your vet will take your dogs medical history, then examine them and analyze their symptoms. This will help inform them about what type of dermatitis your dog may have. In the case of flea allergies, for example, your doctor will be able to see flea bites on your dog.

In many cases, your vet will perform skin scrapings or remove discharge. Once they obtain these samples, the vet will examine them under the microscope to look for yeast, parasites, mites, or other organisms.

If there are underlying causes, your vet will determine what they are. This may involve blood work or other examinations. For example, your vet may conduct an intradermal skin test to identify environmental allergens. To identify food allergies, they may change your dogs diet.

Dog Dermatitis Treatment

Treating dermatitis ultimately depends on the underlying source causing the inflammation of your dogs skin. Additionally, treating the specific symptoms of your dogs skin condition is important to prevent them from causing further trauma to themselves.

To treat itching, your vet may prescribe antihistamines, steroids, or other oral medications. They may also add fatty acids to your dogs diet. Topical anti-itch sprays can help minimize discomfort. A recovery collar can prevent further infection due to chewing and scratching.

If the cause is yeast, your vet will prescribe topical and oral antifungals. Your vet may recommend washing with canine shampoos with benzoyl peroxide, selenium disulfide, or other products designed to remove scale and grease. They may also prescribe an antifungal dog shampoo containing chlorhexidine, miconazole, or ketoconazole.

If the cause is bacteria, your vet may prescribe oral antibiotics. Theyll likely recommend regular cleansing with a mild antiseptic or antimicrobial shampoo, then using an oatmeal-based dog shampoo to soothe irritated skin. Its important to thoroughly dry your dog after bathing them. Dampness creates a breeding ground for bacteria or fungi.

If there are mites or fleas present, your vet will likely recommend topical and oral products designed to kill them. If your dog has a flea allergy, use the veterinarian-recommended flea treatment on your dog, and add a flea and tick preventative to avoid re-infestation.

Mites can be hard to find, so your vet may treat suspected cases the same way they would treat confirmed cases. Your vet will likely recommend oral medications like antibiotics and antihistamines, as well as topical options like miticidal shampoo. You will want to wash all canine bedding repeatedly. Treat the environment with dog-safe insecticidal sprays and be sure to disinfect grooming equipment.

If necessary, your vet may refer your dog to a veterinary dermatologist.

New Medications for Dogs With Dermatitis

In recent years, newer, safer anti-inflammatory treatments for dermatitis in dogs have become available. In terms of therapies, you have the antipruritic anti-itch medications, Dr. Santoro explains. These include lokivetmab, brand name Cytopoint, and oclacitinib, brand name Apoquel.

Lokivetmab fights one type of protein that helps create allergies. Administered by an injection just under the skin, each dose of lokivetmab lasts from four to eight weeks. Oclacitinib is a daily oral medication that reduces itchiness and inflammation due to allergic reactions.

Theres also the new liquid oral formulation of cyclosporine, adds Dr. Santoro. Cyclosporine decreases a dogs immune response, which in turn decreases allergy-related itching and inflammation. Talk to your vet about whether one of these medications could be helpful to your dog.

Types of dermatitis

Each type of dermatitis has different symptoms and tends to occur on a different part of the body. It's possible to have more than one type at a time.

Dermatitis also is called eczema. Symptoms include itchiness, scaly skin, a swollen rash, oozing blisters and dandruff-like scaling. The condition is not passed from person to person.

Learn about the symptoms of common types of dermatitis.

Stasis dermatitis

Common symptoms of stasis dermatitis are:

Thickened, discolored skin on the ankles or shins.
Itching.
Open sores, perhaps with oozing and crusting.
Swelling.

Stasis dermatitis occurs when varicose veins or other circulatory conditions cause fluids to build up in the lower legs. The swelling produces pressure beneath the skin and slows the flow of blood and oxygen to the skin.

Allergic contact dermatitis

Common symptoms of allergic contact dermatitis are:

Itchiness.
Bumps and blisters, sometimes with oozing and crusting.
Swollen rash.

Allergic contact dermatitis results when the skin touches substances that it's sensitive to. These substances are called allergens. The rash usually affects only the area that came into contact with an allergen. Common allergens are perfumes, personal care products, poison ivy, ragweed pollen and nickel, which is used in jewelry and other items.

Atopic dermatitis

Common symptoms of atopic dermatitis are:

Dry, cracked skin.
Itchiness.
Raw skin from scratching.
Small, raised bumps, on brown or Black skin.
Oozing and crusting.
Thickened skin.

Atopic dermatitis also is called eczema. It often occurs in the folds of the elbows, behind the knees and on the front of the neck. It can flare and then clear up for a time.

Irritant contact dermatitis

Common symptoms of irritant contact dermatitis are:

Itchiness.
Bumps and blisters, sometimes with oozing and crusting.
Swollen rash.

Irritant contact dermatitis develops when the skin comes into contact with certain things that cause a rash. Irritant contact dermatitis is different from allergic contact dermatitis but shares some features. Some people react to strong irritants after just one exposure. Others may develop a rash after repeated contact with even mild irritants. Common irritants are solvents, bleach, soap and hair products.

Neurodermatitis

Common symptoms of neurodermatitis are:

An itchy, scaly skin patch or patches.
Thick, leathery skin.
Raised, rough patches that are inflamed or darker than the surrounding skin.

Neurodermatitis also is called lichen simplex chronicus. The more you scratch, the more it itches. It often affects areas that can be reached for scratching the scalp, neck, wrists, forearms, ankles, vulva, scrotum and anus.

Perioral dermatitis

With perioral dermatitis, small pus-filled bumps appear around the mouth. This type of dermatitis also can affect the skin around the nose, cheeks and eyes. The exact cause of perioral dermatitis is unknown, but the corticosteroid medicine contained in some inhalers, nasal sprays and creams may play a role.

Seborrheic dermatitis

Common symptoms of seborrheic (seb-o-REE-ik) dermatitis are:

Dandruff.
Patches of greasy skin covered with flaky white or yellow scales or crust on the scalp, face, sides of the nose, eyebrows, ears, eyelids, chest, armpits or groin area or under the breasts.
Itchy rash.

Seborrheic dermatitis is often found on oily areas of the body. It also can appear on the scalp as stubborn, itchy dandruff. In infants, this type of dermatitis is known as cradle cap.

Dec. 19, 2023

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Kelly AP, et al. Atopic dermatitis and other eczemas. In: Taylor and Kelly's Dermatology for Skin of Color. 2nd ed. McGraw Hill; 2016. https://accessmedicine.mhmedical.com. Accessed May 9, 2022.
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See more In-depth

Dermatitis in Dogs: Causes, Symptoms, and Treatment

What is dog dermatitis?

The term canine dermatitis simply means inflammation (redness and often itchiness) of the skin. This is a general term that may be used to describe skin irritation caused by any disease. There are many causes of skin inflammation in dogs. Some of the more common diseases that lead to dermatitis are atopy, flea allergy dermatitis, and food intolerance or allergy.

Causes of Canine Dermatitis

There are many causes for dermatitis in dogs, but the more common ones are as follows:

1. Canine atopic dermatitis(also called canine atopy or allergic dermatitis)

This is a complicated disease process where affected dogs may be genetically predisposed to developing atopy. It is estimated that roughly 10% of dogs have atopic dermatitis. Dogs with atopic dermatitis have a defect with their skins natural protective barrier. Most of the allergens that cause itching in these dogs enter through contact with their skin and its defective barrier.

Animals with atopic dermatitis have a history of pruritus (i.e. licking, chewing, scratching) that may or may not be accompanied by recurrent skin and/or ear infections. Signs can be seasonalor non-seasonal. They may also start seasonally and then progress to non-seasonal (e.g. year-round).

Dogs with atopic dermatitis often have areas of reddened skin, raised bumps, scratches, crusts, and may have thickened skin from a long history of having dermatitis. The itchy areas in these dogs often include the armpits, lower abdomen, pawsand in-between toes, and the area around the dogs eyes, ears, mouth and lip folds, and bottom.

Most of these dogs start to show signs between 2-6 years of age. As this disease tends to be inherited, multiple breeds are predisposed.

Commonly affected breeds include:
Labrador Retriever
Golden Retriever
Boxer
Cocker Spaniel
Bulldogs
Terriers (most, including Pitbulls)
German Shepherds

However, many dogs including mixed breeds can have atopic dermatitis.

Early skin signsinclude reddened circular areas, patches, and small bumps. Self-trauma from licking, chewing and scratching can lead to signs of fur loss, wounds, thickened and darker colored areas of skin.

Treatment / Management of Atopic Dermatitis:

Identification and avoidance of the allergen and infection with bacteria or yeast (often considered secondary bacterial dermatitis or yeast dermatitis)
Improvement in skin and coat hygiene and care (e.g. bathing)
Reduction of itching and skin wounds with medications (e.g. topical and/or systemic)
Targeted therapy of the allergy with intradermal allergy testing and desensitization

Canine atopic dermatitis is a life-long condition that can severely affect both patient and pet owner quality of life. Preventing or minimizing the frequency of skin flare-ups improves patient quality of life and owner satisfaction, as well as lessens adverse effects from prolonged administration of systemic medications. Flare-ups can be lessened by identifying and desensitizing the animal to offending environmental allergens when your veterinary dermatologist performs an intradermal skin test and then formulates an injectable to desensitize your dog to their allergens over time. This immune modification may take upwards of a year to determine its full benefit.

2. Flea Allergy Dermatitis (flea bite hypersensitivity)

Dogs with flea allergies have an allergy to a protein in flea saliva.

Skin issues in dogs with flea allergy dermatitis often appear as small raised bumps and crusts seen over the lower back, above the tail, and inner thigh area. These dogs may scratch their sides, thighs, belly, lower back, neck, and ears. Often these dogs are quite restless and are almost constantly scratching, chewing, and/or licking at their skin. Dogs with long-term flea exposure can have thickened skin that may become a dark grey color and the fur loss may cover most of their body.

The most common signs of flea allergy dermatitis are fur loss and the presence of fleas along with marked itchiness. This type of dermatitis is diagnosed by the skin changes seen and ruling out other possible causes for the skin issues. Signs of itchiness may develop minutes to days after the flea bites, depending upon if the dog has a more immediate or delayed immune reaction to the flea saliva.

Flea allergy dermatitis does not usually occur before 1 year of age. Any breed of dog can be affected. Dogs with severe flea allergies are often found to be nearly flea-free due to excessive self-grooming as they are so itchy.

To treat and prevent flea allergy dermatitis, appropriate flea treatment and prevention of flea infestations is a must. Also, proper treatment of any secondary skin infection, resulting in bacterial dermatitis or Malassezia dermatitis, must occur to resolve the dogs itching.

3. Food Allergy Dermatitis

Dogs who have food allergies typically develop a hypersensitivity reaction to either a protein or carbohydrate in the food or treats that they eat.

The most common sign in food-allergic dogs is itchiness/scratching which may be focused on one or multiple areas of the dogs body. The more common areas where dogs with food allergies lick, chew or scratch, are their ears, feet, underneath their chest or abdomen, and less often around their hind-end.

Although we wont discuss this further here, food-allergic dogs may also show GI signs such as vomiting, diarrhea, a marked increase in stools/feces produced, soft to loose stools, straining to pass stool, gassiness, and possible weight loss. These signs are usually noticed year-round unless the food or treat causing the issue is not constantly fed.

Although dogs with food allergies typically develop clinical signs of disease in young adulthood (14 years old), the age of onset in dogs has been reported to range from <6 months to 13 years. Thus, a food allergy may be a particularly likely cause for dermatitis in dogs when first seen at either a very young or very advanced age.

Breeds that more often have food allergy issues are:

German Shepherds
Labrador Retrievers
French Bulldogs
West Highland White Terriers

This does not mean that other dog breeds cannot have food allergies.

For dogs presenting to a vet for dermatitis or itchiness, food allergies may be determined to be the cause for up to 24-40% of cases.

The only reliable way to diagnose food allergies is by performing an elimination diet trial. There are a couple of tests that may help when selecting which foods to avoid when choosing a diet. However, these tests (western blot blood test and skin/patch testing) cannot diagnose a food allergy. The most common sources of food allergies in dogs are beef, dairy products, chicken, wheat, and lamb.

For more information on performing a diet trial please see: How to Perform a Food Trial for Your Pet's Allergies

Other Diseases That May Causes Changes to Your Dogs Skin

Clinical Signs of Dermatitis in Dogs

Dermatitis in dogs can be seen as any combination of the following symptoms:

Abnormal redness of the skin
Thickening of the skin
Itching
Scaling
Dark color (grey/black)
Fur loss (alopecia)
Unusual odor
Excessive oil production of the skin

How will the vet test my dog for dermatitis?

Initially, your dogs vet may recommend any combination of the following tests to help determine the cause of your dogs skin issues:

Medication Trial (antihistamine, Cytopoint, Apoquel or Corticosteroid (steroid))
Diet Trial (offering a food containing protein and carbohydrate source that your dog has not had before)
Skin Scrape (checking for mites)
Skin Biopsy
Intradermal Skin Testing
Bloodworkto check for specific allergies, hypothyroidism, or Cushings Disease

Veterinary Treatment Options for Canine Dermatitis

The treatment that your vet recommends will depend upon your dogs diagnosis - either general such as seasonal or environmental allergies, or specific (i.e. flea allergy dermatitis or allergy to soy).

Some of the treatment options that your vet may recommend are as follows:

Medicated baths with a shampoo made specifically for dogs with dermatitis
Flea Prevention/Control
Supplements
Cytopoint
Apoquel
Hypoallergenic diets
Antihistamines
Antibiotics and Antifungals (to treat secondary skin infections if found)
Immunotherapy(when exact allergens causing the issue have been identified)
Corticosteroids

What about giving my dog over-the-counter medication for their itchy or red skin?

Do not give over-the-counter (OTC) medications to your dog without talking to your vet first. If not given appropriately or in the right case, OTC medications can be dangerous.

Home Treatment for Dermatitis in Dogs

There are several things you can do at home to keep your dog as comfortable as possible while waiting for your vet appointment and allergy consult. A few safe treatments include:

If your dog is licking or chewing excessively at themselves, an Elizabethan collar (cone) may be helpful to lessen further damage to their skin.
If your dog is itchy everywhere, you may bathe your dog with a mild shampoo (i.e. oatmeal-based) daily to every other day. Make sure to use lukewarm water and thoroughly rinse the shampoo away.
Any individual wounds may be cleaned with a mild soap or dilute betadine solution twice daily and then blotted dry.

Can dog dermatitis be prevented?

It all depends upon the underlying cause of your dogs itchy, red skin. As dermatitis is often due to an underlying allergy to something in your pets environment, flea saliva protein, or food allergy, avoiding the triggers can help, but this is not always possible.

By keeping in close contact with your dogs vet and following their recommendations you will likely be able to minimize the frequency and severity of your dogs skin flare-ups. With seasonal or environmental allergies in dogs, much as for people with seasonal allergies, there is no cure. The goal is to keep dogs as comfortable as possible and avoid secondary skin infections as much as we can.

My dogs skin isnt getting better. When should I schedule a vet visit?

If your dog is experiencing any of the following symptoms, its time to schedule a vet visit:

Scratching more than usual and seems uncomfortable.
Licking, chewing, or scratching to a point where they are developing sores.
Fur loss
Head shaking
Scratching at ears
Lethargy
Lack of appetite

Hot Spots (Moist Dermatitis) in Dogs

Common Myths About Allergies in Dogs

Common Skin Diseases in Dogs

Need to speak with a veterinarian regarding your dogs dermatitis or another condition?

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