Crusty Scabs Around Your Dog’s Mouth? (6+ Likely Causes!)

As you play catch with your loyal dog who just won’t leave your side, you see something disturbing that catches your eye.

“Why are there crusty scabs around my dog’s mouth?”, you wonder in panic.

Crusty scabs can be an indication of an abnormal diet, irregular hormone regulation, allergies, skin infections, or acne in dogs.

A relatively common problem also associated with crusty scabs is lip fold dermatitis. This condition is prevalent amongst dogs with folds of skin, such as the English bulldog or Shar-Pei.

In many cases, crusty scabs around the mouth tend to develop when a dog constantly irritates the affected area on the mouth by scratching, licking or biting.

Treatment for crusty scabs typically calls for topical ointments, although it is important to consult with your vet first before applying anything on your dog.

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Why Is My Dog’s Mouth Crusty? Why Does My Dog Have Sores Around Her Mouth?

Dogs may develop crusty mouths and sores due to problems such as dehydration, vitamin deficiencies, or hormonal imbalances.

These conditions prevent the formation of new, healthy layers of skin to replace the dry, crusty layers. Additionally, damaged skin makes it easier for infections to develop and for sores to form.

Sores and skin disease around your dog’s mouth can also be caused by canine acne, infections and allergic reactions. The resulting physical irritation from scratching and biting affected areas then creates a crusty appearance.

1. Dehydration

Water is one of the most important nutrients when it comes to pet health in general. It is particularly vital for the development of healthy cells, as it is involved in all processes of cell renewal.

Low body water percentage can cause the skin to become tight, dry, and crusty. Poor skin conditions allow infections an opportunity to settle in, creating sores around the mouth.

Signs of dehydration such as dry and crumbly poop will be more prevalent in drier seasons such as during summer or winter. Therefore, always make sure to have plenty of clean, fresh water on hand for your pup!

2. Nutrient Deficiencies

Nutrient Deficiencies

While all nutrients are important in maintaining a healthy dog, some of the more important ones that boost oral skin health include vitamin B, iron and zinc.

Vitamin B, notably vitamin B12 and vitamin B2, are required to maintain healthy oral structures. Vitamin B12 promotes cell production, reduces acne and prevents dry skin. Vitamin B2 promotes cell turnover and protects skin integrity through collagen maintenance.

Absence of vitamin B can lead to a cracked and crusty mouth, inflamed tongue and oral cavity- as well as anemia in serious cases.

Iron provides benefits similar to vitamin B, such as increasing cell formation and collagen maintenance. Iron deficiency can result in similar effects to vitamin B deficiency as well, such as pale, dry skin and anemia.

Zinc is important in managing healthy skin as it regulates the production of new cells. Zinc deficiency can lead to formation of pus-filled scabs on the mouth, skin redness and loss of hair.

Deficiencies in these nutrients weakens the skin barrier, heightening the risk of infections and making it easier for sores to form.

3. Hormonal Imbalances

Hormonal imbalance is generally caused by hereditary conditions, and is often linked with skin abnormalities such as crusty scabs and skin irritation.

Examples of hormone irregularities include hypothyroidism and Cushing’s disease. In some cases, tumors can lead to changes in hormone regulation.

Treatment of hormonal imbalances can involve surgery to remove any relevant tumors, radiotherapy to reduce the activity of overactive organs, or medications given orally or through injections.

Generally, lifelong treatment is required for hormonal imbalances and your dog will need to be regularly examined by your vet to observe for side effects and relapse.

4. Canine Acne

Canine acne has the appearance of pimples or sores around a dog’s mouth. In severe cases of acne, your dog may have swollen lips, crusty scabs and bloody wounds.

The potential causes of acne include genetic predispositions, and trauma to facial structures that become inflamed. Without treatment, canine acne can lead to infections and long-term scarring.

5. Infections


Bacterial infections such as superficial bacterial folliculitis can irritate the skin and create sores and scabs. Folliculitis typically develops as a secondary infection to other skin issues, such as mange, fleas, allergies and wounds.

Bacterial infections develop when a dog irritates an affected area by biting, chewing or scratching. This opens up a wound or makes it larger, which allows bacteria to seep in and create pus-filled sores.

If your dog continually damages the affected skin, crusty scabs will begin to form.

Fungal infections, particularly ringworm or dermatophytosis, can lead to sores,scabs, and hair loss. Victims of ringworm develop round patches of irritated skin that can spread amongst both humans and animals.

A puppy is more susceptible to ringworm infections and can initially catch the parasite from contact with fungus-infected soil.

Parasitic infections involving ticks, mites and fleas can create sores and scabs around your dog’s body. More crusty scabs can form if your dog scratches the inflamed and itchy skin.

Red patches of skin, crusty scabs, hair loss, excessive scratching, and chewing of the skin are among the most common symptoms of parasitic infestations.

6. Allergies

Allergic reactions such as canine atopic dermatitis can initially cause sores to develop around the mouth, which can then become scabs after your dog scratches at it.

Canine atopic dermatitis is a hereditary condition where the skin becomes inflamed due to an allergic reaction. Causes of the allergic reaction are typically airborne substances such as dust or pollen.

In some cases, skin irritation can develop from coming into contact with objects such as lawn chemicals, shampoos, and other cleaning products.

Houseplants such as the Dieffenbachia or Dumb Canes can lead to sores if they are chewed on. The oxalic acid and calcium oxalate present in the plant can cause an allergic reaction by irritating the mucus membrane.

Other signs of dieffenbachia plant chewing include GI issues such as diarrhea and vomiting. It can be fatal if it is not resolved immediately.

Some other less common medical conditions which can result in sores include:

  • Oral papilloma virus: Also known as dog herpes, it appears as small tumors which usually develops in dogs with immature immune systems
  • Benign or cancerous tumor
  • Alabama rot: A disease that causes blood clotting and kidney damage which can be fatal
  • Pemphigus disease: A rare autoimmune condition where the immune system attacks areas where skin cells connect. Other common symptoms include fever, depression, anorexia, itchiness and pain.

In most cases, crusty scabs develop after your dog physically irritates any sores or affected skin around their mouth.

What Is Lip Fold Dermatitis In Dogs?

What Is Lip Fold Dermatitis In Dogs?

Lip fold dermatitis describes an inflammation of the skin around the lip folds that can develop into sores and crust around the mouth.

The condition is commonly seen in dogs with drooping skin folds such as bulldogs, bloodhounds and springer spaniels.

The folded layers accumulate saliva, heat and food pieces, providing the ideal environment for growth of yeast and bacteria.

Lip fold dermatitis usually progresses from a small irritation on the lips, such as chafing, to inflammation and infection.

Initial symptoms of lip fold dermatitis include:

  • Wet, red lip folds which can be painful and swollen
  • Foul smell
  • Lip scratching

As the condition progresses, other symptoms of lip fold dermatitis may develop, such as:

  • Hair loss
  • Ulcer or sore development
  • Scabs
  • Discoloration of surrounding fur
  • Behavior indicating pain

For temporary relief of dermatitis, you can use products such as Bactine or Apoquel. However, for permanent treatment of lip fold dermatitis it would involve:

  • Removing the surrounding hair
  • Keeping the area dry
  • Regularly cleaning lip folds using a skin cleanser or benzoyl peroxide
  • Rubbing on prescribed rash cream

Severe cases of lip fold dermatitis will require lip fold surgery to completely remove the affected area. Following surgery, your dog will require constant supervision for around one month to prevent excessive chewing and rough play.

How Do I Treaty Crusty Scabs On My Dog?

How Do I Treaty Crusty Scabs On My Dog?

To treat crusty scabs, the most effective method involves identifying the cause first. Your vet will be the best to examine your dog’s medical history and identify any medication or other stimuli causing the crusty scabs.

Examination methods may include bacterial and fungal cultures, allergy testing and skin biopsies.

Some treatment methods targeting crusty skin include the use of topical ointments like coconut oil and aloe vera. These often help soften the skin and reduce inflammation.

Although solutions such as Vaseline, Aquaphor and Penaten cream can help with skin recovery, it can lead to vomiting and diarrhea if your dog ingests too much from licking.

Treating crusty scabs can take longer than expected, especially if your dog continuously irritates the affected region. Using E-collars can be helpful in preventing repeated injury.

It is recommended to ask for advice from your vet first before applying any products on your dog.

Non-Medicated Approach To Treat Crusty Scabs

Generic methods specifically for targeting crusty skin and scab include using vitamin E oil, applying cold or warm compresses, and opting for a healthier diet.

Vitamin E Oil

Vitamin E oil supports the immune system through its anti-inflammatory and antioxidant properties. It also helps to regenerate new cells.

Apply Vitamin E oil on the crusty area around two or three times a day. The oil will soften the crusty scabs, which will then fall off over time when it is replaced by a new layer.

Cold Or Warm Compress

Cold compresses reduce swelling of sores by slowing inflammation and reducing itchiness. This will help to stop your dog from scratching the crusty skin.

Warm compresses promote blood flow to the crusty skin which helps regenerate the skin by delivering nutrients for cell renewal. Warm compress may also stop the skin from being too dry.

Using a wet cloth for compression can provide effective temporary relief for the itchiness caused by crusty scabs, but it will require other treatment methods to ensure the affected skin is renewed.


To promote formation of new skin layers to replace the crusty scabs, a dog will need a well-balanced diet with nutrients such as:

  • Zinc
  • Vitamin A
  • Selenium
  • Omega 3
  • B-Complex supplements with methyl carbylamine B12 and no-flush niacin

Again, water is also a vital factor. Providing your dog with sufficient water and feeding it a healthy diet will go a long way in preventing parasites or infections that may otherwise occur due to weakened immune systems and poor skin health.

Medicated Approach To Treat Crusty Scabs

First aid anti bacterial cream  ointment. Isolated on yellow background.

Medicated solutions to treating crusty scabs aim to either:

  • Retain water within the skin,
  • Remove fungus, bacteria or parasites, or
  • Reduce the inflammation caused by acne or allergies.

The products mentioned below are not a comprehensive list of all medical treatment methods available for crusty scabs. However, it will give you an idea of what to expect.

While many of these products should be safe to use on your dog, always consult with a vet first before applying anything on the affected area.

Water-Retention Products

Ointments such as E45 and Sudocrem help hydrate the skin by forming a protective layer over the dry skin while retaining moisture.

The active ingredients of E45 are liquid paraffin, white soft paraffin and lanolin. These have occlusive and emollient benefits. Occlusives help to create a barrier around the skin to stop water loss, while emollients soften and moisturize the skin.

Sudocrem also contains lanolin, which moisturizes the skin as well. It also contains zinc which regulates cell renewal. Additionally, the benzyl alcohol present in Sudocrem has anaesthetic properties, which reduces or prevents irritation caused by conditions such as acne.

Antifungal, Antibacterial And Antiparasitic Products

Products targeting fungus, bacteria and parasites tend to require longer periods of time before the dog is completely free of its skin problems. Treatment typically uses a combination of oral medication and topical ointments.

Antifungal products tend to use imidazole class drugs such as Fluconazole, Itraconazole and Ketoconazole. These either stop fungal reproduction or growth, and can be given orally or administered via antifungal shampoos.

Alternatives can include items such as wrinkle/skin balm or salve which prevent development of fungus generally with plant extracts.

Antibacterial or antibiotic treatments of the skin often require topical therapy and frequent bathing.

Products tend to include a broad spectrum antibiotic called amoxicillin-clavulanate or cefazolin/cephalexin. These break down bacterial walls and render them vulnerable to be destroyed by the immune system.

Bathing your dog with antibacterial soap such as hibiclens, hibitane or chlorhexidine scrub will also help with destroying skin bacteria.

Antiparasitic treatments can include regular cleaning, implementing collars, manually removing the parasites, or removal of hair.

Seresto Flea and Tick Collar for Dogs, 8-Month Flea and Tick Collar for Large Dogs Over 18 Pounds

Medication will be different for different parasites, and it will be best to ask for help from your vet. They may prescribe medication and recommend sprays, powders or dips.

Topical flea and tick treatments may include active ingredients such as Fipronil and Imidacloprid. S-Methoprene is also an ingredient often combined with Fipronil as it stops growth of parasites.

Examples of popular flea and tick treatments are Frontline and Seresto. In cases where Frontline doesn’t work, there are other methods of parasite prevention that you can learn about through our article here!

Treatment methods for mites and mange can be found by clicking on our article here.

Anti-Inflammatory Products

Pile of Benadryl dropped onto table

Steroids such as hydrocortisone cream reduce and prevent inflammation and swelling by stopping the chemicals that cause the irritated skin to become itchy, swollen and painful.

Benadryl is an antihistamine which helps to reduce allergy symptoms such as rashes and itchiness. A typical dosage of Benadryl is 1-2 mg per pound of bodyweight within a 24 hour period.

It is important to only provide the regular Benadryl in the form of tablets. The syrup version of Benadryl is toxic to dogs due to its alcohol content.

Benzoyl peroxide is an anti-inflammatory, antiseptic and oxidizing topical ointment which can help to treat canine acne.

It works by flushing out hair follicles to remove bacteria, and may be applied alongside topical steroids such as betamethasone or oral steroids such as prednisone.

In Summary

The crusty scabs around your dog’s mouth can be caused by several factors, including dietary issues, abnormal hormone levels, infections, acne and allergies.

Another common cause of crusty scabs is physical irritation, as your dog may scratch and lick the affected skin that is experiencing discomfort.

There are several approaches to treating crusty skin, such as changing to a healthier diet and utilizing topical ointments.

The crusty scabs should heal over time with the appropriate treatment once the exact cause is established. However, it is always recommended to consult with a vet before proceeding with any treatment method to ensure that it will be effective.

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