This article was updated on October 15th, 2023
One common problem that we often encounter as veterinarians is the presence of scabs (serous crusts) on a dog’s skin. Scabs form over irritated and compromised skin and serve as protection from bacteria and infection, like a band-aid. They can be the result of:
- trauma (an injury)
- self-trauma (for example, a dog scratching excessively and injuring their skin)
- a health issue, such as a skin infection or an allergy.
In this article, we will review the top causes (with pictures) and discuss how to help your dog.
5 Common Causes of Scabs on Dogs (With Pictures)
A wound is any injury that causes damage to the dog’s skin and often the underlying tissues. The time it takes for a scab to heal is about one to two weeks (depending on the size and severity of the injury). If your dog’s scabs are due to an injury, view our article about Wound Healing in Dogs.
Allergies in dogs are very common: I see an average of 10 dogs a week with allergies in my veterinary practice. Dogs can develop allergies to a wide range of things, including pollen, mold, dust mites, fleas, and certain foods. Allergies can cause the skin to become red, flaky, thickened, and itchy.
Dogs with allergy issues often exhibit excessive itching, scratching, and paw chewing due to skin irritation. Excessive scratching and irritation can lead to hair loss and scabs, as shown on the pictures below.
To treat allergy-related issues, the underlying allergy must be controlled. This can be accomplished in many ways, for example with allergy prevention medications, shampoos, wipes, and diet or environment changes. If a secondary skin infection is present, appropriate medication will be needed to treat the infection.
Learn more: Skin Allergies and Scabs
3. Skin infections
Scabs form to serve as protection from bacteria and infection, like a band-aid. The most common types of skin infections include:
Bacterial Infections: Bacterial infections often cause redness, whiteheads (pustules), flakes and scabs, as shown in the pictures below. You may also notice your dog itching, chewing, or excessively licking. Staphylococcus pseudintermedius is the most common bacteria causing skin infections.
With bacterial infections, there is usually inflammation of the hair follicle called folliculitis. This can lead to the build-up of crusts (scabs form). There may be small bumps (papules), raised hairs (tufted papules) and hair loss. Learn more about Folliculitis.
Yeast Infections: Dogs can develop skin yeast infections, which are characterized by a distinctive sour or musty odor. This is often referred to as smelling like corn chips! These infections may be found anywhere on the body but are especially prevalent in areas of high moisture and little light (ears, skin folds, between the digits, groin, underarms).
Yeast infections are treated with oral antifungals, shampoos, powders and creams. As with bacterial infections, the underlying cause will need to be found and treated. Learn more about Yeast Infections.
“Hot Spots” infections: As the name suggests, hot spots are specific isolated inflamed and moist areas of your dog’s skin. Hot spots form most commonly due to scratching and self-trauma resulting from bacterial infections, insect bites, or allergies.
Hot spots are treated with both oral and topical medications which will be chosen depending on the underlying cause. Learn more about Hot Spots.
Ringworm infections: Despite being named after a worm, ringworm is actually caused by a fungus. It infects the skin in circular lesions resulting in scabs, soreness and hair loss. It is an infection that can spread quickly and even pass to humans. Learn more about Ringworm.
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4. Parasites (mites, fleas, etc)
Mites (Mange): Mites are microscopic parasites (under 1mm in length) that can affect your dog’s skin and cause intense itching, discomfort, crusty and scaly skin, and hair loss.
There are two main types of mange in dogs: demodectic and sarcoptic:
Demodectic Mange primarily affects young, old, pregnant, and immunocompromised dogs (e.g., chemotherapy, corticosteroids, oclacitinib- Apoquel®). It is not always itchy. These dogs lose hair, typically beginning around the eyes, but should not scratch or form scabs. Learn more about Mites.
Skin issues from demodectic mange.
Pictures: © Ian Brett Spiegel VMD, MHS, DACVD
Sarcoptic mange (scabies) is a mite infestation that is contagious and acquired through contact with the mites in the environment or from another host (e.g., fox, coyote, wolf, other dog). These infestations are very itchy, and excessive scabbing of the skin is common. The most common areas affected are the ear flaps (margin), elbows and hocks (ankles).
Learn more about Scabies.
Fleas, Ticks, and Lice: Fleas are hard to spot, but their droppings (flea excrement) can usually be spotted in a dog’s coat. Dogs infected with fleas, ticks, or lice will typically excessively lick, scratch, or even have scabs or hot spots. Some dogs experience an allergic reaction to flea saliva, which can cause inflammation, redness, and scabbing, often in the area near the base of their tail.
Learn more about Flea Scabs or Tick Scabs.
Both fleas and ticks can transmit disease to humans, so it is essential to keep them off your dog. The best treatment for these parasites is prevention and there are several medications that will protect your dog. Ask your veterinarian which is right for your pet.
5. Flaky skin
Often, flaky skin is nothing to worry about. Just like humans, dogs can get flaky skin. Giving your dog fatty acid supplements or using moisturizing shampoo may help.
However, flaky skin can also be an indication of something more serious going on with your dog, including allergies, hypothyroidism, autoimmune disorders, and other skin conditions. If flaky skin persists, makes your dog uncomfortable, or if you observe other symptoms such as hair loss, consult your veterinarian.
Other Potential Causes of Scabs
There are numerous other issues that may cause scabs on the skin of a dog. These include autoimmune disorders, hormone imbalances, and nutritional issues. If your dog is forming scabs without trauma (injury), they should be evaluated by their veterinarian as soon as possible.
Is There Medicine I Can Put on a Scab to Help My Dog?
In general, scabs from injuries should be left alone to heal: scabs are marvelous wound protectors and do not need additional medications to do their job.
However, multiple scabs over an area of skin can be an indication of an underlying skin problem (as opposed to an injury). In these cases, your veterinarian may prescribe a topical or systemic antibiotic. The medication will address the underlying condition.
When to Worry
A veterinarian should have a look at your dog to identify if there are:
- Significant changes in your dog’s skin
- Sudden appearance of sinister-looking lesions (scabs on dogs should be monitored to make sure they don’t evolve into something more serious)
- Areas causing your dog a lot of discomfort or resulting in excessive scratching or licking
It’s also important to pay attention to your dog’s overall well-being. If your dog is acting differently from his usual or seems unwell, you should take your dog to the veterinarian.
Scabs by Location (Ears, Nose, Head, Neck or Nipples)
The location may tell you a bit more about what your dog may be suffering from. You may be interested in the following articles about most common scabs in dogs, by location:
Frequently Asked Questions
What other symptoms might appear alongside crusty scabs?
The first clue you’ll see if your dog develops scabs is itching: scratching, licking an area, or rubbing himself against the floor or other objects. The skin might also be red, moist, or has a foul smell.
Where do scabs on dogs appear most frequently?
Scabs appear anywhere on the skin where there has been a trauma that breaks the skin barrier. These injuries can range from superficial to severe. Because scabs can be the result of self-inflicting trauma (excoriations), the most common areas to find scabs are those that the dog can reach with their claws or paws. These scabs result from self-trauma (scratching and licking) and typically have an underlying cause such as an infection or allergy. The back, chest, and under the ears are common areas for scabs. Injuries such as cuts and scrapes can be found anywhere.
Top causes of scabs due to injuries
1. Cuts and scrapes: Like humans, dogs can sustain injuries to their skin, such as cuts and scrapes, resulting in a scab. If the injury is superficial and not infected, most of these will heal on their own. More significant cuts may need to be stitched, and any injury that gets infected will need to be seen by a veterinarian.
2. Self-trauma: The second most common reason for scabs in dogs is self-trauma. These scabs form after a dog has scratched or licked itself aggressively. If your pet is experiencing these issues, the underlying cause needs to be treated. Some issues that may cause a dog to scratch excessively include:
- environmental allergies
- food allergies
- skin infections
- ear infections
- parasites (fleas, ticks, mites, etc)
Understanding each of these potential reasons can help you find the proper treatment.
Read More About Dog Skin Problems:
- All skin problems and conditions
- Lumps and bumps (and red lumps and bumps)
- Tumors, Warts, or Cysts
- Scabs or blood blisters
- Skin lesions or skin infections
- Cancerous lesions or lumps
- Skin allergies and rashes, heat rashes, hot spots
What Are Scabs?
These bumpy and dry protective formations (crusts) develop over a sore during the healing process. The scab starts to form as soon as the skin is injured. Cells found in the blood known as platelets, gather at the break in the skin and clump together. This clump is the foundation of a blood clot. This will aid in halting the bleeding. When the clot dries, it becomes a scab. Platelets then work to form a more permanent clot while the injury heals.
In other words, when exposed to air, platelets break apart and form thread-like structures. These threads form a web-like mesh that traps any red blood cells from escaping the wound. A scab forms when this mix of the mesh and red blood cells dries.
Scabs are typically reddish-brown in color and may be found anywhere on the skin. The size of the scab will vary and will correlate to the size of the injury.
Scabs are usually dry and rough on the surface, and moist below the surface. Scabs form to serve as protection from bacteria and infection, like a band-aid.
Disclaimer: This website's content is not a substitute for veterinary care. Always consult with your veterinarian for healthcare decisions. Read More.