Black Scabs on Dog: Top Reasons & What to Do

This article was updated on May 2nd, 2023

No owner wants to find black scabs on their dog; for one, they’re ugly and feel unpleasant, but they could also indicate something more sinister going on. Black scabs on dogs come in a range of different shapes and sizes. As a vet, I see black scabs of one form or another most days in the clinic. 

Most black scabs will be insignificant, posing no threat to your dog. However, some black scabs could be linked to a more serious underlying cause and so it’s important to know the difference as an owner.

What does it mean if a scab is black?

Black scabs are similar to other scabs in that they are dry crusty lesions affecting the skin that often develops following a wound or inflammatory process in your dog’s skin. However, the difference is that black scabs are also hyperpigmented – giving them their darker appearance. While this darker appearance can just indicate that the scab is older, hyperpigmentation of the skin usually occurs when excess melanin accumulates in the skin, resulting in a darkening of the skin surface. This process can occur spontaneously or following inflammation of the area affected.

Types of black scabs on dog’s skin

Here is a list of the most common causes of black scabs in dogs:

1. Wounds

One of the most common reasons for a black scab forming on your dog’s skin is following a wound. When your dog gets a scrape or a cut, blood leaks from the area and forms a clot. This is composed of platelets and red blood cells and prevents further bleeding from occurring. As time goes by and the wound heals, the clot dries out and forms a scab. This provides a protective layer over the vulnerable wound underneath while it heals. The scab will often darken as it gets older and the blood dries up, sometimes to the point where it appears black.

Most wounds will heal on their own if left un-aggravated; if your dog has a tendency to lick at wounds then they might require an Elizabethan collar. Larger wounds may require stitches or staples so be sure to seek veterinary advice if this is the case.

2. Allergies

Dogs can suffer from allergies in a similar way to humans. An allergic reaction to something in your dog’s environment or their food will often result in inflammation of your dog’s skin. This appears as redness, a rash or hives on the surface of your dog’s skin and can be very irritating for them.

While an acute allergic reaction may cause redness of the skin, more chronic allergies can result in a darkening of the skin, sometimes to the point where the skin appears black. This is because, over a longer period of time, inflamed skin can become hyperpigmented. As this skin sheds off it can appear as black scabs. 

If your dog has been suffering from allergies for a prolonged period of time then it may be best to get your veterinarian involved. Acute allergic reactions may require steroids or other anti-allergy medication. Food allergy trials or blood tests may also be required to identify the underlying allergen.

3. Parasites (or itching excessively due to parasites)

Parasites like fleas or mites living on your dog’s skin can cause black scabs to appear. Fleas don’t spend long on your dog, they bite and jump off, but they will leave feces on your dog. Flea feces will look like small bits of black dirt on your dog’s fur that can look like black scabs. 

Mites can also affect your dog’s skin; they often bury themselves under the surface of your dog’s skin or affect the hair follicles. This results in inflammation and extreme irritation – dogs with a mite infestation will often frantically itch at themselves to the point of causing self-trauma. The wounds that your dog causes while doing this will form into scabs, which often become darker in color as time goes on. 

It’s very important to keep your dog’s anti-parasite medication up to date to prevent such parasites from taking up residence on your dog. If you think that your dog may have an active parasite infestation then seek veterinary advice. 

4. Growths

Some growths on your dog’s skin can appear like black scabs. Lumps, warts, and masses can grow anywhere on your dog’s body and sometimes these will contain hyperpigmented tissue giving them the appearance of a black scab. It’s also possible that your dog is itching at a mass and causing trauma, which then forms into a black scab as it heals. 

While many skin growths are benign, not all of them are. A certain type of skin mass called melanoma, which contains a lot of the black pigment melanin, often appears very black by definition. These are malignant, or cancerous, lesions of the skin and so should be investigated by your veterinarian immediately. Any masses on your dog’s body that are growing rapidly, changing shape or texture or that appear very black should be checked out by your vet. 

5. Hyperpigmentation

Another reason for what looks like black scabs on your dog’s skin is simply hyperpigmentation (Black spots on dog skin). Pigment is naturally found within your dog’s skin to differing degrees in different parts of their body. Sometimes an area can become very dense in pigment, or become hyperpigmented, this can often appear as black scabs. 

Hyperpigmentation can have many causes including genetics, hormonal imbalances, allergies and skin infections. Usually it isn’t too much to worry about as long as your dog isn’t showing any other symptoms of benign unwell. If you’re concerned then get your vet to check. 

Can I just monitor my dog and wait if my dog has black scabs?

There may be some situations where it’s fine to just monitor and leave a black scab on your dog, however not always and therefore it’s important to know the difference. 

Black scabs that have recently appeared, and that have a known cause such as a recent wound or allergic reaction may be okay to monitor. Often these black scabs will resolve on their own. 

However, black scabs that have been present for a while or that are getting worse should be investigated. Especially if these scabs are associated with a lump or raised area as this could indicate a malignant tumor. 

If you’re worried for any reason then it’s best to have your vet check over your dog.

3 steps you can take at home to help with black scabs

Often when it comes to scabs of any kind, less is more. Scabs are the body’s natural way of healing and so the less interfering the better. If your dog is prone to licking or chewing at wounds then they might need an Elizabethan collar such as this one. There are a few steps owners can take at home to help black scabs heal faster:

1. Gently bathe the scab with warm water, don’t rub the scab too hard as you don’t want it to peel off. I’d avoid any harsh chemical soaps as this can delay the healing process. 
2. Apply cream to the scabbed area, a vitamin E cream such as this will provide vital nutrients to allow the skin to heal. 
3. Once the cream has soaked in, apply vaseline to the area. This will provide a protective barrier over the affected area, preventing bacteria from getting in and keeping the area moisturized.

However, the above steps are no substitute for veterinary care so if your dog’s black scabs aren’t healing, see the vet immediately. . 

Time for scabs to heal

This partly depends on the underlying cause as if this hasn’t been resolved then scabs may keep forming. However, if healing in a healthy manner, most scabs will start to dry up and heal over a course of a few weeks. Sometimes even quicker if the scab is very small. 

Signs that your dog should see a veterinarian

Scabs that keep recurring or that are becoming worse will require veterinary treatment. Black raised scabs or lumps should be investigated sooner rather than later for fear that they could be something sinister. Similarly if your dog is really bothered by the scab and keeps scratching at it then they will likely need treatment to help speed up the healing process. 

If your dog is displaying any other symptoms of being unwell such as vomiting, diarrhea or general lethargy then they should also be seen. 

How can a vet help with black scabs?

Vet Diagnosis
In order to reach an accurate diagnosis, there are various tests that your vet might want to perform. The first thing they’ll need however is an accurate history of exactly what the issue is, when it started and how long it’s been going on for. Therefore, it’s important to have an idea in your head of the answers to these questions (see the next section). 

Your vet will also perform a clinical examination of your dog, focussing on the skin lesions in question. At this point they might choose to take samples for testing or trial treatment if the likely cause is obvious. 

Samples of your dog’s skin include skin scrapes, hair plucks and impression smears – these are all examined under the microscope for clues as to what might be causing your dog’s black scabs. Your vet may also want to perform blood tests to look for signs of systemic illness. 

Questions your vet might ask you

Prior to visiting your veterinarian it’s a good idea to have answers prepared to questions that they might ask you. This will not only save you time and money but will allow for faster diagnosis and treatment of the condition affecting your dog. Questions your vet might ask include:

• When did you first notice black scabs on your dog?
• Are the black scabs getting worse or better?
• Is there any obvious cause of the black scabs such as a wound or injury?
• Is your dog scratching or bothering at the black scabs?
• Is your dog otherwise well in themself? Any other symptoms?
• Have you tried any remedies at home for your dog’s black scabs?

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