This article was updated on May 8th, 2023
Black Spots: Introduction
Dogs are such an important part of our lives and our families. It can be scary when a pet parent finds a new lump, bump, black spot or dark spot on their dog’s skin. One condition that I commonly see in my veterinary practice is discolored, dark, black or brown spots on the skin. This often happens on a dog’s belly or near their genitals but could also happen anywhere on your dog’s skin.
Why does a dog’s skin turn black?
When the dog’s skin is traumatized, the skin cells go into repair mode. In this process, the melanocytes produce and release more melanin than normal in an effort to protect the damaged and more vulnerable skin. As the melanin accumulates in the skin, the result is dark or black-colored spots.
Though allergies, parasites, injuries, and other skin conditions are the most common cause of hyperpigmentation and black spots in dogs, there are other causes. These include:
- specific breed characteristics,
- endocrine disorders such as hypothyroidism or
- Cushing’s disease,
- external environment changes, and
When Black Spots are Likely NOT a Reason for Concern
If the darkened areas are mild and slowly darkening to black, with no change to the texture of the skin, it is likely that the dog has benign hyperpigmentation of age. This can be a normal part of the aging process for your dog. Below is a picture of normal hyperpigmentation on the abdomen of a 5-year-old dog:
Dogs may also have natural black spots or patches on their skin. The picture below shows black spots as a normal part of the dog’s skin coloration:
Hairless dogs like the Chinese Crested and Mexican hairless will often show hyperpigmentation due to exposure of the skin that is not protected by hair (as shown on the picture below).
If the spots are black and loose on your dog’s hair and skin, it could also be fleas or flea dirt, as shown below.
Your number one clue that your dog has fleas is that your dog will likely chew, lick or scratch themselves more than usual. If this is the case, read our article: 5 Easy Ways to Tell if Your Dog has Fleas.
When Black Spots Are a Reason for Concern
If your dog has black spots or patches, you may notice other changes to the skin. Though dark spots can be the only change, the affected skin will also often change texture or become itchy (read our article about “Itchy Black Spots on Dogs“). The skin with the dark spots may also become:
- red around the area,
- itchy, or
In the picture below, dark spots on this Shih Tzu can be seen with a red rash on the dog’s skin:
The picture below shows a dog with dark black patches, as well as other signs of disease including redness, hair loss, and a rough skin appearance:
Many of these changes can be the result of a medical condition that needs veterinary attention, so we recommend that you consult with your veterinarian to discuss these changes. Let’s now review the top causes of dark or black spots on a dog’s skin, and figure out how to help your dog.
Top Causes of Black Spots (Hyperpigmentation) in Dogs
Most instances of dark or black colored spots on the skin of dogs are hyperpigmentation. Hyperpigmentation is the medical term used to describe an increase of the pigmentation on a dog’s skin when the amount of color is more than what is normal for that dog – often describing black spots on a dog’s skin.
Hyperpigmentation in dogs is usually more of a symptom than a disease in and of itself. Most commonly, the dark or black spots, along with the other signs of redness, scaling, crusting, and itchiness, are a result of trauma from:
Allergies resulting in black spots will typically be accompanied by licking of the feet, red skin, and itching. The black spots themselves will be flat and not raised off of the skin’s surface, as shown on the picture below:
You can click here to view more pictures of dog skin allergy issues with veterinarian explanations.
Parasites, such as fleas and ticks, will typically cause itching as well as biting of the skin. The parasites themselves are often visible on the pet. These dark spots, like allergy spots, will be flat on the skin.
Disclaimer: This content is not a substitute for veterinary care. Always consult with your vet for health decisions. Learn more.
Any irritation or injury to either this skin, or even the underlying bones, joints, and muscles, can result in hyperpigmentation. Typically, these black spots will also be flat on the skin’s surface and will be over or near the injury.
4. Other skin conditions leading to skin irritation and itching
Food allergies, mange, endocrine disorders, skin infections, and autoimmune diseases can all lead to skin irritation that may result in hyperpigmentation and black spots or black patches on a dog’s skin. As hyperpigmentation results from chronic irritation, these spots will lie flat as part of the skin and will not have a mass-like appearance.
What About Dark Spots on a Dog’s Belly?
Black spots on a dog’s belly can be perfectly normal. Some dogs are born with dark spots on the skin as a normal part of their skin coloring. Others tend to develop dark spots on their bellies as they age. The pictures below show two examples of normal black spots or normal dark areas on a dog’s belly:
However, there is a possibility that the spots are a sign of an underlying condition such as skin infection, allergies, endocrine disease, or even cancer, so newly noticed spots should always be brought to the attention of the dog’s veterinarian.
Can Black Spots on a Dog’s Skin Be a Sign of Skin Cancer?
Dark or black spots on a dog’s skin can be an indication of cancer: termed melanoma, these skin masses may be malignant (cancerous and apt to spread) or benign. These are cancers of the melanocytes in the skin that produce melanin.
Though not the case 100% of the time, malignant melanomas most commonly occur in the mouth, around the lips, or on the gums. They can also be found surrounding the toe nails and on the pads of the feet. Malignant melanomas are more commonly found in non-haired areas; however, they can be found in areas of haired skin as well.
Malignant melanomas grow extremely quickly and have the ability to spread to other organs (metastasize). Malignant melanomas usually metastasize to the liver and the lungs in dogs.
The most common breeds to be affected by malignant melanomas are Schnauzers and Scottish Terriers. Being black in color is also a risk factor.
Benign melanomas (also known as melanocytomas) are typically found in areas of haired skin. They may be black or any shade of darker color than the dog’s normal skin. A melanocytoma may be very small or multiple inches in diameter. They tend to grow and change slowly in comparison to the malignant version.
Benign melanocytomas are most commonly diagnosed in Schnauzers, Vizslas, Doberman Pinschers, terriers, and Labrador Retrievers. They are also more commonly diagnosed in older dogs.
Any changes in your dog’s skin should be brought to the attention of your dog’s veterinarian immediately. In many cases, prompt treatment of the underlying cause will cure both the cause and resolve the hyperpigmentation.
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Treatment Options for Hyperpigmentation in Dogs
The first step in treatment is diagnosing the underlying cause. This process can be aided by examining all of the dog’s skin as well as obtaining a thorough medical history. Any itching, licking, parasites, or injuries should be noted.
Skin infections, whether bacterial or fungal, must be identified and treated. Many dogs with these skin ailments also have underlying skin allergies, either to something in the environment or food allergies, and these must be controlled.
Allergies in dogs are just like allergies in people – they cannot be cured. However, they can be managed. If treatment is started and later stopped, the allergic response will often recur, which in turn leads to a recurrence of the hyperpigmented or dark skin.
Endocrine disorders, such as hyperadrenocorticism (Cushing’s Disease) and hypothyroidism, are also lifelong health issues that need to be treated and controlled. These illnesses, if left untreated, will have significant adverse effects on the dog’s health and will drastically shorten their life span.
Malignant melanomas are aggressive tumors and need to be removed surgically. Many cases will require post-surgical cancer care, including chemotherapy, immunomodulation, or radiation.
Preventing Hyperpigmentation & Black Spots in Dogs
Due to the many varying causes of hyperpigmentation in dogs, prevention is difficult. Owners should always treat any allergies, infection, or injuries to the skin promptly and continue treatments as necessary.
UV damage may also play a role in hyperpigmentation, so it is prudent to keep dogs out of the sun as much as possible and when not, to utilize dog-safe sunscreen such as zinc oxide on non-haired areas of skin.
Frequently Asked Questions About Black Spots on Dogs
What does it mean if my dog has black spots that are itchy?
Black spots, or areas of hyperpigmentation, will not cause your dog to itch. It is more likely that your dog has another condition, such as a food or environmental allergy, or parasites, that is causing them to be itchy. The black spots could also be the result of the same condition.
What does it mean if my dog has black spots near her privates?
Black spots near a dog’s genitals have the same causes as black spots in other areas. If the skin’s appearance is changing suddenly and if the dog is licking that area, it is essential to determine the underlying cause. It could have something to do with their urinary or reproductive tracts. The genitals often have skin folds and are also frequently moist, and are ideal places for a skin infection to arise.
Can a dog yeast infection cause black or dark spots?
Yes, yeast infections of the skin can result in black or dark spots. This is due to the chronic irritation of the skin from itching, licking, and the organism living on the skin. Most dogs with yeast skin infections happen as a result of allergies. It is imperative to not only treat the skin infection but also to address and control the allergies to prevent a recurrence.
- Brown Spots on the Skin: Veterinarian Advice with Pictures.
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