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Dark Spots on Dog’s Belly (Reasons and Solutions)

Only dog people can comprehend the joy of petting the dog’s tummy after a long, hard day. However, a sudden darkening belly can stir some concern in dog dads and moms. In most instances, this darkening can be identified as hyperpigmentation.

Hyperpigmentation is a condition where special skin cells produce too much melanin in a particular area.

It is an indication of underlying symptoms rather than a disease. Hyperpigmentation itself is very harmless but if is associated with other symptoms, it can be a signal point to identify something is wrong.

Dark spots on dog’s belly

The most common cause of hyperpigmentation on dogs is trauma or traumatized skin. Other reasons include endocrine disorders, allergic reactions, aging, infection, and cancer. When hyperpigmentation is associated with itching, redness, and rash, it indicates traumatized skin.

Hyperpigmentation has two branches_ Primary and secondary. Primary hyperpigmentation is rare and breed-specific.

It is manifested within one year of birth and is not curable but manageable. On the flip side, secondary hyperpigmentation can affect any and all kinds of breeds. 

Here’s a list of reasons why your dog might have a dark belly as a secondary hyperpigmentation cause.


In the case of allergic reactions in dogs, chronic itching becomes the number one symptom. Excessive itchiness leads the dogs to scratch, chew or lick the belly area which eventually leads to bacterial or fungal infection.

The darkening doesn’t happen overnight and you might notice a dark belly after 3-4 months of the allergic reaction.


Some dogs might have an inherent tendency for darkening skin as they grow older.

If the cause is due to aging, there will be no other symptoms accompanying like thickening skin, odor, or hair loss. The dark patches will not be scaly or itchy either.


Dog skin can be infected by different types of infections_ yeast, bacteria, Demodex, ringworm, etc. This causes irritation on the skin and hyperpigmentation.

Usually, the skins are thickened, dark spots become itchy and a circular pattern of hair loss can be seen.

Endocrine disorder:

Hypothyroid or sex hormonal imbalance, any type of endocrine or hormonal disorder may cause dark, patchy spots on a dog’s tummy.

This symptom is associated with hair loss, loss of appetite, or chronic urination. If the hormonal disorder is not resolved, the symptoms will not disappear.


Dermatitis is the result of flea allergy, food allergy, or contact and inhalant allergy. It causes inflammation, rash, chronic itchiness, thickening skin, and of course, hyperpigmentation.

Dermatitis causes pain and uncomfortable living for the dogs and their appetite and ability to rest are greatly hampered.

Habitual licking:

Dogs have a habitual tendency for excessive licking on the groin area. This leads to hair loss and thickening skin. The contact of saliva bacteria on the belly stirs up the melanin in the body and makes the skin dark and patchy.

Post-inflammatory hyperpigmentation:

It is one of the leading causes of the dark belly. In case of inflammation, an excessive amount of melanin is produced in the body. Thus, after an injury or fungal and bacterial invasion, this darkening is a common cause.

This is associated with circular or focal hair loss, loss of appetite, and patchy, bald spots on the tummy.


Hyperpigmentation in the belly area can be a sign or indicator of cancer cells as well. Melanoma skin masses can be malignant or benign.

If it is malignant, the chances of cancer are sky-rocketing. Usually, in this case, the darkening spreads out in the whole body.

Is it normal for dogs to have dark spots on their belly?

Dark spots can be normal in dogs, especially in areas of friction such as legs and bellies. Due to aging and excessive melanin, dogs grow dark spots in the belly area, which is normal and safe.

However, if the dark spot grows bigger and comes with other underlying symptoms, you must pay the vet a visit.

To eliminate the concern about the dark, it is recommended to get the dog a thorough check. Hyperpigmentation is not a disease but a symptom of something atypical. Your dog’s body is trying to communicate about the abnormality through this symptom.

You must check the other symptoms like loss of hair, rash, and itchiness, with hyperpigmentation. If the body is signaling these symptoms, there sure is a reason to be concerned.

But if the dark spot is not growing and your breed has a tendency for hyperpigmentation, it is very normal.

What do black spots on dog’s skin mean?

Black spots on your dog’s skin can mean that your dog is aging or it has an allergic reaction that is causing trauma in the skin cells.

It can mean your dog is a breed that is prone to hyperpigmentation. In these cases, these breeds manifest harmless dark spots in the groin and belly area.

If the dark spots show due to aging or breed-specific, your dog is safe and sound. The concern appears when there are other underlying symptoms associated with hyperpigmentation. Those can mean that your dog might need a check-up.

The most common cause of dark belly is traumatized skin. It can be due to an allergic reaction, dermatitis, flea infection, and so on.

Some other symptoms like thickened skin, bald and patchy spots, redness, chronic itching, and hair loss can also indicate that your dog is having health issues.

It is not unusual that a dark spot on a dog’s belly can mean cancer. One of the first symptoms of cancer cells is hyperpigmented skin. This is more crucial in cases of some special breeds.

It can also mean that some food, medication, and supplements are not digestive to the dog’s immune system. After an injury or infection, excess melanin is produced due to an active immune system.

No matter how benign or pressing the issue is, it is wise to get checked by a professional and drag out the latent cause of these dark spots.

How do you treat dark spots on dog’s skin?

When you spot darkened skin on your dog’s belly, it is wise to take immediate action. Since hyperpigmentation doesn’t happen overnight, it can already be too late and your dog can develop some disease or reaction.

The first and foremost duty is to diagnose the underlying cause behind this dark spot.

After diagnosing the cause, follow the methods mentioned under to treat your dog’s dark spots and hyperpigmentation.   

Allergic reaction:

If the dark spot is a symptom of an allergic reaction, you must get a specific chart from your vet of which foods, medications, and supplements your dog is allergic to.

Also, you must ensure the environment your dog lives don’t stir up any allergic reactions.


Whether bacterial or fungal, you must identify the particular organism that is causing hyperpigmentation.

Then you can need to find a suitable ointment to remove the effect. You can choose medication to eliminate the fungus or bacteria internally.

Endocrine disorder:

Hormonal imbalances can be really uncomfortable for dogs and their lifestyle. Instead of eliminating the dark spot, diagnose the misbalancing hormones. Treatments will be required to get the hormone levels to normal. Once the levels are normal, the dark spots will also fade away.


The most common dermatitis is flea allergy. Thus, you must take steps to make your dog’s fur flea-free. Your dog might need shaving or special shampoo to shoo those fleas away.

Once your dog stops licking or chewing the spots, the dark spots will eventually fade away.

Post-inflammatory hyperpigmentation:

Usually, once the dog is off the medication for inflammation and back to its normal diet and lifestyle, the dark spots eventually fade.

If the spots don’t come off, you can consult your vet for special medicine. However, this doesn’t pose any threat if the other symptoms don’t appear. 


If the melanomas are identified as malignant, the safe option is surgery. Since the tumor is aggressive and spreads fast in the body. It may also require chemotherapy, post-surgery care, and radiation.

If the melanomas are benign, the usual treatment for fading hyperpigmentation will suffice.

Final thoughts

The reason for dark spots on a dog’s belly can be benign or a symptom. For health safety, you must diagnose your dog so that the underlying cause of such hyperpigmentation can be unraveled. Treating without diagnosis may deteriorate the condition and hinder the dog to lead a healthy life.