Dog’s Belly With Black Or Brown Spots: a Reason to Worry? [Vet Advice]

If you’ve recently discovered a new dark spot on your dog’s belly, you’re likely scared for your dog’s health. In my veterinary practice, I’ve commonly seen dark black or brown spots appear on a dog’s belly or stomach, but are these new spots an indication that something serious is affecting your dog? 

Luckily, most cases of bellies turning black or brown are nothing to worry about. However, these new spots could also indicate a more serious health issue. In this article, we will review when belly color changes are benign, and when they can be a reason to be concerned.

My dog’s belly turned black or brown, should I be worried?

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, as shown in the picture below:

For other dogs, dark spots can develop on their bellies as they age. In the picture below, you can see the natural “pink” color of the dog’s stomach next to a darker brown area that developed with age. Both colors are normal. 

Beyond aging, black or brown spots on your dog’s belly or stomach can be the result of other benign reasons such as sun exposure, environmental changes, or new medications.

If your dog recently started a new medication or if you’ve noticed a gradual increase in dark spots as your pup has aged, these are likely NOT a cause for concern. Keep an eye on these new spots for any sudden changes in size, shape, texture or color, and see your veterinarian if you’re at all concerned. 

Why would a dog’s belly skin turn dark with black or brown spots?

Melanin is a dark pigment that can be found in your dog’s skin and coat. The more melanin your dog has, the darker their skin and hair. When dark pigmentation clusters together, it can create a dark black or brown spot wherever the clusters occur—like your dog’s stomach.  

In typical cases, this clustering of melanin is caused by aging or sun exposure. Time, sunlight, or other environmental factors can traumatize your dog’s skin cells, putting them into repair mode. 

When this happens, the melanocytes in your dog’s skin produce more melanin than usual to protect your dog’s damaged and vulnerable areas. As the melanin accumulates, you can find more dark, black, or brown-colored spots on your dog’s body.

The trouble happens when something less common damages your dog’s skin cells, like infection, inflammation, or an underlying health condition. These create chronic irritation or damage to the skin that also increases the accumulation of melanin. Getting that inflammation under control may require treating the underlying condition. That’s why it’s important to have your vet check out any new changes to your dog’s skin, especially if those changes are accompanied by other signs as well.

How to tell if your dog’s belly color changes need veterinary help

While the spots on your dog’s belly are likely normal, changes to their skin color can also be the result of a medical condition that needs veterinary intervention. Let’s review now how you can find out if your dog’s belly color needs veterinary help.

The most frequent medical conditions that can cause a dog’s belly to change color include:

• Skin infections or irritations
• Allergies
• Parasites
• Injuries
• Endocrine disease or disorders such as hypothyroidism

Other, less common reasons your dog’s belly could change colors are Cushing’s disease, external environment changes, and cancer. 

If you notice changes in your dog’s belly color, monitor these changes closely. If the spots aren’t bothering your dog, continue to monitor their behavior, but contact your vet immediately if the colors change in size or shape. 

Redness, itchiness and changes in textures can also be signs of a skin infection or irritaion. Call your vet if your dog’s belly skin appears to be:

• rough, scaly, or crusty
• red around the area
• itchy

The three pictures below show examples of dog bellies with rough, crusty or red areas (besides black or brown spots on the belly). This indicates that an underlying medical condition is causing these skin issues and spots:

+
Note that the examples above show fairly serious cases. If your dog’s belly is showing any signs of irritation or itchiness – even when it’s not as dramatic as the examples above – you should still consult with your vet to make sure that the condition doesn’t get worse for your dog.

Your dog may also require veterinary help if they experience: 

• a change in behavior
• a change in appetite
• a change in activity level (for example, if your dog is not as energetic as usual)

Checking in with your vet

Even if the black or brown spots on your dog’s belly haven’t changed in size, shape or texture and your dog’s behavior seems normal, you should still check in with your veterinarian during a routine exam. Your vet will likely be able to evaluate if the spots are a serious issue.

If your vet is uncertain about a diagnosis, they may request a sample from your dog. This typically involves a skin scraping, fine needle aspirate, or even a biopsy of the brown or black spots. From there, treatment will be started, if necessary, depending on the cause. Look to spend anywhere from $100 to $300 for diagnosis.

What is the Treatment for Black or Brown Spots on a Dog’s Belly?

Most cases of black spots or brown spots on a dog’s belly won’t need treatment. They could be a normal part of aging or sun exposure. If the spots are showing up because of irritation related to allergies, infection, or parasites, those conditions will need to be treated in order to prevent further color changes and damage to the skin.

If the skin changes on your dog’s belly are due to an endocrine disorder or something like Cushing’s disease, you’re going to notice an array of other signs, including weight gain, increased appetite, hair loss, and cold intolerance to name a few. These issues will require more extensive diagnostics and lifelong treatments. This just goes to show that you don’t want any changes in your dog’s skin to go undiagnosed and treated.