Why does my 8-month-old dog have new brown spots on his skin?

This looks like normal pigmentation to me however it could also be post inflammatory hyperpigmentation from an infection. I wouldn’t be overly worried but I suggest you use these medicated wipes on the pigmented areas daily for 7-10 days. If no change then it’s either normal or you should have your vet check it. ( https://www.allivet.com/p-5393-douxo-chlorhexidine-3-ps-pads-for-dogs-and-cats-30.aspx )

Your pictures aren't coming in clear on my end. It could be normal pigmentation of the skin (even white dogs can have non-white skin), flea dirt, or signs of inflammation. To be sure, you can have your vet take a look.

Thanks for your question. Unfortunately the picture that was attached is quite blurry and makes it difficult to see anything when it is enlarged. In the smaller image, all I can see appears to be normal pigmentation spots. If there are smaller spots that aren't visible in this photo you may want to try to post a new picture.

Unfortunately, it's impossible to be sure from a picture, but the area looks like normal pigmentation on the skin. Young dogs often develop darker areas on their bellies as they get older, so the area may continue to enlarge. If the area is irritated, red, bumpy, crusted, or appears different from the surrounding skin in any way other than color, I would have your veterinarian examine it, but I suspect that it is just a big ol' stomach freckle! I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

There are several reasons this can occur. Try washing Henry with an antibacterial dog shampoo once a week. If this doesn’t help after a couple weeks or if it gets worse, have him seen by his veterinarian to check for skin mites, fungal infections (some of which humans can get) or allergies. Of course you don’t have to wait and you can have Henry checked at any point. I hope this is helpful and please feel free to post any additional questions.

It's difficult to say based on pictures along. Your second picture almost looks like a nipple, but I'm assuming this is not the case if more and more have been noted. Sometimes a bacterial skin infection can cause darker skin and a raised lesion, and skin infections can be common secondary to allergies. It's also possible that these are normal areas of pigmentation. I would recommend having your vet examine Luna's skin.

Thank you for using Petco Pet Education Center, formerly Petcoach. Many dogs normally have darker pigmented areas of skin under their fur. In some dogs, this does pigment can increase with age. It is impossible to tell only from a photograph however if this is normal pigment. She would need to be assessed by a veterinarian with a physical exam to determine if there is cause for concern.