Why did my dog's pink belly turn dark? Is it age, heat, or a problem?

This looks like hyperpigmentation. It typically occurs in lightly pigmented, sparsely haired regions as dogs get older. It can also be caused my inflammation so just make sure she is not spending too much time sunbathing and that there are no other signs like licking/scratching/lesions. I hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach!

The pictures look like it could just be normal pigment change. As puppies mature their pigmentation can as well. If the skin is raised, thicker, crusty, or itchy then I would be concerned. If you have any concerns then I would encourage you to have him evaluated by your veterinarian. If there is a concern then a biopsy could easily be done at the time of his neuter. Best of luck and thank you for using Pet Coach.

Hyperpigmentation of the skin is common with age where there is no overlying hair. It can also be caused by skin irritation/infections but if there are no lesions or symptoms it is likely normal. No treatment needed in that case. I hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach!

That may be just normal pigmentation changes. If the skin feels, or looks rougher than normal, if there are scabs or if she itches those areas then I would be more concerned. I hope this was helpful!

Hello, and thank you for your question! Darkening of the skin should not be a problem, in the absence of any scratching or irritation. However, terriers such as westies can be prone to skin allergies, so I would keep a close eye on Britta for any licking, biting or scratching of her skin. If so, this irritation could cause darkening ("hyperpigmentation"), and if so, I would recommend taking her to the vet for an exam of her skin. On the topic of westies with sensitive skin, I would stick with bathing her no more than once a month, using a gentle aloe and oatmeal based shampoo. Rinse thoroughly with lukewarm water. This will help to prevent overdrying and itching of the skin. I hope this helps, and that Britta is doing well!

This may be a natural pigment change as he develops or may be related to a skin irritation such as from demodex mites or a yeast infection. If there is no heat, discomfort or itching of the area continue to monitor closely - your vet or vet nurse could take a look to put your mind at ease and advise if any investigation or treatment is recommended

I would recommend reverting to his original food or a hypoallergenic diet and adding some omega fatty acids to promote skin repair and regeneration. If the diet has triggered these symptoms, they should regress over 6-8weeks. If he develops severe itching, antiinflammatory sprays or gels may be required from your vet. Seasonal allergies are also very common at this time of year and tend to develop in younger dogs (usually between 6mths and 3 yrs for first symptoms)