Spots on chest

[Rufus22]

I’ve noticed some spots appearing on the skin underneath white chest fur of my 4 mo. old puppy.

Does any one have any idea what this might be?

He does itch a lot, and we’re considering getting allergies test done to get to the bottom of itching. Can the spots be related to itching?

Thanks in advance

[zeta1454]

If you are referring to the darker patches on the skin, it could be ‘hyperpigmentation’ which is really a symptom of something rather than a condition in it’s own right and would really need a vet assessment before you try any treatment or even perhaps before allergy testing. Itching can be due to a range of different causes and is not necessarily due to an allergy.

Regarding the skin patches (if they are hyperpigmentation), there is more information on this web page from a specialist vet:

“Generally speaking, hyperpigmentation is a secondary condition, thus it is a secondary effect. It happens most often when there is trauma to the skin for any reason. Skin inflammation such a redness of skin or scratching the skin are common causes of skin trauma.

When such skin trauma occurs, the skin repair cycle is activated. Part of skin repair involves increased melanin pigment as a protective effect for superficial skin layers. When this protective melanin pigment accumulates in the skin layers, skin is visibly darker to see. Causes such as skin allergy in dogs, scratching, skin infection due to bacteria, skin inflammation due to skin parasites, and self-trauma by dogs with activities such as scratching, rubbing, licking, and biting at their own skin are commonly seen in dogs with skin problems. These all can lead to hyperpigmentation.

Sometimes darker skin, i.e. hyperpigmentation of the skin, may occur after a skin problem has already occurred and the skin is healing from previous trauma to itself.

Other causes of hyper pigmented skin in dogs include breed-specific variations, hormonal disorders such as hypothyroidism or Cushing’s disease, effects of medications, physiological changes, etc. When other skin lesions such as hair loss or skin redness are evident, these signs are typically more helpful in finding the cause of the skin changes and correcting the signs including hyperpigmentation.

It is always key that the underlying skin problem is diagnosed and corrected as almost always, a dog with skin-related changes will have an underlying cause for it. Such underlying causes are best evaluated by a veterinary dermatologist or a family veterinarian so that it can be determined how the hyperpigmentation occurred and what would be the best treatment for the associated symptoms and causes.“

https://www.vetdermclinic.com/what-is-h ... condition/