My senior dog has a crusty black growth on her back. Is it serious?

It sounds like this is some kind of skin growth. Dogs can develop melanomas of the skin along with many other benign growths. I would recommend having your vet take a look - they might recommend taking a sample with a small needle to determine what this might be, or they might recommend going ahead and removing it.

A black crusty lump could be a sebaceous gland tumor (usually benign), a papilloma, or a cancerous mass. Skin lesions can sometimes be identified just by looking at them. Do have your vet or one of the experts here to look at it first. If it can't be identified then having this mass biopsied and analyzed will lead to a proper identification. I hope this helps!

I would guess that these are sebaceous adenomas or benign skin growths that are common in older dogs. There are some other skin tumors that could look similar however and it would be best to have your veterinarian examine Linguine in person to be 100% sure.

From your description of the darker patch it sounds like another patch of hyper pigmentation due to old age. Melanoma (a type of tumor) could potentially start with this type of hyper pigmentation though and evolve in a proper growth. A picture of it would be extremely helpful, but it can be shown to us only by requesting a consultation. Otherwise a check up would be needed.

Unfortunately some of these cysts and adenomas do tend to rupture and become infected repeatedly. If that is the case we often do recommend removal to avoid this continuous cycle. It may also be advised to remove it to ensure that it is a benign adenoma and not something more concerning or aggressive.

That appears to be a sebaceous adenoma - a benign skin growth. These are not concerning but can sometimes bleed or become infected. In that instance, it should be removed if it is causing constant issues.

Thank you for the image. This is likely a benign skin mass known as a sebaceous adenoma. They are common in older dogs and arise from sebaceous glands in the skin. You would need to have your dog physically examined by your veterinarian for confirmation. Removal is recommended if the lump grows larger or becomes ulcerated, but others may grow in the same spot or different areas. Keep it clean and dry and be careful not to irritate it during grooming/brushing or bathing.