Noticing dark or black spots on a newly adopted dog’s tongue can look alarming, but in many dogs they are simply normal pigmentation. Much like freckles or birthmarks on human skin, dogs can have areas of extra pigment on their tongues, gums, lips, noses, and other parts of the body.
These spots don’t automatically mean a dog is part Chow Chow, either. Although Chow Chows are famous for their blue-black tongues, dark tongue spots can appear in many other breeds and mixed-breed dogs as well.
What matters most is whether the spots look like ordinary flat pigmentation or whether something has changed. A veterinarian should examine a dark area if it suddenly appears or rapidly enlarges, becomes raised or lumpy, bleeds, ulcerates, or is accompanied by excessive drooling, bad breath, difficulty eating, or trouble swallowing. Oral melanomas and other mouth tumors can sometimes appear dark or pigmented, although they typically present as abnormal masses rather than ordinary flat spots.
If your adopted dog is eating normally and the spots are flat, smooth, and have likely been there for a long time, they are often nothing to worry about.
Still, because you may not know the dog’s full history, it’s worth pointing them out during the next routine veterinary exam.