Are Chow Chows the only dogs with black tongues?

No, Chow Chows are not the only dogs with black tongues, but they are one of the few breeds known for this distinctive trait. Some other breeds may also have black spots or patches on their tongues, but a fully black tongue, as seen in Chow Chows, is relatively rare. Other breeds known to occasionally have black tongues include the Shar-Pei and some mixed-breed dogs.