A prospective observational study was performed to evaluate the validity of some aspects of Chinese tongue diagnosis in dogs, focusing specifically on the proposed relationship between structural abnormalities of the tongue tip and cardiovascular disease. The tongues of 100 randomly selected client-owned dogs of any age, breed, sex, and medical condition were photographed when the dogs were spontaneously panting. Structural abnormalities noted pertaining to the tongue tip, in accordance with Chinese medicine tongue diagnosis principles, included a split tip or curled tip. Out of 100 dogs, 71 had no tongue tip abnormalities and no history of cardiovascular disease, 5 had no tongue tip abnormalities and a positive cardiovascular disease history, and 24 dogs had abnormal tongue tips. This group of 24 dogs with abnormal tongue tips contained an even number of dogs with either a negative or positive cardiovascular medical history. Out of the 100 dogs, 17 dogs had a positive cardiovascular disease history; of these, 70.6% exhibited tongue tip abnormalities. The remaining 83 dogs without a cardiovascular disease history exhibited a much lower percentage of tongue tip abnormalities (14.5%). The difference in cardiovascular disease between the two groups was highly significant, at p<0.0001, according to a Fisher’s exact test. The prevalence of cardiovascular disease among dogs with structurally abnormal tongue tips was significantly greater than that in dogs with normal tongue tips, suggesting that tongue diagnosis may have value as an initial assessment tool.