Has your dog’s usual pink tongue color faded somewhat? Take her to the veterinarian. A tongue or gums that go from pink to paler pink could be a sign of anemia — a deficiency of red blood cells — and the cause has to be identified and treated. If her gums or tongue literally go grey or bluish-grey, get her to the doctor right away. She could be suffering from oxygen deprivation — perhaps because of heart disease or a lung problem.
Try doing a capillary refill on your dog. Press a finger on her gums. When you remove it, the gums should be white but return to their normal pink color within a couple of seconds. If they don’t, something may be wrong with her blood flow. There may be too little blood, or too little oxygenated blood.
While you can’t do a capillary refill test on a dog with black gums, you can check for pink tissue on the inside of the lower eyelid by gently pulling the lid down.
