Most mouth problems can be identified by inspecting the lips, gums, teeth, and throat. To open the mouth, slip a thumb into the space behind the canine tooth and press upward on the roof of the mouth. As the mouth begins to open, press down on the lower jaw with the opposite thumb. To see the throat and tonsils, depress the tongue with a finger.
Another method is to gently squeeze in from the top of the dog’s muzzle, right behind the whiskers, with your thumb and forefinger. As the mouth opens, separate the top and bottom jaws with your fingers.
To examine the dog’s bite (also known as occlusion), close the mouth and raise the upper lip while drawing down on the lower lip with your thumb. The bite is determined by seeing how the upper and lower incisor teeth come together.
Raising the lips also exposes the mucous membranes of the gums. The appearance of the gums gives an indication of anemia and the state of circulation. This is easiest to evaluate in dogs with pink gums (as opposed to pigmented gums).