Bad odor from the mouth can have different causes. However, there is often a gum infection with tartar behind it. This tartar absolutely has to be removed by the vet otherwise the gum can be pushed back so far that the teeth can fall out. If the teeth are clean again, the new formation of tartar can be reduced or prevented completely by various care measures for the teeth. The best care is provided by brushing the teeth with special dog toothbrushes and dog tooth paste. Brushing the teeth two to three times a week can strongly reduce the formation of tartar. If the dog does not allow brushing of the teeth even with careful training, you can offer him special tooth cleaning strips, raw hide bones or raw carrots as an alternative which care for the teeth during chewing.Have your dog's teeth checked regularly (e.g. when getting annual shots) so that tartar can be removed on time and no gum infections occur.