Final answer:
False. It is not recommended to leave a retained deciduous tooth alone in a pet's mouth without removing it because it can lead to dental problems and complications.
Step-by-step explanation:
A baby tooth that does not fall out on its own and stays in the pet's mouth is known as a retained deciduous tooth. Retaining a deciduous tooth in a pet's mouth without extracting it is not advised. This is due to the fact that it may result in a number of dental issues and complications. The overcrowding caused by retained deciduous teeth can cause the permanent teeth to become misaligned. Tooth decay, gum inflammation, and plaque and tartar accumulation can also result from it.
As a result, it's crucial to speak with a veterinarian who can evaluate the circumstances and recommend the best course of action, which is usually extraction of the retained deciduous tooth.