St. Bernard puppies typically begin losing their baby teeth and getting their adult teeth around the age of three to four months. It's quite normal for these deciduous teeth to fall out unnoticed, sometimes in a hidden spot or even swallowed by the pup. During this period, it's important for pet owners to carefully observe their puppy's condition and provide appropriate dental care.

While the general timeframe for St. Bernards to start losing their teeth is between three and four months, there can be slight variations among individual puppies. The teething process usually spans a few months, with most puppies completing their adult tooth eruption by the time they are around nine months old. During teething, it's common for puppies to chew on things, which is a natural way for them to relieve the discomfort or itchiness in their gums. Instead of scolding them, providing appropriate chew toys like dental chews is an ideal way to redirect their chewing habits. Generally, by the age of one year, St. Bernard puppies have a full set of permanent teeth, which may have small pointed tips on the incisors. Loose baby teeth that have been swallowed are harmless because they are small and will be broken down by the stomach's gastric acid and digestive enzymes. It's crucial to avoid feeding soft food during the teething phase as it might prevent teeth from falling out and it can increase the risk of tartar buildup.