When an old dog’s teeth begin falling out, whether one tooth at a time or several in a short period, it can be alarming.
Tooth loss in senior dogs is common, but it almost always reflects an underlying dental or health issue that needs attention.
We outline the common reasons why an old dog’s teeth may start falling out what you can do and seeking veterinary help.
Old Dog Teeth Falling Out: Why It Happens
An old dog’s teeth falling out is usually caused by advanced dental disease, gum inflammation, infection, trauma, root decay, nutritional issues, or medical conditions that weaken the mouth’s structures.
Senior dogs rarely lose teeth without a meaningful reason — and tooth loss can affect eating, comfort, behavior, and overall health.
Old Dog Teeth Falling Out: Common Causes
Advanced Periodontal Disease
Periodontal disease is the number one cause of tooth loss in older dogs. Over the years, plaque and tartar accumulate, pushing bacteria underneath the gums.
This leads to inflammation, gum recession, and eventually, destruction of the bone that supports the teeth.
As the bone and connective tissue weaken, teeth loosen and eventually fall out. Many senior dogs tolerate chronic dental disease quietly for years until tooth loss becomes obvious.
Signs often include bad breath, drooling, difficulty chewing, or dropping food. When periodontal disease progresses to its later stages, even gentle pressure on a tooth can cause it to detach.
Tooth loss from periodontal disease is progressive, meaning more teeth may fall out if treatment is not provided.
Read more: Old Dog Bad Teeth (Causes explained)
Severe Gum Inflammation or Infection
Gingivitis and gum infections are major contributors to tooth loss in older dogs. Chronic inflammation weakens the tissue holding the teeth in place, leading to loosening and eventual shedding.
Infection can form around the tooth roots, creating abscesses that damage surrounding structures. These infections are often painful and may cause swelling, bleeding gums, or reluctance to eat.
Because older dogs have weaker immune systems, gum infections can progress rapidly and cause significant damage before owners notice.
When inflammation becomes severe, the gums cannot support the teeth, causing them to fall out or break at the root.
Tooth Root Abscesses
A tooth root abscess occurs when bacteria invade the center of the tooth, often through cracks, gum recession, or advanced decay.
The infection builds pressure at the root, destroying the bone and connective tissue that hold the tooth in place.
As the abscess enlarges, the tooth becomes unstable and may fall out or require extraction. Abscesses can cause swelling under the eye, foul smell from the mouth, drooling, or sudden refusal to eat.
For senior dogs, tooth root abscesses are especially problematic because the surrounding bone may already be weakened from years of dental disease, making tooth loss more likely.
Trauma or Injury to the Mouth
Older dogs may lose teeth due to trauma, even minor incidents such as chewing hard objects, falling, or experiencing pressure to the jaw. Aging teeth are more brittle and prone to cracking or breaking.
A broken tooth may eventually fall out or need removal if the root becomes exposed. Dogs that have lost bone density due to age or illness may lose teeth more easily from everyday chewing.
Injuries often go unnoticed until a tooth is missing or the dog suddenly shows discomfort during meals.
Nutritional Deficiencies
Poor nutrition — especially deficiencies in calcium, essential vitamins, and minerals — can weaken teeth and gums over time.
Senior dogs with digestive issues or chronic illness may not absorb nutrients efficiently, leading to weaker tooth structures.
Malnutrition accelerates bone loss in the jaw and makes teeth more susceptible to falling out.
Dogs that have been fed poor-quality diets for many years may experience earlier or more severe tooth loss as they age.
Underlying Medical Conditions
Certain medical conditions make old dogs more prone to tooth loss. Diseases such as diabetes, kidney disease, liver disease, and autoimmune disorders can impair gum health, reduce saliva production, or alter the mouth’s natural bacteria.
Dry mouth, in particular, contributes to rapid tartar buildup and gum recession. Hormonal imbalances like Cushing’s disease may also weaken connective tissues, increasing the risk of tooth instability.
Dogs with cancer or bone disease may lose teeth when the jaw becomes fragile or weakened. These conditions often progress quietly, with tooth loss becoming one of the first noticeable symptoms.
Old Age and Natural Wear of the Teeth
Even without disease, an old dog’s teeth undergo years of mechanical wear. Grinding, chewing, and playing gradually wear down enamel, making the teeth more vulnerable to cracking or loosening.
As supportive tissues naturally decline with age, some teeth may simply not withstand everyday use anymore. While this cause is less common than disease, age-related wear often contributes to tooth loss in combination with other factors.
Dogs with naturally small or crowded teeth may be more susceptible as they reach advanced age.
Read more: Old dog teeth rotting out (Here’s why)
What to Do If Your Old Dog’s Teeth Are Falling Out
Begin by checking your dog’s mouth carefully — without forcing it open — to see whether there are signs of redness, swelling, bleeding, or missing teeth.
Softening meals can help reduce discomfort during eating, such as offering wet food or soaking kibble in warm water. Avoid giving hard treats, bones, or toys that could worsen pain or cause additional tooth loss.
Keep your dog’s water fresh, as hydration helps reduce inflammation. Monitor appetite, chewing behavior, and any signs of pain around the face or jaw.
Because tooth loss is almost always the result of disease or underlying health problems, schedule a veterinary dental evaluation as soon as possible. Early treatment can prevent further tooth loss and relieve discomfort.
When to Call or Visit Your Vet
Seek veterinary care if your old dog’s teeth are falling out and you notice:
• Bad breath, drooling, or difficulty chewing.
• Bleeding or swollen gums.
• Loose teeth or sudden tooth loss.
• Refusal to eat or dropping food.
• Pawing at the mouth or face.
• Swelling under the eye or around the jaw.
• Weight loss or lethargy.
• Blood or pus coming from the mouth.
• New or worsening pain during meals.
• Any sudden or progressive changes in dental health.
Tooth loss in a senior dog is always significant and should be evaluated promptly.
Key Takeaway
When an old dog’s teeth begin falling out, it is almost always due to dental disease, gum infection, abscesses, trauma, or underlying medical conditions.
While tooth loss is common in older dogs, it should never be ignored — it offers valuable insight into your dog’s overall health.
With proper veterinary care, dental cleaning, pain management, and supportive feeding, you can help your senior dog live comfortably even with missing teeth.