Why are My Dog’s Gums Swollen in Boxborough, MA?

Gingivitis, gingival enlargement or gingival hyperplasia are medical conditions in which a dog’s gum tissue becomes inflamed and enlarged. When a dog’s gums are swollen, it is typically caused by irritation due to dental plaque or other bacterial growth along the gum line.

Periodontal Disease

Periodontal disease is something that affects many dogs. Here are some things to know about how it affects your pet.


Gingivitis is considered the earliest stage of periodontal disease. It is also the only reversible stage of periodontal disease. When it is in the early stages, there is some plaque present along with a mild redness of the gums. As gingivitis progresses, there is an accumulation of more bacteria which releases toxins and destroys the gums.

Plaque and Calculus

When gingivitis advances, there is plaque and calculus under the gums that causes severe redness of the gums. Plaque is considered a collection of food, debris, bacteria, dead skin cells, and mucous that forms within 24 hours on a clean tooth surface. Dental calculus is calcium phosphate and carbonate mixed with organic matter. A dog’s gums respond to plaque with inflammation of the blood vessels, swelling, and collagen loss.

Advanced Gingivitis

In cases of advanced gingivitis, your dog’s gums will be very swollen with evidence of bleeding. If it has gotten this bad, it is important to contact your dog’s veterinarian immediately.

If your dog is dealing with gingivitis, you’ll notice that their gums are red and swollen. They may also have bad breath. The sooner you notice your dog’s swollen gums and get them to the veterinarian, the better. Dental disease can progress quickly, so having your dog’s mouth checked out by a veterinarian as soon as possible is always best.

Gingival Enlargement or Hyperplasia

Gingival hyperplasia is a condition of overgrowth of the gum tissue (gingival enlargement). This condition creates deep pockets around the crowns of the teeth which can trap plaque and may lead to periodontal disease. This condition is more common in certain breeds and families, but the exact cause is unknown. Some medications may induce gingival enlargement. It appears that chronic stimulation of the immune system, like that caused by a reaction to plaque, contributes to the condition.

Causes of Swollen Gums in Dogs

An accumulation of plaque is one of the main causes of swollen gums in dogs. There are also some predisposing factors that can contribute to why your dog’s gums are swollen. Those factors include:

  • Old age
  • Crowded teeth
  • Treats and certain foods irritating the gums
  • Open mouth breathing
  • Bad chewing habits
  • Lack of oral health care
  • Uremia and diabetes mellitus
  • Other autoimmune diseases

When plaque is not removed from a dog’s teeth with regular brushing, bacteria will persist along the gumline. Minerals in the saliva harden the plaque which then forms as tartar. When plaque and tartar accumulate, a dog’s gums will begin to swell and recede.


Another condition in dogs that can cause swollen gums is stomatitis. Stomatitis refers to a more generalized, severe and painful inflammation of the mucous membranes within a dog’s mouth and may include the gums, tongue, lips, and/or the roof or floor of the mouth.

The cause of stomatitis is unknown but may be caused by a hyperimmune response of the gum tissues to a bacterial biofilm. Stomatitis may be associated with the development of dental disease.

Stomatitis may be managed medically or treated surgically. However, the prognosis for stomatitis varies depending on each dog’s specific situation.

Dog Oral Hygiene is Important

Not having proper oral hygiene can affect your dog’s gums. It is just as important for dogs to have good oral hygiene as it is for humans. You can brush your dog’s teeth at home, or you can take them to the vet to have it done.

Diagnosis of Swollen Gums in Dogs

Your veterinarian will need to perform a physical exam on your dog before anything can be diagnosed. It will be important that you can give your veterinarian a thorough history of your dog’s health and when their symptoms started. Your veterinarian may also want to know what your dog typically eats, whether your dog has had any trouble eating or chewing, and whether your dog has had any previous health conditions.

Veterinarian Exam

You will also want to share with your veterinarian the routine and products you use to keep your dog’s teeth clean. During the physical exam, your veterinarian will closely examine your dog’s mouth to identify what is going on. Your veterinarian may then have you schedule an appointment to bring your dog back in for a teeth cleaning under general anesthesia.

Dog Teeth Cleaning

During a dog’s teeth cleaning, your veterinarian can check the depth of the gum pockets as well as the amount of plaque and bacteria on the surface of your dog’s teeth. While under general anesthesia, it will be easier for your veterinarian to go ahead and pull any teeth that are rotten or that are too crowded.

A deep and thorough cleaning will be performed on your dog’s teeth at this time. Using special dental equipment, your veterinarian will remove any plaque and calculus. The tooth surfaces will be polished, and the teeth will be reexamined after cleaning.

Treatment of Swollen Gums in Dogs

There are different options to help treat your dog’s swollen gums and prevent it from coming back.

At-Home Teeth Cleaning

You can help maintain your dog’s oral health care by brushing their teeth on a regular basis – ideally every day. There is also a veterinary antibacterial solution your veterinarian can give you to squirt on your dog’s teeth to decrease plaque buildup. Various chews, mouth rinses and water additives, as well as specialized dog food can reduce tartar and improve your dog’s oral health as well. Consistent daily oral health care along with regular annual checkups at the vet will ensure your dog has a healthy and clean mouth.

We recommend products that have been awarded the VOHC Seal of approval. The Veterinary Oral Health Council authorizes the use of the VOHC Registered Seal on products indented to help retard plaque and tartar on the teeth of animals.

Professional Dog Teeth Cleaning

Scheduling an appointment for a thorough teeth and gum cleaning under general anesthesia is the best solution if your dog is experiencing swollen gums due to gingivitis. Dogs typically recover uneventfully from a deep teeth and gum cleaning. However, your veterinarian may recommend you soften your dog’s food for a day or two due to gum sensitivity. Daily oral care will be the best way to prevent your dog from having any more mouth issues.


It is unusual for a veterinarian to prescribe antibiotics to treat swollen gums or for antibiotics to resolve gum disease. The sooner you notice swelling in your dog’s gums and get them to the vet, the better. The earlier your veterinarian can begin treatment, the less likely it will be for your dog’s gum and teeth issues to worsen.

Veterinary Dental Services Can Help

If your dog has swollen gums or you want to know more about dog teeth cleaning, Veterinary Dental Services can help. Give us a call at (978) 929-9200!