Curing Kitty’s Canker Sores. How to Treat Your Cat’s Mouth Ulcers

What Are Cat Mouth Ulcers?

Cat mouth ulcers, also known as rodent ulcers or eosinophilic granulomas, are painful sores that develop in a cat’s mouth, typically on the lips, gums, and tongue. They appear as round, swollen lesions with an eroded or ulcerated surface (1).

The most common locations for cat mouth ulcers include:

  • Lips
  • Gums
  • Tongue
  • Roof of the mouth

Symptoms of mouth ulcers in cats may include:

  • Swelling and redness
  • Bleeding
  • Pus
  • Pain when eating or drinking
  • Drooling
  • Bad breath

Causes of Cat Mouth Ulcers

There are several potential causes of mouth ulcers in cats, including:

  • Injury/Trauma – Cuts, abrasions or puncture wounds in the mouth from foreign objects can lead to ulcer formation. Certain foods like kibble or treats that are hard or sharp can also cause mouth trauma.
  • Foreign Objects – Foreign bodies like plant awns, grass seeds or slivers of bone getting lodged in the oral cavity can cause ulcers. Sometimes cats chew, lick or ingest things they shouldn’t, irritating the sensitive mouth tissues.

  • Dental Disease – Periodontal disease, tooth abscesses and other oral infections are common causes of mouth ulcers in cats. Bacteria from dental plaque and tartar can infect the gums and mouth lining.
  • Viral/Bacterial Infections – Feline herpesvirus, feline calicivirus and other viral and bacterial infections can lead to mouth ulceration. The viruses damage cells, allowing ulcers to form.
  • Cancer – Oral cancer, especially squamous cell carcinoma, can present with non-healing mouth ulcers. Certain cancers cause tissue inflammation that erodes the mucosa.

Identifying the underlying cause is important for treating cat mouth ulcers and providing appropriate care.

Diagnosing Cat Mouth Ulcers

Proper diagnosis of cat mouth ulcers requires a veterinary exam so the lesions can be visually inspected and assessed. The vet will likely ask about the cat’s medical history, including any previous dental issues or procedures (source). An oral exam allows the vet to look for ulcers, abrasions, swelling, and other abnormalities.

If the cause of the mouth ulcers is unclear, the vet may recommend a biopsy to examine the lesions and surrounding tissues under a microscope. This can help rule out serious problems like oral cancer (source).

Imaging tests like X-rays or CT scans may also be used to evaluate the extent of the lesions and see if they extend deeper than the surface. These tests provide important information to determine the best course of treatment.

Treatment Options

There are several treatment options for cat mouth ulcers depending on the underlying cause:

Pain medication – Pain medication like buprenorphine or meloxicam can help relieve discomfort associated with mouth ulcers in cats. These should be prescribed and monitored by a veterinarian as overdose risks exist.

Antibiotics – If a bacterial infection is causing the mouth ulcers, a course of antibiotics may be prescribed by your vet. Common choices include amoxicillin, clindamycin, or doxycycline. Antibiotics treat secondary infections and help ulcers heal faster.

Anti-viral medication – Feline herpes virus is a common cause of mouth ulcers in cats. Anti-viral medications like famciclovir can be used to treat the viral infection and allow the ulcers to heal.

Surgery – In some cases, surgery may be required to remove dead tissue or extract damaged teeth causing mouth ulceration. Your vet will advise if surgical intervention is recommended.

Home care – Gentle salt water rinses, soft foods, and keeping the mouth clean can provide relief at home. Never use human oral care products in a cat’s mouth.

Home Care

There are several things cat owners can do at home to help care for a cat with mouth ulcers:

Soft foods – Feed your cat soft, moist foods that are easy to eat and swallow such as canned food or kitten food. Avoid dry, crunchy kibbles that could further irritate the ulcers.

Ensure hydration – Make sure your cat stays hydrated by providing plenty of fresh, clean water. You can also add some water to your cat’s canned food to make a broth.

Gentle tooth brushing – Very gently brush your cat’s teeth around the ulcerated areas using a soft-bristled toothbrush and cat-safe toothpaste. This helps remove food particles and plaque that can further irritate the ulcers.

Avoid irritation – Do not use plastic food and water bowls, which can harbor bacteria. Stainless steel, ceramic or glass are better options. Also avoid mouthwashes and disinfectants that could further irritate the ulcers.


There are several ways to help prevent mouth ulcers in cats:

Get annual veterinary dental exams. Cats should have a full oral exam and dental cleaning done by a vet every year. This allows early detection and treatment of any dental disease or issues that could lead to mouth ulcers.

Brush your cat’s teeth regularly. Daily brushing can greatly reduce plaque and tartar buildup, keeping your cat’s mouth healthy. Use a soft bristled toothbrush and cat-safe toothpaste.

Avoid trauma. Don’t use metal drinking bowls, watch for sharp toys and bones that could lacerate the mouth, and trim nails to prevent scratches to the tongue or gums.

Feed a high quality diet. Dry food helps mechanically scrape plaque off teeth. Wet food has moisture to promote oral health. Avoid hard treats that could cause damage. Prescription dental diets are also available.


The prognosis for cat mouth ulcers depends heavily on the underlying cause. According to PetMD, cancerous mouth ulcers have a significantly poorer prognosis.

However, in most cases mouth ulcers will resolve within 2-4 weeks with proper treatment, according to Non-cancerous mouth ulcers have a good prognosis if caught early and treated appropriately with medications prescribed by your veterinarian to speed healing and fight infection.

In cases of chronic conditions like stomatitis, ulcers may recur but can often be managed long-term with medications and dietary changes recommended by your vet. Regular checkups are important to monitor the condition.

Overall, the prognosis for feline mouth ulcers is generally good with prompt veterinary care. But malignant ulcers can be an exception, underscoring the importance of having any persisting mouth lesions checked out quickly.

When to See a Vet

Mouth ulcers in cats are typically not cause for major concern. Many resolve on their own within 1-2 weeks with some basic at-home care like soft foods, increased water intake, and cat-safe mouth rinses. However, it’s important to have your cat seen by a vet if the ulcers last longer than 2 weeks or are severe.

Signs that warrant a veterinary visit include:

  • Ulcers that persist longer than 2 weeks without improvement
  • Severe pain like crying out when eating
  • Bleeding from the ulcers
  • Loss of appetite or trouble eating
  • Significant weight loss

A vet can diagnose the underlying cause through a physical exam and diagnostic tests. Biopsies may be needed for accurate diagnosis. Once the cause is determined, the vet can provide an appropriate treatment plan which may include medications, dietary changes, mouth rinses, or addressing underlying illnesses.

It’s important not to delay seeing a vet if mouth ulcers are severe or persist longer than expected. Proper diagnosis and treatment from a vet can help manage ulcers and prevent complications.

Cured vs Managed

While mouth ulcers in cats can often clear up on their own, the underlying cause may still remain. This means the ulcers can frequently return if the root issue is not addressed.

Treatment therefore focuses more on managing the symptoms and discomfort of mouth ulcers in cats rather than curing the condition itself. Vets will aim to control pain, infection, and inflammation using medication. But once this treatment stops, the ulcers may come back.

According to PetMD, “The ulcers themselves are not the primary problem, they are a secondary effect of inflammation in the mouth.”1 So while the ulcers may resolve with treatment, the inflammation often persists unless the underlying disease or disorder causing it is cured.

In summary, while cat mouth ulcers can sometimes clear up on their own, the best chance of avoiding recurrence is to identify and treat the root cause of the inflammation if possible.

The Takeaway

In summary, cat mouth ulcers are typically caused by infection, trauma, or an underlying health condition. While some ulcers will heal on their own, most require veterinary treatment to control infection, reduce pain and inflammation, and address any underlying issues.

Treatment usually involves antibiotics, anti-inflammatory medication, pain relief, and topical medications. With prompt diagnosis and proper treatment, the prognosis for full recovery is good. Most cat mouth ulcers can be successfully cured or managed.

It’s important not to delay in getting veterinary care, as mouth ulcers can worsen and cause significant pain. Catching them early allows for more effective treatment. Cats may require soft foods during healing. With a veterinarian’s guidance, diligent at-home care, and follow-up visits, cat parents can support their pet’s comfort and recovery.

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