Understanding Pyogenic Granulomas in Cats

15 Aug Understanding Pyogenic Granulomas in Cats

What Is A Pyogenic Granuloma?

Cats sometimes present with an unusual oral lesion at the lower jaw. These lesions are characterized by a solitary raised site of red gingiva and mucosa, usually located adjacent to the lower 1st molar.

The term “pyogenic granuloma” is the most common term for these lesions. The name is a misnomer, however, as these are not granulomatous lesions and do not have a bacterial component. These lesions are actually angiomatous rather than granulomatous.

Superficially, they may closely resemble a squamous cell carcinoma; however, biopsy rules out cancer. Instead, histopathology shows an inflammatory pattern on a spectrum ranging from lymphocytic-plasmacytic inflammation in the early stages to a fibrovascular hyperplastic mucositis for more chronic lesions. Because a distinct histopathologic pattern is not always present, definitive diagnosis should be based on both histological and clinical appearance. Differential diagnoses include squamous cell carcinoma, peripheral ontogenic fibroma, osteosarcoma, amelanotic melanoma, lymphocytic plasmacytic stomatitis, or a focal foreign body.

 

What Do Pyogenic Granulomas Look Like?

Upon physical exam, these focal lesions are red, raised, ulcerated, friable, lobulated, and easily hemorrhagic. In most cases, the condition is unilateral, i.e. on one side of the mouth only. However, in about ⅓ of affected cats, these lesions are present bilaterally, located at the same site on opposite sides of the jaw. Many affected cats show difficulty eating. Abnormal chewing motions are frequently described. Occasionally pawing at the mouth or weight loss are noted. A foul odor from the mouth is sometimes present from secondary bacterial involvement

 

How They Form

Pyogenic granulomas are an inflammatory sequela to traumatic tooth contact. The most common sites for these traumatic lesions to form are at the extraction sites of the lower 1st molars. Specifically, the lesions form immediately adjacent to the extraction site at the buccal alveolar mucosa.

After extraction, the local anatomy is altered. Even with just a small change in anatomy, an unintended side-effect could be direct contact with the opposing sharp cusp of the upper 4th premolar. This initial tissue contact can result in local inflammation with associated tissue swelling. This in turn leads to even more contact with the upper 4th premolar, and the contact trauma persists or progresses.

Although extraction is often the precursor to these lesions, they can also develop in patients with no history of oral surgery. One possible reason could be an anatomical predisposition, like a cat with an overly wide mandible, or a narrow maxilla, or perhaps a jaw length discrepancy. An otherwise innocent action could serve as an inciting event, like a sudden snapping jaw closure (like what happens when the chin is hit). This could force the sharp cusps of the upper teeth into contact with opposing lower jaw mucosa. All it takes is a little initial contact irritation, which swells the mucosa slightly, and the contact trauma will persist and perhaps progress.

 

How To Treat a Pyogenic Granuloma

For milder conditions, conservative treatment may be attempted. This could be a combination of analgesics, anti-inflammatories, antibiotics, topical medication (e.g. Oratene enzymatic gel), and softened diet. If conservative management doesn’t provide definitive resolution, then interceptive treatment will be needed. In many cases, by the time affected cats show outward signs of pathology, these contact lesions have often progressed to very swollen painful conditions.

Veterinary clinicians often address these lesions though oral surgery – by excising the lesions, with the intent to remove a source of pain as well as collect a biopsy simultaneously to confirm diagnosis. However, unless the actual source of the problem is managed concurrently, the lesions recur quickly. To address the tooth contact trauma, either odontoplasty or extraction will be needed.

 

 

 

 

 

For minor lesions, odontoplasty (“adjustment”) of the offending tooth might work. The sharp cusp can be conservatively smoothed, to remove the very sharp point. Odontoplasty can be performed with sequential water-cooled polishing disks, white stones, or very cautious application of a highspeed diamond bur. Care is taken to avoid excessive removal of tooth structure and prevent exposure of the pulp tissue. A sealant is applied concurrently.

However, for more serious lesions or for chronic lesions, extraction of the offending tooth should be performed. This provides the most predictable outcome. Whether to smooth down the cusps or extract the teeth is a judgement call, based on the severity of lesions, the pet owner’s expectations, etc.

 

 

 

 

Prevention

In the author’s practice, odontoplasty of the upper 4th premolar is performed prophylactically whenever extraction of the lower 1st molar is performed. Odontoplasty is a physical “adjustment” of a tooth shape, height, or sharpness.

For pyogenic granuloma prevention, the sharp cusp of the upper  4th premolar is blunted to create a smoother rounded cusp. This approach dramatically reduces the chances of post-extraction pyogenic granuloma formation. Odontoplasty with concurrent sealant application is a relatively quick procedure. The minimal additional anesthesia time and the material cost invested are easily outweighed by the benefits to patient and pet owner.

 

Cat Dentist in Denver, Colorado

If your cat is experiencing dental issues or is due for a checkup, please don’t hesitate to contact us to schedule an appointment.

 

References

Clinicopathologic characterization of oral pyogenic granuloma in 8 cats

J Vet Dent. 2014 Summer;31(2):80-6. 

 

Caudal mucogingival lesions secondary to traumatic dental occlusion in 27 cats: macroscopic and microscopic description, treatment and follow-up.

J Feline Med Surg. 2015 Apr;17(4):318-28. 

 

Donald Beebe, DVM, Dipl AVDC 

© Donald Beebe, DVM

 

 

Images used under creative commons license – commercial use (8/15/2024). Photo by Jelena Senicic on Unsplash