Introduction

Feline Odontoclastic Resorptive Lesions (FORLs), more commonly referred to simply as tooth resorption, are one of the most common and agonizingly painful dental conditions seen in feline medicine. Studies indicate that up to 60% of cats over the age of six will develop at least one resorptive lesion. In this condition, specialized cells called odontoclasts—which are normally responsible for remodeling bone—malfunction and begin to aggressively attack and dissolve the healthy tooth structure. They eat away at the enamel and dentin, eventually exposing the highly sensitive inner pulp cavity and root canal to the open air and the mouth’s bacteria.

Feline Odontoclastic Resorptive Lesions

  • Common Signs and Behavioral Changes: Because the tooth’s sensitive nerve is exposed, FORLs cause excruciating, sharp pain comparable to that of a severe human cavity with an exposed nerve. Cats, however, are experts at hiding pain. You may notice subtle signs: suddenly dropping food while chewing, violently shaking their head, or chattering their jaw when trying to eat dry kibble. Some cats will swallow their food whole rather than chew it. You might also see excessive drooling, severe bad breath, weight loss, or the cat pawing frantically at their mouth. Visually, you may see a bright red dot of inflamed gum tissue actively growing over the hole in the tooth in an attempt to protect it.
  • Diagnosis and the Importance of X-Rays: A preliminary diagnosis is often made during a routine physical exam when the veterinarian observes characteristic red lesions along the gumline or notes the tooth ‘chattering’ reflex when a specific tooth is touched. However, a definitive diagnosis requires general anesthesia and full-mouth intraoral dental radiographs (X-rays). Because destructive odontoclasts often begin their work deep below the gumline on the tooth’s roots, a tooth may look perfectly healthy to the naked eye while the root is completely hollowed out and actively dissolving from within.
  • Treatment Protocol: Unlike human cavities, resorptive lesions cannot be filled, drilled, or saved; the cellular destruction is progressive and unstoppable. Because the affected teeth act as a constant source of severe, chronic pain, the only acceptable and humane treatment is the complete surgical extraction of the affected tooth and its remaining roots. Depending on the stage of the disease, the veterinarian will carefully amputate the crown or elevate out the remaining root fragments, suturing the gums closed to allow for rapid, pain-free healing.
  • Prognosis and Post-Surgical Care: The prognosis following surgical extraction is truly excellent. Most owners are astounded by the rapid improvement in their cat’s overall demeanor, playfulness, and appetite once the source of the agonizing chronic pain has been permanently removed. Because a cat that develops one FORL is highly predisposed to developing more in the future, meticulous home monitoring and strict annual or bi-annual professional dental cleanings with comprehensive X-rays are absolutely essential to catch future lesions before they cause significant suffering.

This blog is for informational purposes only and is not intended to provide diagnostic or treatment guidance. If you have any concerns about your pet’s health, please contact Cascade Heights Veterinary Center directly by phone at 206-403-1108,  email, or by scheduling an appointment.  Medications, supplements, and prescription diets can be conveniently ordered through our online pharmacy.