Tooth Resorption in Cats: The Lesion Only X-Rays Show

Tooth resorption starts below the gum line, where no toothbrush, no mouthwash, and no amount of scaling can reach it. By the time a defect is visible at the gingival margin, 30% to 50% of that root may already be gone. Radiographs find roughly 2 to 3 times more lesions than a conscious oral exam, which is why a cat that keeps dropping food needs films, not another dental cleaning.

The lesion begins under the gum line

Odontoclasts, the same cells that resorb deciduous teeth, attack the cementoenamel junction and work inward through cementum, then dentin, then pulp. The process is usually symmetric and favors the mandibular third premolars, teeth 307 and 407, followed by the molars. A pink or red tuft of tissue at the gum line, a tooth that looks cut off at the base, or a hard sharp edge that catches a probe are the three findings a clinician can see without film.

Signs owners miss at the bowl

Cats do not stop eating; they change how they eat. Watch for chewing on one side, dropping kibble after 2 to 3 chews, jaw chattering, tongue flicking, head tilt while eating, taking 3 times as long over a meal, and preferring soft food. Drooling and bad breath appear later. Roughly 30% to 50% of affected cats show no obvious sign at all, which is why the condition is found on routine films in cats that seem fine.

Why it gets called gingivitis

Gingivitis is inflammation of the gum that reverses with cleaning, and it looks red, swollen, and bleeds. Resorption is structural loss of tooth, and scaling a resorbing tooth exposes dentin and hurts. A cat that had a scaling 12 months ago and is dropping food again did not fail to heal; the lesion was never on the treatment list. The same error shows up as a cat labelled a fussy eater at 9 years old, when the real finding is 4 resorbing premolars.

Type 1, type 2, type 3: what the film decides

Type 1 shows a radiolucent defect with a visible root canal and often concurrent periodontitis, so the whole root must come out. Type 2 shows a root replaced by bone, with no periodontal ligament space and a ghost outline, so crown amputation with intentional root retention is the safer surgery. Type 3 is a mix in the same tooth. Without films, a surgeon cannot tell which is which, and a type 2 root that is forced often fractures and leaves a sequestrum.

The pre-anesthetic numbers that matter after 10

Full-mouth films need general anesthesia, so the workup runs first: packed cell volume, creatinine, total T4, and systolic blood pressure. A systolic reading above 160 mmHg on 3 separate measurements means treat and recheck before anesthesia, because hypertension raises bleeding risk. T4 above 4.0 µg/dL in a cat over 10 changes the anesthetic protocol and the healing timeline. Blood pressure technique matters more than the machine, and the cuff site and repeat protocol decide the number.

Extraction day, hour by hour

Expect 20 to 40 minutes of surgical time for 4 to 6 teeth, plus 10 to 15 minutes of films, with recovery in the clinic for 2 to 4 hours. Buprenorphine at 0.01 to 0.02 mg/kg every 8 to 12 hours, or meloxicam as a single 0.1 mg/kg dose then 0.05 mg/kg, covers the first 3 to 5 days. Gabapentin, 5 to 10 mg/kg every 8 to 12 hours, helps a cat that will not eat through the soreness.

The 6-week eating ladder

Day 0 is water only for 2 to 4 hours, then a pate or blended diet at room temperature. Days 1 to 3 stay on soft food in 3 or 4 small servings, with no kibble if sutures are placed. Days 4 to 7 offer soft food plus softened kibble soaked 10 minutes in warm water. Week 2 adds normal kibble if the cat chews comfortably. Week 6 is the point where gum tissue has closed over the extraction sites. Call the clinic if the cat refuses food for 24 hours, bleeds for more than 5 minutes, or paws at the mouth.

What actually slows the next lesion

Nothing reverses resorption, and no diet prevents it. Daily brushing with a soft brush and pet toothpaste, plus a dental diet carrying the VOHC seal, reduces plaque and gingivitis, which is a different disease. Films every 12 months after age 5 catch lesions at 1 to 2 mm instead of 5 mm, when the surgery is smaller and the cat is younger. The blood pressure protocol belongs in the same pre-op folder, and the age calculator explains why a 12-year-old cat is a 64-year-old patient for anesthetic purposes. Blind cats adapt to a lost field of vision the way these cats adapt to a lost tooth, quietly, until function is gone.

Stage	Food texture	Pain control	Normal at this point	Call the vet if
Day 0, first 4 hours	Water only, then 5 mL pate	Opioid given in clinic	Sleepy, drool under 2 mL	Bleeding over 5 minutes
Days 1 to 3	Pate, 3 to 4 meals	Buprenorphine every 8 to 12 hours	Eating 50% to 75% of normal	No food for 24 hours
Days 4 to 7	Soft food plus kibble soaked 10 minutes	Meloxicam or gabapentin, tapering	Chewing both sides, 1 site tender	Swelling or pus at a site
Week 2	Normal kibble if comfortable, 4 meals	None in most cats	Weight within 100 g of baseline	Dropping food again
Week 6	Normal diet, 2 meals	None	Gum closed, pockets under 1 mm	Bad breath returning

What the bill looks like

Full-mouth radiographs run USD 100 to 250, anesthesia USD 150 to 400, and extraction USD 60 to 200 per tooth. Four to six teeth usually total USD 700 to 1500; a full-mouth extraction lands between USD 1200 and 2500. Doing films only when a tooth looks bad costs less once and more later, because type 2 roots are missed and re-treated.

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