Background: Feline chronic gingivostomatitis (FCGS) is a challenging disease with unclear causes and limited treatment options. The most effective treatment for FCGS is tooth extraction. However, most cats require additional drug treatment for refractory FCGS even after undergoing extractions. We hypothesized that the combination of interferon-ω (IFN) and cyclosporine (CsA) would improve clinical outcomes. This study aimed to evaluate the long-term efficacy of IFN and CsA in FCGS using Stomatitis Disease Activity Index (SDAI) scores. In this study, the treatment process was divided into two stages: in the surgical stage (Stage 1), all cats underwent tooth extraction combined with submucosal IFN injection; in the immunomodulatory stage (Stage 2), additional IFN/CsA treatment was administered to cats with refractory FCGS. Results: The therapeutic response was monitored during treatment period using SDAI scores. The patients were classified into four groups by oral examination: Group A (Surgical remission), Group B (Substantial improvement to resolution), Group C (Partial improvement), and Group D (No response). Patients achieving complete remission following surgical treatment were classified into Group A (39.2% of all cases). Patients assessed as having refractory FCGS after surgical treatment accounted for 60.8% of all patients and were divided into three groups. Groups B, C, and D accounted for 52.1%, 45.2%, and 2.7% of refractory cases, respectively. In addition, the SDAI scores showed significant differences across groups at all time points. Receiver operating characteristic curve analyses identified key SDAI thresholds for early classification: a T ₁ score cutoff of 6.5 and a T ₀ –T ₁ score change cutoff of − 14.5 effectively distinguished Group A. The long-term follow-up revealed that cats classified as “subs-resolution” at T ₆ were significantly more likely to sustain clinical improvement for ≥ 2 years than those in the “non-partial” group. Conclusion: This study showed that the combination of IFN and CsA is an effective therapeutic option for refractory FCGS, with more than half of treated cats showing clinical improvement and 76.5% of those achieving subs–resolution at 6 months maintaining remission for 2–6 years. These findings further indicate that evaluating SDAI scores six months after a three-month course of immunomodulatory therapy provides prognostic value for predicting long-term outcomes.

Gingival recession from traumatic occlusal contact commonly affects feline mandibular premolars and molars. Although crown reduction is routinely performed to eliminate traumatic occlusal forces, its ability to restore established periodontal defects remains unclear. This study evaluated whether adjunctive periodontal surgery provides additional clinical benefits following crown reduction. This retrospective study included 17 cats (34 teeth) with malocclusion-associated gingival recession. Treatment grouping was performed at the tooth level, with one cat contributing teeth to both the Control and Group A. Teeth were classified into three groups: no treatment (Control), crown reduction alone (Group A), and crown reduction with adjunctive periodontal surgery (Group B). Gingival recession, clinical attachment level (CAL), root coverage, and the vertical bone defect ratio (VBDR) were evaluated before and after treatment. Between-group differences were analyzed using linear mixed-effects models. Control showed no significant changes. Both treatment groups showed significant improvements in gingival recession, CAL, and VBDR. Compared with crown reduction alone, adjunctive surgery yielded significantly greater CAL improvement, radiographic bone healing, and overall clinical success rate (91.7% in Group B vs. 25.0% in Group A), though root coverage did not differ significantly. Traumatic occlusion elimination is foundational for managing feline malocclusion-associated gingival recession. However, adjunctive periodontal surgery enhances periodontal recovery and overall success, offering a valuable tooth-preserving option when complete reconstruction is required.