Abstract
The aim of this study was to compare the healing of periodontal pockets treated with curettage following systemic administration of doxycycline or amoxicillin-clavulanate.

A total of 24 periodontal pockets in 10 clinical canine patients (8–12 kg) were evaluated regardless of sex or age. Inclusion criteria were good cooperation of both patient and owner. In each dog, periodontitis stage PD 2–3 was radiographically diagnosed on one canine tooth (104/204/304/404). The depth of the periodontal pocket was measured, and the deepest value and its location were recorded. All patients underwent standard periodontal treatment including closed subgingival root planing and curettage (RP/C) using a Gracey 7/8 curette. Dogs were randomly divided into two groups of five (12 pockets per group). Both groups received antibiotics for 7 days post-treatment. Group 1 received doxycycline (10 mg/kg once daily p.o.), Group 2 amoxicillin-clavulanate (20 mg/kg twice daily p.o.). Thirty days after treatment, follow-up examinations and repeated measurements were performed at the same sites. Statistical analysis showed significant improvement within both groups: paired t-test Group 1 (doxycycline), α = 0.000119; Group 2 (amoxicillin-clavulanate), α = 0.00145. The Mann-Whitney U test revealed no significant difference between groups before treatment (p = 0.44; mean depth 4.08 mm in Group 1 vs. 4.0 mm in Group 2). However, a significant difference was observed 4 weeks after therapy (p < 0.05): mean pocket depth 1.66 mm in Group 1 vs. 2.58 mm in Group 2.

Conclusion
Systemic doxycycline administration significantly enhances healing of periodontal pockets in dogs compared with amoxicillin-clavulanate. The study was conducted as part of student training at the University of Veterinary Sciences Brno.