The Efficacy of Tinidazole in Naturally Occurring Periodontitis in Dogs: Bacteriological and Clinical Results

The efficacy of tinidazole in addition to a single course of scaling was studied in 14 dogs with periodontitis. Three test teeth, two with periodontitis and one with healthy periodontium, were selected per dog. Subgingival bacterial samples were taken, and clinical examination was carried out at each of four visits (0, 14, 90 and 180 days). The bacterial samples were cultured anaerobically using selective and nonselective media. All teeth in the dentition, except one diseased test tooth with periodontitis were scaled at the first visit and tinidazole or placebo administered twice a day for 7 days. The mean probing depth of the diseased test pockets was significantly more reduced in tinidazole+scaling (T1S1) than scaling alone (T0S1) group at all visits compared to baseline values. The most significant decreases of bacterial counts in T1 or T0 groups were found in agar corroding Gram-negative rods in both diseased and healthy T1S1 pockets and in slimy Gram-negative rods in diseased T1S0 pockets between visits 1 and 2. The intergroup comparisons showed that Gram-positive cocci decreased significantly more in S1 pockets as well as sporeforming Gram-positive rods in diseased S0 pockets of T1 than T0 group. The highest number of isolates was found in the group of pigmented Gram-negative anaerobe rods, mainly Porphyromonas spp. The percentage of Porphyromonas gingivalis-like isolates decreased to zero and Porphyromonas endodontalis-like isolates increased in all test teeth of T1 group at 14 days. It is concluded that tinidazole has good efficacy against P. gingivalis-like bacteria which seem to be periodontal pathogens in dogs.