Periodontal disease is known to be the most common and serious health problem in dogs today. Despite the rather large arsenal of medicinal substances, the problem of treatment and prevention of periodontal disease remains relevant. Based on this, the purpose of the work was to study the features of chronic catarrhal gingivitis and to develop an effective treatment regimen for dentistically ill dogs. For research, two groups of animals with chronic catarrhal gingivitis were formed in 5 dogs in each (control and experimental), selected on the principle of analogues in terms of age, character and localization of the inflammatory process. Animals of the control and experimental groups were performed tartar removal, irrigation of the oral cavity with water and drying of the mucosa with a sterile gauze swab. Dogs of the control group on the mucous membrane was applied 1 ml of septogel 2 times a day, and the experimental – argumentistin 2 times a day. Before and after the procedures on the mucous membrane was applied a 3 % solution of hydrogen peroxide. It was determined the prevalence of dental disease in dogs, the influence of microflora on the condition of the oral cavity of dogs with chronic catarrhal gingivitis, the clinical condition and the main indices and samples were studied, reflecting the intensity of the inflammatory process in the gums of sick dogs and was developed a method of treatment. The results of researches have shown that the use of argumentistin in the complex treatment of dogs with chronic catarrhal gingivitis helps to reduce the recovery period by 5 days.