Elevated levels of interleukin-1 (IL-1) have been shown to amplify the inflammatory response against periodontopathogenic bacteria. In humans, polymorphisms in the 𝐼𝐿1𝐴 and 𝐼𝐿1𝐵 genes are the most well-studied genetic polymorphisms associated with periodontal disease (PD). In contrast to human, there is a lack of knowledge on the genetic basis of canine PD. A case–control study was conducted in which a molecular analysis of dog 𝐼𝐿1𝐴 and 𝐼𝐿1𝐵 genes was performed. Of the eight genetic variants identified, seven in 𝐼𝐿1𝐴 gene and one in 𝐼𝐿1𝐵 gene, 𝐼𝐿1𝐴/1_g.388A>C and 𝐼𝐿1𝐴/1_g.521T>A showed statistically significant differences between groups (adjusted OR (95% CI): 0.15 (0.03–0.76), 𝑃 = 0.022; 5.76 (1.03–32.1), P = 0.046, respectively). It suggests that in the studied population the 𝐼𝐿1𝐴/1_g.388C allele is associated with a decreased PD risk, whereas the 𝐼𝐿1𝐴/1_g.521A allele can confer an increased risk. Additionally, the 𝐼𝐿1𝐴/2_g.515G>T variation resulted in a change of amino acid, i.e. glycine to valine. In silico analysis suggests that this change can alter protein structure and function, predicting it to be deleterious or damaging. This work suggests that 𝐼𝐿1 genetic variants may be important in PD susceptibility in canines.