**5. Conclusions**

In conclusion, CGC affects female and male dogs in relatively equal proportions, with a mean age of nine years, and the highest frequency in Staffordshire bull terriers. The most common CGC histological subtype was the undifferentiated carcinoma. CGCs were associated with increased chronic inflammation parameters and with a greater chronic inflammatory score when *Helicobacter* spp. were present. Understanding the altered molecular pathways associated with gastric carcinoma development including its histological subtype remains a challenge. The significance of the findings from the cell cycle regulators and cell adhesion molecules in the subtypes examined, should be combined with clinicopathological data and additional molecular analysis to further understand the molecular mechanisms and similarities between dogs and humans.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/ani11051409/s1, Table S1: 149 cases of canine gastric carcinoma by sex and breed frequency.

**Author Contributions:** Conceptualization, S.L.P., A.S.-B. and A.H.; methodology, S.L.P., A.S.-B. and A.H.; investigation, A.H. and W.E.B.; resources, S.B. and G.A.R.; data curation, A.H. and W.E.B.; writing—original draft preparation, A.H.; writing—review and editing, A.H., S.L.P. and A.S.-B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study is contained within the manuscript and Supplementary Table S1.

**Conflicts of Interest:** The authors declare no conflict of interest.
