Heliobactor is a bacteria, not a virus-It is the Genus name that contains (I believe) 35 or so strains. The most common is H. Pylori. I have not looked into it in years, so please google and don’t take my word for 100 percent accuracy. I do recall reading back then that there was a potential for it to be contagious-though I do not recall all the details.
I think what you are calling Lymphocyctic Gastritis, is actually Lymphocytic-plasmacytic enteritis(LP), and is the most common form of IBD in dogs. “They” do not know for sure what the cause of this is, but its believed that it is an immune response set off in response to environmental allergies, diet etc.
Google Lymphocytic-Plasmacytic enteritis for lots of info.
