Infected gums may be painful, impede eating, and infect or poison the body. Here are some rules-of-thumb for this fairly common condition. Interestingly it most prevalent in the cats around here, and they often need treatment.
Bleeding gums with loose teeth: Homeopathic Arsen Alb.
Inflamed red gums, with bleeding and a stench: Kreosote.
Ulcers, stench, great sensitivity, flabby tongue with indentations: Merc sol.