The main culprits behind a dog's red gums and bad breath are the overgrowth of harmful bacteria in the mouth or gut. When there's an excessive presence of these harmful bacteria in a dog's gut microbiome, the foul odor they produce can eventually enter the bloodstream, leading to bad breath in the dog.

The gut microbiome residing in a dog's digestive tract and the oral microbiome in its mouth are closely interconnected. Oral health issues such as gum inflammation, cavities, and bad breath can induce excessive inflammation, affecting not only the dog's mouth but also its overall health. It's important to maintain clean oral hygiene in dogs to manage their oral microbiome. Additionally, certain ingredients in a dog's food or treats can negatively impact its digestive system, leading to an imbalance in the microbiome and causing bad breath. Supplementing with missing nutrients through nutritional analysis can help increase microbial diversity in the gut microbiome.