This explains my problem:

Dog Farts (Part 1): Problems That May Be Causing Your Dog To Pass Gas

All mammals produce intestinal gas, and dogs are no exception. Compared to cows, which produce upward of 60 quarts of gas a day, dogs are relatively modest in their output. What they lack in quantity, however, they make up for in pungency – their gas is unusually smelly. Even a small dog can clear a large room, and bigger dogs, especially those who are real food-hounds, can be downright unpleasant to be around. Part of the reason we notice dogs’ gas so much is that dogs haven’t been taught to hold it in. They don’t go out of the room to pass it.

The intestinal tract is filled with bacteria that help process foods and aid in digestion. As part of their natural metabolism, the bacteria release clouds of sulfurous gases, which gives intestinal gas its unpleasant smell. The more protein there is in the diet, the stronger the smell.

Cows and other herbivores produce a lot of gas, but there isn’t enough meat-based protein in their diets to create large amounts of sulfur gases. Dogs, on the other hand, eat a lot of protein – quite a bit more than most people. They don’t necessarily have a lot of gas, but when they do, it’s powerful stuff.

It’s not only protein that contributes to high-octane gas – it’s also the type of protein. Many commercial dog foods get their protein from animal by-products; feathers, for example, or ground-up bone. These ingredients are harder for dogs to digest than protein that comes from “whole” foods, such as chicken meat or eggs. The harder the body has to work to process protein, the more flatulent a dog is going to be.

A surprising number of dogs are sensitive to ingredients in their food. For example, milk is a
common ingredient in dog food, but many dogs have a condition that makes it difficult for them to digest it. This condition, called lactose intolerance, can make dogs extremely gassy.

Food allergies are another problem. Dogs who are allergic to ingredients such as soy or wheat aren’t able to digest their food efficiently and tend to be gassy. They often get diarrhea as well.

One way to tell if your dog is sensitive to something in his diet is to write down every single thing he’s had to eat within the 24 hours preceding the gassy episodes. Sometimes something as simple as switching to a different brand of treats will make intestinal gas a little less unpleasant. Your veterinarian may recommend putting your dog on a diet called an elimination diet. He’ll be given a hypoallergenic food containing ingredients he’s never had before. If the gas goes away, you’ll know that something in his food was causing it.

One of the three people who regularly read my blog, Dr. Mommy, just reminded me of a classic article in Endo by Bender and Seltzer:

Authors: Seltzer S, Bender IB.
Title: Cognitive dissonance in endodontics.
Journal: Oral Surg Oral Med Oral Pathol
Date: Oct 1965
Citation: 20(4):505-16

Purpose/Objectives: To determine if cognitive dissonance is present in endodontics

Discussion: Cognitive dissonance is the existence of views, attitudes, or beliefs which are inconsistent or incompatible with one another but, nonetheless are held simultaneously by the same person. It is believed that if the three basic principles, the endodontic triad, are followed faithfully treatment must be successful. These principles are; a) thorough debridement of the root canal, b) sterilization of the root canal, and c) complete obturation of the root canal. Dissonance begins to occur when the principles are followed and failure results or through intention or neglect the formula is not followed and success results. One of the examples cited was the technique of culturing canals. Many false negative cultures exist yet many endodontists state, a poor evaluation tool is better than no evaluation tool at all. Any success obtained from treatment in the positive canals cultured is ascribed to a significant reduction in the number of microorganisms and removal of most of the inflamed or necrotic tissue. Complete obturation should yield a good result, assuming the root canal is well debrided and sterilized. Again cognitive dissonance occurs when inadequately obturated canals are evaluated as being successful. The hollow tube theory, proposed by Rickart and Dixon in 1931 has been cited as definite evidence that complete obturation of the root canal is essential for periapical repair. As long as this is accepted as evidence there is no dissonance. However, doubts increase when in routine full mouth radiographs teeth with partially filled root canals and complete absence of PA pathosis exist. How these areas regress and disappear if the canals are not filled does not follow the triad. How can failures be explained rationally when we have faithfully followed an acceptable formula for success? Is success based on radiographic criteria, clinically asymptomatic patients, or histological evaluation?

Conclusions: In spite of faithful adherence to a basic principle a failure can still result. The endodontic triad has some dissonance inherently. To obtain the questions that remain unanswered more research is needed and re-evaluations of previously accepted facts are in order. One must be willing to stop ignoring the dissonance and admit that treatments sometimes fail, for there can be no attempt, at solution, of a nonexistent problem.