and whenever she heard a large word she said it over to herself many times, and so was able to keep it until there was a dogmatic gathering in the neighborhood, then she would get it off, and surprise and distress them all, from pocket-pup to mastiff, which rewarded her for all her trouble.
From A Dog's Tale by Mark Twain.
Is it safe to assume that dogmatic in this context has nothing to do with dogma? Also, does the word distress mean "impress" here?