My 5-year-old schnauzer developed a swollen gum just above his upper fang. It appeared overnight. It just a tiny part of the gum (1cms x 1cms) that is red and swollen and it lost the dark normal gum color the rest of the mouth has.
I took him to the vet, he suspected it was traumatic since it appeared overnight and prescribed anti-inflamatory (Rimadyl) for 2 days. It didn't work. He then prescribed Papenzym for 5 days. It didn't work either. The lesion still the same size, color and location. It has not grown, it does not hurts the dog, even when pressed hard, the tooth if firm and healthy, it does not bleed, it doesnt bother the dog to bark, eat, drink water or play.
Vet insists it's not a neoplasic lesion, since it clearly seems like the gum tissue swollen, so cutting to extract a sample for a biopsy would damage the gum more. He doesn't considered to do an x-ray since the tooth is firm, healthy and it does not have pain. He checked under the gum above the teeth for foreign bodies and nothing.
His best guess is that it was a traumatic lesion, something he ate or a hit that swollen the gum, then it keeps on swollen because the lower fang keeps pressing the site.
Thing is, that he is puzzled too because of the lesion, he will investigate on local anti-inflamatories to use or perhaps injecting cortioids right on the lesion to reduce swolleness and revert the cycle where the lower fangs keeps bruising the lesion.
I'd like to get some other people's opinion in order to expand the options of the causes and treatment of the lesions.