The fourth premolar is the biggest tooth except for the canines....I read this (on many sites) "In dogs, the canine teeth, maxillary fourth premolars and mandibular first molars are clinically the most important teeth and root canal procedures are typically recommended as an option for treating these teeth as opposed to extraction when possible."
THIS site is very informative regarding extractions and makes me more certain I need to pre-qualify the dr who will do it (If necessary!) I just don't know if ANY will give me prices without a visit, though I would send her x-rays if my vet gives me them...
Taking the bite out of tooth extractions
It scares me that losing it will impact her and that extracting it could have complications. But who has $3k for a doggie root canal?