Hi Everyone!
I promised to give an update. I apologize for the delay. Unfortunately I do not have a solution to report YET. To quickly sum up our experience over the last few months - it has consisted of 4 different vets, blood tests, allergy tests, yeast tests, and phenobarbital which hasn't caused any noticeable change. Roscoe is a year and a half now, and the licking and pacing is still considerable and every vet we have seen seems to be torn on whether this is behavioral or neurolgical. When they say "behavioral" it is not like we think... not a personality quirk or a voluntary action. It still indicates something is awry internally and chemically but is different than neurological misfirings.
That said, we had an excellent appointment today with Tufts Veterinary Hospital in MA. We finally feel that we are with a Dr. who has seen this before and who has a "plan." They are testing his liver (again) and looking for a possible shunt (as he is smaller than his siblings). If anything turns up, there could be a physiological aspect to this that hasn't been caught yet. If nothing, the doc wants to try Prozac for 4-6 weeks to treat this as a behavioral condition. If it is "behavioral", the Prozac should have an impact within 2-3 weeks or so.
I write this in hopes that someone else with the same issue may gain value or a leg up in their own journey. I will keep you posted and wish you all well.
Kate