
One of our Bassets had this surgery, done by my regular vet out in Canada. I have to say it's NOT a surgery I'd have done if there is any alternative. He was okay, but it was a nasty surgery in terms of having to keep his stools soft for some time. We got pretty close to needing this done, with another hound who had repeated bouts of AG inpaction and infection. Repeated flushing and packing didn't achieve a result, so the next step was to have them removed. Thankfully at the last moment, he seemed to improve, and the surgery was avoided.
I would have thought any good vet would be able to do this surgery without the need for a specialist?
I still urge you to try to resolve this by topical treatment (oral tablets, antibiotics, rarely work). And look to diet - never mind using All Bran, if you can get his stools firmed up, the glands should work correctly. But the treating vet should know whether surgery is now the only option.