Hi, sorry, I got no solutions for the scooting, but was talking to my vet about Poppy's anal glands a few weeks ago. She has to have them emptied every couple of months. She doesn't scoot but licks and licks when they need doing. I asked the vet why they kept filling up because I thought dogs mostly got them through not having enough roughage in their diet, but Poppy has loads. He said it was very common for labs to have this problem because they often have a layer of fat around the anus that stops the glands from being stimulated by the feaces and emptying themselves. The dogs themselves can be slim, but still have this ring of fat there.
Rosie
ps I know you can empty them yourself and the vet explained and showed me what to do. Next time they needed doing I armed myself with rubber gloves and had a go. I felt the glands ok and started to squeeze in the downward motion the vet described but nothing happened and I lost my bottle. I leave it to the vet now!