What its position is on banning the (a) third-party sale of dogs and (b) sale of dogs under eight weeks-old.

The Scottish Government has no current plans to ban the third-party sale of dogs. The Pet Animals Act 1951 requires that those selling animals as pets in most circumstances, including from a private dwelling, operate under a license issued by a local authority. We are committed, by the Programme for Government 2017-18, to improving the licensing for dog, cat and rabbit breeding, dealing and selling.
The commercial third-party sale of dogs aged 8-12 weeks without a licence and the sale of dogs under 8 weeks of age is effectively prohibited by the restrictions in the Licensing of Animal Dealers (Young Cats and Young Dogs) (Scotland) Regulations 2009 and the Breeding and Sale of Dogs (Welfare) Act 1991 which both require that an animal is kept with its mother until at least 8 weeks of age.