Hi, I'm new here! Just thought I'd mention that my not-so-little girl Rosie is 11kg - just over 24lb - and has no fat on her, when she did drop below that weight the vet told me she was verging on underweight. She's 10 years old. So dependent on the size (height) of the dog!
Some lovely pics on here Off to the 'golden oldies' section now to post a pic of my girl!