Pointers are supposed to be narrow with a deep chest, a cinched waist and a tucked abdomen. They are NOT beefy dogs. You shouldn't be able to see their ribs but they're not meant to be anything other than thin. They are bred for speed and endurance. Pretty much any dog that's bred for speed is going to be thin. Pointing breeds, sighthounds, herding dogs that are bred to cover ground quickly, etc.