You can enter pharmacy school without completing a 4-year degree:
https://blog.neomed.edu/no-bachelors...-prerequisites
I think you can get into MD and DDS with 3 years completed as a minimum requirement, but it's super-rare.
There are also some 6-year BS/MD combined degrees in the US, kind of like the MBBS degree.
The main distinction between masters and professional doctorates seems to be the following:
1. Master's degrees generally take 1 or 2 years; professional doctor's degrees take 3 or 4 years
2. The professional doctor's degree is an entry-to-practice degrees for everyone entering the profession.
Some professional fields - like education, social work and engineering - follow the bachelor's/master's/doctorate hierarchy. There' not one common degree required by all.