What does the old military doctor mean?

The old military doctor has two meanings:

One is older and has been engaged in medical work in military units in the past or now. It means to appreciate. In the past, many excellent medical workers were concentrated in military hospitals because of strict military management and decent military style, and because of the high salaries of officers. People had a better view of military doctors and praised them as "old military doctors".

The other refers to social traveling doctors who pretend to be military doctors and treat diseases indiscriminately in society. If it's cured, you'll be ashamed to go to court. They seize the patient's psychology and achieve the purpose of cheating money. Here, we call some low-ranking and older doctors "old military doctors" in person, which is obviously ridiculous and will be called "old veterinarians" behind them.