Once you read enough program descriptions on VIRMP, you start to get a feel for who might give a potato about their interns and who might not. I looked for things like mentions of guaranteed days off during the week, how much PTO they give and when you can use it, what overnight ER support looks like, etc.
When I reached out to current interns, I also asked them about these things and what their experiences were with them. I also asked questions like how they would describe their quality of life (with, of course, the expectation that this is a rotating internship program and you are going to be quite busy with it regardless of what program you end up in), how they would describe the quality of mentorship they have received, what their experience is with support (or lack thereof) on ER overnights, etc.
You also just hear things through the grapevine. When you get on clinics, asking house officers about where they applied, whether they know anybody at the places you are looking at, etc is another good way to get some insight.
It’s a good idea to talk with your faculty clinicians about this stuff as well. As I’m sure you have experienced by now, vet med is a small world - people know people all over the place.
When you start interviewing for programs (if they do interviews, not all of them do), you can also use this as another opportunity to get a feel for the vibe of the program and aspects you are especially interested in/that are important to you. Remember that you do not have to rank all of the programs you applied for.
I also want to note that different specialties feel differently about whether you do a private rotating internship or an academic rotating internship. Some have strong feelings about this, some don’t. General advice for the masses who may be interested in specializing: talk to a faculty clinician in your specialty of interest about this when you are thinking about where to apply.