1. The right time to call the on-call surgeon is highly surgeon-dependent.
Dr. Fox wants to be called when the dog is 15 minutes from being in the OR, fully cleared for surgery, deposit paid, anesthetized, and not a moment before. He has no time for your "so...I might have a back dog" bullshit. He only cares if he needs to put on his scrub pants in the next half an hour.
Dr. Roman wants to be called when you miiiight have a septic abdomen. Then he wants to be called when the dog is an hour from being in the OR.
Do not mix this up.
2. "On call" is a flexible term:
Got a surgery? Call the on-call surgeon. Sometimes this person is an ER doctor who is comfortable performing emergency surgery.
Unless it's a back dog, a septic abdomen, or an open chest. Then you have to call the actual surgeon, who is whichever surgeon was scheduled in the OR that day.
Unless the third year resident is on call. That guy can cut whatever.
I'm not sure what you do if the on call spot is blank on the schedule. That's fun.
3. "On call" is a flexible term, redux:
You can call the exotics specialist, the criticalists, the surgeons, and sometimes the ophthalmologist in the middle of the night. The neurologist wants you to call the criticalist instead.
The criticalist wants you to call the ECC resident. Unless the first year resident is on call, then she wants you to call the resident first (so she gets the experience of being called at 3 am) and then her. Unless it's really busy, in which case you can just call her. Or if it's about one of her cases. Or you can call the third year resident who is essentially always on call anyway.
YAAAAY!