Does anyone have experience flying with an anxiety-prone pet? My dog is small enough to travel in the cabin, but he hates being crated and has severe separation anxiety, so I’m afraid he won’t tolerate it well. Advice, please!

ETA: He is on anti-anxiety meds, but the vet doesn’t recommend sedatives for airplane flights. I’m mostly worried he won’t stay in the carrier - he hates being crated and he is soothed by being cuddled and petted, which I can’t do on a plane. Plus he won’t take treats when he’s anxious so a Kong usually isn’t helpful. (Yes, he’s impossible!)