I suspect the vet is not aware that the dog is to travel by plane and the meds were dispensed for some other reason.

Pets should not be sedated for air travel.

The effect of changes in cabin pressure and altitude combined with the sedative can be fatal. The correct dosage to give the put is NONE. And most airlines would not knowingly allow the dog on the plane if they knew it had been tranquilized.

Your friend needs to get pup used to being in a travel crate by conditioning with treats to help him associate the crate with good things. If she doesn't think this is possible, that dog will be better off if he stays with a friend, or at a kennel while she travels.

I agree 100% with cynthia. Friend needs to train dog to be calm in crate. May try benadryl (diphenhydramine) to lightly calm the nerves, or a pheromone calming collar. Unfortunately some vets do still knowingly dispense sedatives for air travel.

Ditto what cynthia said.
Has your friend ever tried to travel on a plane with the dog? Maybe it's more her nerves than the dog's??
I've owned small dogs that had never been in a crate and had no problems carrying them on planes in a soft sided crate/carrier. The noise of an airport and the planes was always enough to keep them quiet.

I do hope she's planning on taking the dog on board with her. If not, then she should pay extra for counter-to-counter handling of the dog.
Never put it in cargo.

Great points, I am so not a dog person that I would never have thought of any of this, I am sure she is not sending him through the cargo section, he is small and would be with her in the cabin. Thanks all, I will pass this along to her.