I have to have a way to have my dog sedated for about 5 hours?

I find exercise before is the best thing. I have two JRT's and you know they are hyper. I don't use a crate they are seat belted in the back seat. One is a champion racer three years in a row and after the trials he sleeps all the way home, His sister doesn't compete but also sleeps all the way home occasionally getting up to see where we are.

With anxiety you should start long before your trip, taking him on short rides in the car gradually increasing the time spent in the car and treat him when he does well. For safety he should be seat belted in. Do not feed him right before make sure he has eaten a couple hours before and relieved himself. Make frequent stops carry water and water him at the stops and let him relieve himself and again treat him in the car when he does well just a small treat.

Is he crate trained? We put our bull terrier in a crate every time he goes somewhere, did it with the last dog too. Try Rescue Remedy, available in Pet stores or a Health food store. It works.

Before you go take him on a good run, and then does him with benedryl as if he were a baby. That should knock him out. If not you want to know before you are in the car with him.

A crate for the car is a good idea too.

your vet doesn't want to sedate him because dogs don't handle light sedatives well - their behavior is unpredictable. A light sedative or benedryl could make him MORE hyper.

Never give a dog of any size medicine without first consulting your vet.
Instead of having a free dog in the car place him in a crate or carrier, some dog feel a bit more secure if in a carrier.

Ask at an herbal petstore..melatonin and benedryl, rescue remedy plus EXERCISE him before leaving. I trot my over active German Pinsched next to my bike for 30-45 mins before I leave.

Don't sedate him. He will get tired and eventually calm down. And, you can make several stops.