Animals respond to fear with fight, flight, or freeze. I was recently working with a dog who would flight or freeze when approaching an open car door. Her owner would pick her up to put her in the car. Her level of fear was around 6 out of 10. She wasn’t chaotic, but it was enough that there was no way she would get in the car on her own. Exercising beforehand and putting a high-value treat in the back seat didn’t make a difference. When lifted and placed in the car she would be stuck in fear mode. In the past she had thrown up in the car.
Dogs can have fears that seem irrational and unaddressable. There are things they get stuck on and it's helpful to remember their brains need a little more time to process.
I block the flight response by putting her leash on and thread it through the back seat so I could lean in from the opposite car door. She has all the time she needs, but I will not allow her to go backwards. I keep my hold on the leash steady. If she leans back and the cinch collars puts pressure on her neck, it’s her own energy creating that. If she moves forward I take up the slack and be still. I smile, breathe, don't lock into eye contact, and don’t say much.
It took maybe 8 minutes but she climbed into the back seat. That's when I give her praise, a treat that she likes the smell, and a moment to relax. We get out of the car and end there. The next time it took about 4 minutes, and a couple days later she was going in the car without me. You have to tell yourself it could take 10+ minutes of just standing there waiting for the dog's fear to go down. But that's the important insight. You want the dog's brain to figure it out and move through the obstacle. It's not helping the dog overcome fear if you override the body by picking the dog up or pull hard on the leash.
If her fear had been closer to 9 out of 10, a first step might have been to just have a moment of calmness next to the open car door, maybe two paws over the threshold, and end the first session on that.
It's a big deal to dogs when you show them you can sit there and wait for their mind to reach a calm state. Patience builds trust and respect. It makes all the difference to be able to pause, but not move backwards, for how ever long you need.