The risk of the dog getting injured is the same going in and out of the truck as it is while hunting. One might argue that its even more so. The risk of injury from unnatural movement is higher. Ask your veterinarian. There's no argument to be made. The point is minimalizing risk anyway.
If my dog is an 84 year old grandma then hunting might seem like a poor decision to begin with anyways. Which would make the truck part a moot point. Muscle and stamina loss are real things that effect dogs and people too. Doesn't mean your dog can't do the job it loves to do. I would suggest to maximize the time with your dog as they don't live forever and you have been running out of time since the day you brought her home. I understand from your posts that Pheasant hunting is probably pretty low on the list of passions definitely after fishing but not after ice fishing. Some of us live for this and will do whatever we can to make our dogs lives as good as we can. (Not saying you are a bad owner or anything to the like)
The part about whether the dog is able to get in and out of the truck was advice given to me on this very forum last season. If the dog cannot do that anymore, she is not able to hunt. Stupid advice unless you look at your dog as a disposable tool and nothing more.
