Originally Posted by
Mike Buckley
In the first image, I think you're trying to accomplish a nice image in an extraordinarily difficult setting. There is a bright light coming from the rear and side through the draperies. You are rightfully trying to balance it with a flash, though probably using a pop-up flash and at least a flash mounted to the top of your camera. Either situation will create the red eye. To top off the list of difficult situations, one dog is closer to you than the other one, which means one will be more brightly lit than the other one.
If it's possible to control the setting, arrange the dogs in an area where you can use natural, diffused light. That's because using flash effectively requires a lot of experience. I'm guessing from your images and comments that you understandably haven't taken the time to seriously study and master the use of flash.
You mentioned that the dogs' hair is darker than in the image. I'll explain why I doubt that's true: Imagine shining very bright, white lights such as studio lights on your dog. That's essentially what is happening when you're using flash. The difference is that studio lights would produce sustained light that would give you time to realize how their hair looks in that situation. Not only does the flash occur in a blip of time, it's being lit only when you're looking through the viewfinder. That doesn't give you enough time to appreciate how their hair appears under such bright light.
The reason at least one of the two dogs appears distorted when you photograph them together is for both a good reason and a bad reason. The good reason is that you have the smart sense to move in close to fill the frame with your subject. The bad reason is that when you get that close, you are forced to use a very short focal length. The result is a wide-angle focal length and all such lengths do indeed distort atleast at the edges in that situation. The solution is to photograph your dogs in an area that allows you to create a bit more distance between them and you. Fill the frame using anything other than a wide-angle focal length. If you have to use a wide-angle focal length, don't fill the dogs in the frame; leave unimportant space around them that you can crop out of the image during postprocessing.
Hope this helps!