Let's see some pictures of her! Welcome to the forum.
Like humans, swimming just isn't for some dogs. I wouldn't force the issue, you will end up causing her to develop a fear. Most dogs will swim instinctively if they are forced to do so but will only swim for pleasure if they enjoy it. I wouldn't push it, at 9 years old, had she wanted to swim regularly she would have started by now.
In relation to the itch, what food is she on? Do you know what she is allergic to?
Like humans, swimming just isn't for some dogs. I wouldn't force the issue, you will end up causing her to develop a fear. Most dogs will swim instinctively if they are forced to do so but will only swim for pleasure if they enjoy it. I wouldn't push it, at 9 years old, had she wanted to swim regularly she would have started by now.
In relation to the itch, what food is she on? Do you know what she is allergic to?