[OhBichonPlease]

I had a similar issue with our older female Bichon Frise from the local shelter. She wasn’t likely abused and certainly didn’t suffer the way your dog seems to, but we definitely suspect some kind of neglect. Not only was her coat shaved down almost to the skin [probably due to matting], she had ticks and fleas and couldn’t even jump up on our low mattress because her muscles were weak and under-developed. [The shelter said she was 5, our vet says closer to 8]. She has had some weird behavior with toys as well – she doesn’t seem to know much play behavior even though she was living with other dogs and it has taken some time, patience and conditioning to get her to where she is now.
She is only interested in plush toys and now she loves squeakers… but she wasn’t like that in the beginning. No rope or rubber toys seemed to entice her and she would immediately drop an item if we started to tug back – no rough chewing. We got her a plush toy and she seemed to like carrying it around, hiding it in dark corners, and gradually got more bold until it squeaked in her mouth. Sometimes she licked and coddled it like it was injured. It was hilarious to watch, but she was terrified and suspicious for the most part. After that, she would run away to another room and stay there whenever we tried to engage in play with a squeaking toy. A few times we hugged her still and squeaked a toy and she struggled mightily to get away. After about two weeks of daily desensitizing sessions, she finally learned to love to play with her plush squeakers. A squeak is enough to get her to come to a room. She loves attacking her toys [prefers hedgehogs, bears and other brown woodland creatures] until the squeaker has died. She is learning the basics of fetch, but is still very polite with her toys. We don’t think she has ever really played before.
I wouldn’t get rid of the toys, but instead show that they are superfun by having all household members plays with it in happy voices for a few minutes a couple of times a day. Don’t push it, but let your dog know that it is okay to take joy in some little things!