Thanks I'll try the pedialyte bath, we don't have that over here in the UK, but I've used a similar product in a gecko slurry.

I've posted this on a reptile forum in the UK I'm a member on and have found out I'm not the only one that's having this issue. Another member there who also purchased a trio from the same breeder has two ill frogs with the exact same symptoms

When I emailed the breeder about the first one passing after 48 hours the response I got was pretty much "oh well". So not too happy at the moment