If you talk to the vet, you could perhaps ask about anabolic steroids. Not the same as corticosteroids, as you know. Anabolic steroids build up the muscle and increase appetite. The vet can also give Vet B injections, which can help all round.
Is he anaemic, do you know?
An interesting thread here:
http://forums.rabbitrehome.org.uk/showthread.php?458170-E-Cuniculi-and-losing-weight
Thank you for the info. There's been no mention of him being anaemic. The vet said to bring him in in a week to see how he's doing. Is that sufficient?
Also, the vet hasn't given metacam, from what I'm reading this should have been given alongside the Panacur?
He hasn't been officially adopted by us yet, as we just brought him home to try to see if he'd get along with Rose when we noticed the tilt (him and Rose haven't met, just live side-by-side at the minute), so this is all being done through the rescue's vets..
Should I be concerned about him being housed alongside Rose?