Best food to 'fatten' a rabbit?

Since Desmond seems to be fighting everything to stay alive, after his fly strike due to urinary incontinence from EC, he has lost weight over the last couple of weesks since the fly strike incident. He is eating everything, and forever hungry. He has changed from a scaredy bun who runs away from me, to a bun who comes over to me all the time asking for food!! He is eating pellets, veg and plantiful hay, but what can I give him to bulk him up abit. I haven't weighed him as stressful for him, but he feels skinnier. He is amazing to still be here after all he has been through. He was never a big bunny, about 1.35kgs in the first place I think.

You could try some porridge oats. I did about 1.5 teaspoons in a little bowl, mixed with boiling water and left to cool. My boy liked it more on the runny side (he was about 3.5kg)

ETA, I only fed for a couple of weeks carefully - as Jane says too much carb can cause problems too.

Firstly I think it is important to establish if there are underlying reasons for his weightloss despite the fact he is eating so well. Has he had a full blood profile run to check his kidney and liver function ?

As for what extra to feed him, well that will depend on what the cause of his poor condition is. Feeding too much in the way of carbs can lead to gut problems.

What pelleted feed do you give him ?

He lost weight due to feeling sorry for himself whilst being treated for and recovering from fly strike. He is better in himself now, although a bit bald round his back end. He has had EC, and is incontinent due to this. He is well now though. Their main diet is excel pellets for adult rabbits, hay and veg.

Has he had his kidney function checked ? If he has had EC then renal damage is a possibility and this will influence his dietary requirements and how best to help him maintain weight.

If he is in CRF then he may need medication to try to keep him as stable as possible for as long as possible. Muscle catabolism occurs in CRF which can account for weightloss and general loss of condition.

Given his history it may be a bit more complicated than simply 'fattening' him up.