If he's bloating I would not use Dyne. Dyne has been used for weight gain by many people, and at least one large well known rancher, but if you're dealing with bloat, the last thing you need is to be pushing excessive sugar into his system.
Right now concentrate on getting the bloat taken care of. Keep pushing the critical care and don't even bother worrying about him gaining weight at this point. If you're doing at least 45 mL of critical care a day, that should maintain his weight. But with his situation right now, I would be trying for doulbe that amount to try and push out the gas from the bloat.