I'm sure you have already come across them, but we have worked with Rottie Empire Rescue in the past: https://www.rottieempirerescue.com/about/
You mentioned that he is in the hospital. Is it an option to ask groups who can't take him to post him to their social media and try to share him more widely? Sometimes that is a way that groups who are also tight on space can help. Or is transfer out to another org his only option?
I think sharing details on his dog-aggression could be key too, since it probably impacts folks ability to decide if he is a dog they can take on. Has he injured other dogs? If so, how badly? You mentioned that he can't be near other dogs. What is his reaction? Is he reacting to other dogs in the house? Dogs he sees out walking? Other dogs in the kennel?
Do you have a trainer who has evaluated him and could talk to groups that might be willing to take him about what they saw?
If you have someone able to work on training him to wear a basket muzzle while seeking a transfer, I often find it makes people feel more comfortable taking on these big, "tough looking" dogs who don't like other dogs. If they know that they can use the muzzle as a safety precaution for areas they might encounter a dog, that makes folks feel more confident and prepared.
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Emme Hones
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