I have to admit that it sounded pretty alarming to me too. But given that the OP stated that it was a known issue, it seemed best to accept that OP and her vet knew what they were about. If she tells us that the underlying medical issue is under control but she needs help moving her dog, then I think that is the issue we should focus on.
OP I'm glad that treats were able to get your boy up and moving. Is there some way you can cordon off the slippery areas until he figures out rugs?
I remember when my DH's late Buta cat got older he had trouble getting up to walk too, especially on slippery surfaces. Sometimes, when he went down, he was really frantic to get away but he didn't want us to touch him. The frustration of not being able to get back up made him lash out aggressively at us. In the end DH was forced to close off parts of the house to minimze the traumatic episodes. To make up for it we all spoiled him with extra treats, loves, toys and scritches those last few months.