Jokes aside, fortunately Algernon was uninjured by his tumble. We picked him up, checked he wasn't in pain, then continued with his syringe feeding, which he happily finished.
Some background: On friday evening me and my wife were on the sofa watching TV. Our piggies are allowed to free roam, and Algernon made his way over to the sofa and sat there looking at us. We ushered him back towards the piggie area and saw he was walking very stiffly with his back legs. When I picked him up, he felt much smaller than usual so we decided to weigh him. His weight had dropped from 788g on July 15th to 660g.
We prepared some Critical Care and fed him with a syringe which he took very slowly.
We have continued feeding him since then and despite dropping to 640g yesterday, he is now up to 680g.
A couple of times he has gone missing and we found him hidden in the room. I'm not sure if he went there purposely or got lost, but we have decided to put a fence around the enclosure for now so it doesn't happen again.
Yesterday he eaglery ate some pepper, and we have seen him drinking and eating some dried food:
He still isn't very active. He'll sit in one of the houses most of the time, but he is eating and drinking more on his own, so I am hopeful he will get better. He takes his critical care and water by syringe very well now, so I think he understands that it is good for him. He still walks very stiffly with his back legs, so a trip to the vets might be in order to find the cause. But at the moment, I'm concerned such a trip would be so stressful for him that he might regress.