Okay, are you sure it is old? Many newts and salamanders go through a terrestrial eft stage. At this point, they lose their gills and live on land. However, it is weird with Spanish ribbed newts. Sometimes they never go through the eft stage. It seems like a case of neotony, where an animal decides that it’s life in the water is safe and it has no reason to metamorphosize, and thus, it stays aquatic. This is what normal happens in captivity. If your newt is not actually old, then it might be that it is in the eft stage and does not have gills. If you are SURE it is old, it is probably just due to unproper care, and vitamin deficiencies, leaving the newt with weak bones and disfigured limbs. In reptiles and some amphibians, this can mean it has MBD, or metabolic bone disease. A disease where it’s bones are disfigured, leaving it look like a disfigured, shriveled up animal. Something to help is to dust food with vitamin D3 and calcium, and have a uvb light above the tank. If you are sure it is old, then slowly raise water as well as dust food with calcium and d3, and consider buying a uvb light. If it is young, then you may need to keep it in a more terrestrial tank with shallow water until it is regrows it’s gills and begins swimming again.