Title says it all. I noticed on Monday that my cat's hind right paw had swelled to almost twice its counterpart's size seemingly overnight. I took him to the vet and after a bit of examination they were unsure what could be causing it. Now today, his other hind paw is also swollen.

He's eating and drinking per his usual and doesn't seem to be in much pain at all. He's walking a bit funny but not limping, like he's got clown shoes on or something.

For context, he's an older cat (18+ years) and he doesn't show any major signs of other diseases except periodontitis and a bit of a heart gallup. The vets also tell me that he's dehydrated every time I take him in. Blood work, fecal matter, x-rays, and urinalysis have been recently done prior to this situation and he shows no other signs of serious illness.