10 month old having issues with his back/back legs

Good evening,

First post on a kind of negative note. I have a 10 month old, neutered, siamese mix that within the last 5 hours sporadically is having issues jumping or using his hind end. He walks very stiffly and with an arch in his back. Being the paranoid mother I am, I am super close to taking him to the emergency vet (although the price of that endeavor would be pretty hefty). Part of me wants to think he took a tumble or he tweaked it while playing with his sister, but I don't want to take the chance.

He hasn't had any change in his eating/drinking/litter box habits, but again this was a quick onset and definitely not something that I've ever seen within the 7 months that I've had him.

Am I freaking out a little too fast? Has anybody else had an issue like this with a younger cat? Do you think it's something that can wait until tomorrow to go to the vet and get checked out?

I'll try to get a video of him and his mechanics, but in the interim any help would be greatly, greatly appreciated. 

Thanks!

After watching this I'm thinking now that maybe it's an issue with his stomach? I know we don't have any poisonous plants (no plants at all, actually) and everything is out of reach from him. No switch in diet, no switch in habits. He obviously is still very aware and wants to play and has a good attitude. Any thoughts?

Hi

I was wondering how your cat is doing? I have just posted about my 10 year old cat about thrombosis and this could be a possibility as she started off the same before losing her back legs altogether.

Young cats can suffer from this but I really hope this is not the case for you as this is a horrible thing

If you can't take him in right now, at least call and see what they say. Or if at all possible bring in that video. He looks awfully stiff, like he is in pain. He's really young to have a blood clot, but it could happen. I know it's expensive, but for your peace of mind you should see vet. My heart cries for you, I'll pray for you both.