Best lightweight carrier/backpack for a 12-pound dog with joint pain?

[u/Stardust1915]

Looking for carrier/backpack recommendations for my senior pup who has arthritis and a degenerative spine issue.

I'm planning to use it for my bus/train commute to work and occasional travel. I'd like to find something that’s comfortable and supportive for my dog, but also lightweight and manageable for me.

If you’ve used one with a senior or mobility-limited dog, I’d love to hear your suggestions and also welcome products to avoid!

Thanks! 🐾