Older bun keeps falling to sleep in random ways....should we be concerned?

Chester is about 7 years old, and he was a rescue. When we got him, he had a pre-existing injury to his back leg. Our rabbit savvy vet thinks he was dropped, and the person didn't get treatment for his foot. So, he walked lop sided, and then this caused arthritis. He is on metacam twice daily for this. He is relatively healthy, with the exception that he has cataracts on his eyes and the back leg issue. Lately though, he has been randomly falling asleep. A few times a week, we find him slumped over his food bowl, once in his litter box, and today, as he was possibly cleaning a cecal from his nether regions, he must have fell asleep that way too (his back legs were pushed forward, and he was slumped down). When we find him this way, we typically talk really gentle to him, pet his head, or from his head down his back, and we tell him that he is just dreaming. When he wakes up, it's like everything resumes normally and he goes back to what he was doing. This is the oldest rabbit we have ever had because the rest have not made it past four or five at the oldest, and all of them have had some health issues which shortened their lives. I'm just wondering if this is what happens when a rabbit starts to decline due to old age? Or perhaps this is due to the metacam?

I wouldn't say it's necessarily something to be concerned about in regards to it being a health issue that needs to be taken care of, at least it wouldn't raise any signals of concern for me, but it can be an old age issue to be aware of and continue to make sure your bun is as safe and comfortable as possible for his remaining time.

My 10 yr. old bun started doing this in her last year. She was sleeping more, her sleep was deeper, and she would fall asleep in more random places, like right in the middle of eating. She still lived a good several months after this was happening, so your bun may still have a good while left. But you should also prepare yourself, as this is likely a signal that there isn't too much longer left for him. It can be sad knowing this, but it's also nice to know you've given an animal a safe, good, and loved life, and that they were able to live their life out in this way.