[AITA] My wife put down our dog without telling me while I was out of town

So, this just happened, and I’m still trying to process it. My wife (36F) and I (38M) have been married for 10 years, and we’ve had Bella, our golden retriever, for 12 of them. Bella has been my rock. She’s seen us through a lot—moves, job changes, family issues. I always felt like she was my companion as much as she was our family dog.

I had to go on a work trip for about a week, and before I left, Bella was slowing down a bit, but she wasn’t that bad. She was old, yes, but still getting around. I asked my wife to keep an eye on her, and she agreed.

Fast forward to yesterday, I get home from the trip, and the house is eerily quiet. No excited barking, no Bella waiting at the door. My wife comes out of the kitchen, and I immediately ask where Bella is. That’s when she tells me she took her to the vet and put her down.

I didn’t even know Bella was that sick, and my wife made the decision without me. I wasn’t there to say goodbye, and I feel completely blindsided. I lost it and told her she had no right to do that without telling me first. She got emotional and said Bella was in pain, that the vet advised it, and she thought she was sparing me from seeing Bella suffer. But I just… I can’t believe she didn’t even call me. She knows how much Bella meant to me.

Now, I’m heartbroken and furious. I get that maybe it was the right decision, but it feels like I was robbed of my chance to say goodbye to my dog, my best friend. My wife’s been crying and saying she did it for Bella, but I can’t shake the feeling that she overstepped in a huge way. FYI - my wife has a habit of overreacting to things, and I'm afraid she did it this time as well. I've called the vet but haven't gotten a response yet.

AITA for being angry and thinking she should’ve waited to at least talk to me first? Or am I being unreasonable?

Update: I talked to the vet. I don't know what to think anymore. Vet is obviously not going to say "it was completely unnecessary". I don't know how to process. I could use support here.