I was in the same situation you are just a 2 weeks ago. Our dog Maggie was a Lab/Retriever mix. We had her for 16 years and got her when she was 10 weeks old. Almost a year ago I left for work and realized I forgot my lunch. I returned home to find her limping around. I thought maybe she got something stuck in her paw. I looked and she was panicked so I put her in her crate, gave her some anxiety meds, and left for work. I took her to the vet and she’d torn her CCL (our ACL/MCL). We neglected surgery because of age and price. She started to get better but these last few months she wouldn’t eat much, slept like she’s done her entire life.
@dukiejay mentioned that of robbers would break in our doggie Maggie would assist. Two weeks ago we came home one night to find her laying down and not able to move. Two Fridays ago she was the same way. I’d stand her up and she’d walk a few feet and then fall over.
I told you all that to say...I feel your pain. It’s the hardest, most difficult, painful decision I’ve ever had to make. I cried like a baby all Friday. She’d given us 16 amazing years and I couldn’t stand to see her in pain. When I took her to the vet, she hated the vet but loved the doctor, weird I know. If she could’ve talked she woulda said Thank You. I’ll pray for you, your family, and that your decision be easy.