Growing up I had a mix poodle/cocker spaniel. We got her in 83, finally put her down in 00, she went blind in the last year and had so much trouble walking in the last couple of months on top of other health problems, she was on meds for about 3 years. We had to guide her outdoors with a broom or hands to make a shadow (that's the only thing that kept her walking straight). Made the decision when she was outside and just laid outside in her own mess not wanting to get up. Pretty sure that was her way of telling us it's time.