Back when I was a kid most excess kittens around here were put in a sack and drowned.Older dogs were put to sleep by shotgun blast. Peta put’s to rest more animals than any other agency.
Old Shep may have been a mighty good dog, but the fact is Old Shep needs to be put to sleep instead of allowed to suffer. This man had the dog for 10 years and it probably hurt like hell for him to have to do the job, but he did it, and if his conscience is clear what business is it of anyone elses how he did it.
I rented a house on a farm awhile ago. The young daughter thought cats always had one baby. (The rest ended up in a burlap bag in the lake.) I thought that was cruel at the time - still do to a degree. But I figure its none of my business.
I did put our pet rat out of its misery - it had been twitching and running around its cage. A call to the doctor said that was common for older rats - I forget what it was now, a brain tumor I think. Not wanting to spend the $ on a vet to put a rat to sleep, I hooked up the car exhaust to a bag around the entire cage. It took about 5 seconds and was sad to see - but less so than his extended suffering.