This from The Times:
"The dogs, which had been kept indoors for several weeks and were said to be aggressive and in poor condition, were killed with a captive bolt gun of the kind used in abattoirs to stun livestock before slaughter. The use of captive bolt guns is deemed “inhumane” and “unacceptable” for the destruction of dogs by the World Society for the Protection of Animals (WSPA)."
Why do we owe dogs a more humane killing than livestock? Humane killing for all I say. Better still - no avoidable killing at all! We don't need to eat meat.