Our 10 yr old dig has not pooped in a few days it was black when he did go and now he won’t walk up/down the stairs to go outside. Should we put him down? We don’t want him to suffer. Will they do it at the shelter for animals?

T8KE HIM 2 D VET cuz it might jus need medicine & no need 2 put him dwn my dog Anubis went thru dis & all I need'd 2 do was chg his food & he is 18yrz old

Try getting help from a vet. It's hard to put a pet down without any attempts to help them. But yes you can take them there.

Our dog had the same symptoms, the vet told us it either drank coolant, or contracted a disease from a rodent it killed. When he checked her, her kidneys were swollen 3 times its its normal size.

Take it to a vet