Wennibear,have your husband read all the posts,most of us here have had to make the terrible decision to help our animals end a life of suffering.
You do it out of love and compassion for someone who has given you love and loyalty for many years.
Letting her go on suffering and probably die a painful death,is IMO animal-cruelty.
This is the last act of kindness your husband can do for his dog,the poor old soul.
"The cruelest animal is the Human animal"
3 kitties,Rocky(r.i.p my boy),Chico,Vinnie