Little Bit of trauma

Wow! What are we doing wrong! The little Miniature Pinscher is at the vet on a drip. Again! We went through the whole traumatic experience the previous time with the Scottish terrier, and now the new little bit of a dog is sick as well. I told Dries to let the dog go/die, but apparently he’s got a softer heart than me. Again, Arnia spent two nights with the little thing in her room, and she is heart broken that Petite Peu is sick. Now we beat ourselves up. We should have gone to the SPCA, or we should not have bought a dog so soon after the previous one? Or we should have gotten an older dog?
We lost all reason when we saw her on Sunday in the pet shop. She was too cute! Please, Little Bit, stay with us!