Elanco, has a Parvovirus treatment!
https://my.elanco.com/us/parvovirus
Now, rather than treating symptoms and praying like mad that your puppy makes it there is an actual treatment. Hopefully will be approved in 2024 but it is available now.
I first saw Parvo as a child, I was about twelve - mid ‘70s. My dad bought an English Bulldog puppy. Fabulous puppy , all rolls and wrinkles. He got sick shortly after coming home. Despite everything my dad did he lost him. I have brought home multiple stray puppies as a teenager that ended up with Parvo and we lost.
I also had a litter more than a decade ago that luckily all recovered but it was the scariest three weeks of my life. Trained as a trauma RN I know got my puppies through as it was 24 hr care for nine puppies.
Talk to your vet if you suspect you or someone else has a sick puppy. This is available now.