A dog or puppy with Parvo can usually survive if the dog or puppy is treated soon enough for the Parvo.
If the dogs or puppies Parvo is left untreated then the dog can die within 48 hours of getting the Parvo.
Some dogs or puppies with Parvo may survive up to 72 hours but if left untreated for the Parvo the dog will eventually die.
So you must get the dog or puppy to the vet as soon as you think or know the dog has Parvo to increase the chance of the dog or puppy surviving it.
The Parvo Virus in dogs and puppies is a serious Virus that causes severe life threatening diarrhea, often the diarrhea has blood in it.
So parvo is a serious thing that needs a vets medical attention but even then there's no guarantee that the dog or puppy will survive but they have a good chance of surviving parvo is they get treatment.