I don't think that's true, a life is a life. There shouldn't be a price tag on suffering. Nothing deserves to live in pain and die from a treatable disease just because they'd only live to be a 2-3 years old.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry