[OT] What madness is this?

I am not a veterinarian and I have no medical training at all so someone needs to explain something to me: how does it make ANY sense to kill an animal to determine if it has rabies?
https://www.ctvnews.ca/lifestyle/orphaned-squirrel-who-became-social-media-star-was-euthanized-after-being-seized-from-new-york-home-1.7096204
An orphaned squirrel and a raccoon - the squirrel was apparently featured on a popular YouTube channel - were seized by authorities and then euthanized on suspicion it MIGHT have rabies so that it could be tested for the disease. Is there no way to test for rabies in a squirrel or a raccoon that doesn't involve killing it first?
Can't they do a blood test or examine the saliva or something of that kind to see if an animal is rabid?
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Rhino