Man sorry to hear it. We lost a female Boxer in a similar way five years ago. She was only about 3. Rapid onset and within weeks of positive test results, she just lost the ability to stand or move in her own. On the bright side I think it is largely what inspired my youngest to pursue her vet tech certificate. She will be handy on the new homestead when we have more animals. She’s learned so much and she’s only a year in.