Will Falconer, DVM Moderator
Oh, God, Mary, for an 11 month old to be reduced to illness like this for 2 weeks duration is truly heartbreaking. Especially crying all day! He's really uncomfortable and you're not getting support for your clear observation that it came on a day after the drug.
Here's perhaps a Hail Mary pass now that we're two weeks in, but worth a try to detox him: https://vitalanimal.com/detox-report/
Please do report back and let us know if this helped.