Sedating Cat Before Bath. Cats, like people, respond differently to different meds, so if you have a sedative for a specific reason (vet visit, moving, etc.) always try it out about 2 weeks before you need it to see how the cat reacts. Before sedating the cat, prepare it first.
Start with the smallest dosage of 0.5 mg per pound up to every eight hours. If you can’t pill your cat, purchase liquid benadryl. You need to remove the calming collar before you bathe or shampoo the cat and if you want to apply again, simply seal the collar in a plastic bag to prolong the effect.