Is he too aggressive to bathe?

I need to know the specific indicators that a cat's distress level makes bathing unsafe or unnecessary. I'm looking at Oliver right now and he is vibrating. I wrote up the full history of his aggression and the failed attempts in Oliver's bath history, so you don't need to read that again unless you want to see the scars. My main concern is where the line is between 'he is scared' and 'he is going to cause serious injury to us or himself'. Is there a threshold? I know he hates water, but I also know he is 5 and not a kitten, so he should be able to handle it, right?

The line is usually when the pupil dilation stops being reactive to light and becomes fixed, or when the ears are pinned flat and the body goes rigid rather than struggling. In my experience with Lulu, when she gets that rigid, it is not fear anymore, it is a fight response. You can see similar signs in Signs of feline distress in water. If he is vibrating, that is high anxiety, but not necessarily the 'do not proceed' point yet. However, if he starts hissing with a low growl, stop. That is a clear warning.

lol if he's vibrating just back off man. I tried to bathe Duke once when he was 2 and he nearly took my eye out. I think the issue is you are trying to do it alone. Bathing with a helper has some good tips on how to use a second person. If you don't have a helper, maybe just skip it? Is it really that dirty? Sometimes I just wipe down the paws and it's fine.

I am so sorry, this is so stressful. Kiki is also very anxious and I am terrified of doing anything that might hurt her. I was reading Sedation for grooming and it mentioned that sometimes vets will prescribe a low dose of something to take the edge off before a procedure. Do you think that would be an option here? I don't want to medicate him just for a bath, but if he is too aggressive to do it safely, maybe that is the answer?

To answer the 'unsafe' part: if he is biting or scratching with intent to injure, it is unsafe. To answer the 'unnecessary' part: check Necessity of full baths. If he is not matted or has no soiling that can be spot cleaned, you do not need to bathe him at all. The stress of the bath is often worse for the cat than the dirt. I would look at his coat and see if you can just clip out the worst areas instead.

Thanks for the input. I think the vibration is just his baseline anxiety right now. I will try the spot cleaning approach Anna suggested and see if that is enough. If I do have to do a full bath, I will definitely need to get a friend over to help hold him, as suggested in Bathing with a helper. I don't want to risk getting bitten again.