Handling extremely aggresive cat

Tom is very aggresive at the vet. The vets told me they never had trouble handling a cat, even aggresive ones, but tom is a different story.
He's a very big cat, he is also in excelent muscular condition [and he's 15 so its surprising to see a strong senior cat], he has huge paws and huge canine teeth.

At the vet they have 3 peeple holding him and its still difficult to do anything.

The reason he acts this way is because he is tired of going to the vet for his blood glucose checked. He had never been this way before he was diagnosed with diabetes.

They can't do a BG curve.. when they tried he caused so much trouble all the vets had to have a meeting to talk about the situation and see what they could do. The BG curve was cancelled.

I was taking him to a very good veterinary place until they screw up BIG TIME, so I changed him today to another place. I was very upset that such a good, expensive place would make such a mistake. But they had learned to handle him.. almost every vet there ends up with big scratches and bites whenever I take Tom... but any work they needed to do was done.
They were also a bit rough when the held him down.. another reason why he defends himself so much now.

At home he's not like this, but at the vet he even bites me.. he does bite me a little less strongly than with other people, but if he's to stressed he can give me a big bite. Sometimes he slips away from me because he moves so much. He doesn't fall, he just manages to free himself from me.

I don't know what to do, any ideas how I can help him?
I'm in the process to learn to use a glucometer so we won't have to stress and scare him as much, but in the mean time I want him to be a little less aggresive because sometimes the vets can't do anything to him, and he needs to be handled specially in emergencies.

How can I calm him down? Both me and the vet pet him for a while, but he's not dumb, he knows he's going to be tested soon so he still bites when we pet him.

I just don't know what to do anymore
sorry this is long, I always end up writing long posts, but I want to give as much info as posible in case anything might be necesarry knowing.

Isn't there anything you can give him at home, to sedate him a little bit? A tranquiliser I mean . Poor cat, he must be really traumatised

I'm surprised they don't sedate him, but maybe it wouldn't mix well with his diabetic medication. I think the best thing is when you can measure his glucose at home.

I definitely think he should be sedated before going to the vet, or at the vet. It is not good for him to go through all that stress. Poor boy, he doesn't understand! A little dose of anxiety med before leaving for the vet, or a shot to slow him down there.

There may be a time when he has to be manhandled in an emergency situation, but for his regular check-ups they should have pity on him! He's a cat! They don't like having their space invaded, and don't want pain from strangers! Tell the vet he wants valium or klonopin or something!

I think Tom is a very handsome guy. I hope this situation gets better for you!

at the new vet they told me they would sedate him today, but the can't inject him anything because he's old and weak [he had a serious hypo] so they are worried injecting him anything strong might cause coma or death.

They said they would use some drops, I hope that helps and if it does I'll ask them for the name of the drops and use them when I hometest. I wonder if using to much of those drops will harm him?

Yes, he must be traumatised.. I didn't even consider he's scared because he doesn't understand.. poor baby

thank you for everyones advice.

I would either try to hold him yourself at the Vet (this may be less stressfull). Try to find a vet who will do house calls/ it may be less stressful if this is done at your home instead of after a stressful car ride and waiting in the vets office.

I am not really sure what checking glucose entails but ask if this is something you can do at home. For example if all they need is to take blood you can do it yourself at home and bring in the blood. My aunts cat was very sick and needed injections to stay alive so the vet showed me how to do it and I gave my aunts cat injections at home for 3 weeks until he go better. I would think taking blood is not easy but it cant be all that hard.