Elderly dog with vestibular disease

[Iused2BanOptimist]

Our working cocker spaniel has been very healthy until relatively recently. She is 15. She had some terrible episodes of diarrhoea a couple of years ago but the vet thought it was a food allergy and she has a low allergy diet and has been fine on that with no further episodes.
Last year she had an attack of vestibular disease, we thought she'd had a stroke but the vet diagnosed Vestibular and all the classic symptoms fitted, she just had something for the sickness and it got better over a couple of weeks.
Now she has it again, on Sunday she was staggering in circles, her eyes spinning, head shaking. I settled her on her bed with a blanket covering her head so she was in the dark and she slept quite well. Monday and Tuesday she was improving slightly though still unsteady on her feet.
Today she is much worse again.
I've been looking on line and Fitzpatrick referrals (of course) list a long range of investigations and treatments the NHS would be proud of if it happened to your Gran.
I take a more pragmatic view that, much as I love her, this is old age and the only thing I am prepared to do is keep her comfortable.
What is the point of things like MRI's - it's quite obvious what the diagnosis is.
AIBU? Any advice?

She needs a steroid injection and a course of antibiotics. Our springer gets this and that is the treatment she gets. She's 13 and this time recovery has been slow but she is very happy now

She only had treatment for nausea last time. She hasn't been sick this time. Also I just read that steroids are not proven to work. It depends if the cause is an inner ear infection. I think it's worth checking this out but it wasn't the cause before. Just elderly dog problem. It's horrid to see her like this though.

Has she seen a vet? However similar this attack is to the last one I don’t think you should be diagnosing and deciding on no treatment without a vet involved.

At her age I would want to keep her comfortable and make sure she did not suffer.

Treatment doesn't need to be specific to the cause. It's unlikely you'll ever know the cause without intense investigation. She just needs broad spectrum treatment for likely causes.
Steroids for inflammation and antibiotics for infection.
Honestly can't understand why you haven't seen a vet for this?

Also you cannot diagnose an inner ear infection just on examination. You won't know if that's the cause on a basic exam. You just need to cover all bases and keep her comfortable. Vestibular tends to clear up fairly easily. In older dogs it sometimes doesn't disappear entirely though.

Did you make it to the vets? I hope it was better news than expected.

MRI scan will distinguish between peripheral and central vestibular disease. Treatment would likely depend on which type.

Vestibular disease can be very distressing for the dog. Please seek veterinary treatment. At that age I personally wouldn't seek investigations, I would just seek advice on keeping the dog as comfortable as possible. But a vet is the best person to advise how to properly care for a dog with vestibular disease