Hello & welcome, I am Dr. B, a licensed veterinarian & I would like to help you with your poor lad.
Based on Bart's signs, I am quite concerned that he is in a precarious situation and that this isn't directly related to what his vet treated before with the anti-inflammatory. If he has showing all of these signs you noted, it is highly suggestive of a brain based issue. At his age, we can see this with an infection, bleed, or mass compressing the brain. Though I have to note that if he has lost his sight, this isn't likely to be something we can restore. So, in regards ***** ***** question, this isn't likely something we can cure nor the underlying cause. It may be possible to manage that but at his age often we find that cures are not possible and giving them relief from suffering has to be our main focus for them.
Please take care,
Now we don't want to be leaving him to die since that isn't fair for Bart. Though if he is breathing comfortably, has pink (not pale/white) gums, and hasn't any pain when you feel his body; then you can choose to monitor him until his vet is open. If you can keep him taking food/water (favorites are allowed, meat baby food -without garlic/onion- or bits of chicken or white fish can be offered) that would be ideal so he isn't starving and dehydrating himself. But otherwise we can give him a calm, quiet place to try to settle and feel secure. He likely feels quite stressed and vulnerable without his sight and without balance. But from what you have reported he is not in a good way but not in a situation of active suffering or distress such that he might euthanasia right now. But again we need to keep a close eye and provide what comfort we can until his vet is open.
You are very welcome, my dear.
Hello again, David.
I am very sorry to hear that he passed but it's good that he was able to do peacefully and is no longer in distress.
Please take care, my thoughts are with you.