Many of us probably had cats that were diabetic for a while before being diagnosed I have even seen the odd one here diagnosed accidentally when they were getting bloodwork done for something else unrelated, like a dental.
You hold the syringe, it is your decision what to do about the dose increase. Just be warned that waiting too long on a dose that isn’t working can cause glucose toxicity. Which basically means his body starts to think of these higher numbers as the new normal. And you end up going to an even higher dose to break through. SLGS is our go slow protocol, cats don’t need to adjust to starting insulin like that. Plus, the sooner you get a cat regulated, the higher the chance of remission, should that be one of your goals. If you wait to increase, be on the lookout for those BG numbers to creep up.