I wonder if saying something like I’ve researched the options and this is the insulin I want to switch to would help...? Being the owner, you should have some say on what medications you want your cat on. Like a human would be able to tell a doctor what it wants and what it doesn’t want.
Yes, it certainly can help if a caregiver can tell the vet that they've researched the options regarding the different insulins (and the vet can be reminded of the international ISFM guidelines which recommend the use of longer lasting insulin). It also helps hugely if the caregiver is regularly testing blood glucose at home and can show that they have a good understanding of their cat's diabetes.
But nobody in the UK has the 'right' to ask for - and expect to given - a certain insulin.
In the UK the standard requirement is that a vet prescribes a veterinary medicine for animals. If the medicine that the vet prescribes isn't sufficiently effective the vet can use something else that may be more effective. If there is another veterinary medicine available the vet would probably prescribe that. In terms of insulin though that would
currently mean prescribing a human insulin, such as Lantus or Levemir. It is not difficult for vets to do this, though some will have never done this before. There are now quite a few UK cats on Lantus or Levemir.
As said earlier, the attitude of vets varies enormously when it comes to prescribing human insulins. Some vets actively promote their use (and a tiny minority will even prescribe human insulin as a first choice despite the UK requirement for prescribing a veterinary insulin first.) Some vets may not have used human insulins before but may be open to prescribing them. Some will steadfastly refuse. Some don't even know that they 'can' prescribe human insulins. ...If a vet refuses outright, then there is always the option of trying to find a vet who is willing to prescribe a human insulin. Some people have done this. Sometimes another vet in the same practice is more open to prescribing human insulin, sometimes it involves moving to another vet in another practice.
There is a big element of luck involved too. There are quite a few people who, despite their best efforts, can't get access to a vet who will prescribe a human insulin.
It's important to remember too that some cats have done just fine on Caninsulin. While it is not so much used in the US these days it has been widely used in the UK and much of Europe, and other parts of the world. And because we've had to use it we've learned ways to get the best out of it.
Whichever insulin a kitty is on this forum is always here for advice and support.
@Julie & steve j - Useful reference info here should you need it, the ISFM guidelines and some info from the RVC. And for general UK info see link in my signature.
https://journals.sagepub.com/doi/full/10.1177/1098612X15571880
https://www.rvc.ac.uk/Media/Default/small-animal/documents/feline-diabetes-guide.pdf
