Hope some one will come along and answer your question soon about diabetic pets in Turkey.
We had to have one of our dogs tested for suspected diabetes here in Turkey recently and I was told by our vet that should the result be positive, I would need to get the insulin from the pharmacy here. He said it was normal and no problem.
Turned out the test was negative, so wasn't required.
But what I can say is that, I have been to the Pharmacy many times with a vets prescription for our pets!
This includes asthma drugs - which was steroids, and two different inhalers. Also more recently eye drops from the chemist for our cat who had an eye infection.
Seems to be the norm here for certain things, but I understand yours is a more specific question about the kind of insulin prescribed.