Hello! Yes, I did just that! My parents were willing to keep the cats (I have two), but I couldn't really stand the idea of not knowing when I would have them with me again. If I had only been coming here for 6 months as an exchange student or something, I never would have brought them, but since it was for at least a full year and probably more with the International Graduate Scheme, I felt it was worth it. However, as you know the PETS Scheme was very expensive and finding a flat that allows pets isn't easy (at least in Bath).
As I said, my parents were willing to keep them for me and because of timing, the cats weren't cleared on the PETS Scheme until October, so I moved to England in September, went home for Christmas, and brought the cats back with me after Christmas in January. I'm really glad I had this option as it gave me a chance to get settled before I had to worry about them. I found a housemate on that easyroommate site who knew I was just looking for something short term as I would then be looking for a flat that allowed pets. As I said, this WASN'T easy, but I do think that's the area here. Letting agents claim that the historic buildings in town don't allow pets, and finding a furnished place that did allow them was impossible. I managed to find something, but it was unfurnished, so I did have to go to the expense of buying furniture and everything. I'm not sure what the rental market is like in Scotland and depending on where you're going to be, it could be a lot easier. I found that renting a flat in England was much more difficult than renting one in the US. Being a student with no income (other than loans) I had to have a guarantor in the UK willing to co-sign my lease. Fortunately, I have friends here who were willing to do that for me. I probably wouldn't have gotten the flat without that.
In the end it all worked out for me and I would do it again if I had to. The hardest part, to be honest, is finding a place to live. I'm really glad I had that time to find something once I got here because finding a place while I was still in the US was impossible. I'm sure there are B&Bs or hotels that allow you to bring pets which could be an option for when you first get here.
My cats are both on special diets, so I made sure they sold their brand of food before I came here. And I'm sure you're aware of the crappy exchange rate. A $30 bag of food in the US costs 30 pounds here. I wasn't too happy about that one!
I would suggest checking out the rental market in the area where you're going to live. Check the many roommate sites and even post a profile on there to see if anyone would be interested in a roommate with a pet. Look at letting agents to see what their listings say about pets. If you can't go back and get your cat later, perhaps someone would be willing to look after him for a couple of months until they could get him to the airport and he could fly unaccompanied and meet you on the other side.
Good luck with everything and feel free to ask me any questions!
Kim