One of my english springer spaniels is going in for what will probably end up being 2 operations, one on either back leg. The issue I have is, I will need to crate her to keep her still so she can heal and so that the pup doesn't play with her and hurt her. I currently have a 36 inch crate, but being a really small spring of only 10.5kg and more the size of a small/medium working cocker, I would estimate, she can get quite a wriggle on in there and not just turn, stand and stretch out. My question is what size crate should I downsize to to keep her comfortable but to also stop her being able to move too much because in the 36 inch she can almost have a stroll she is so small in it. I'm pretty certain a 30 inch would be comfortable for her and probably not too big but would appreciate input, especially if you have a similar sized dog.

I'm going to try and take her out to a pet shop to try her for size in some, but input would be appreciated.

Well my Elkhounds would fit happily into a 30 inch crate if the standard ones were 2 inches taller (usually 24 inches tall), I have one this size but because it is rounded at the corners is ti taller at 26 inches. 

So you may need the next size down again to really keep her immobilised.

Thank you for that. I don't have a great concept of what size your dogs are having never seen one in the flesh. I have a fabric crate the next size down but worry it is slightly too small although she likes to sleep in it if I leave the door open and there is none of her hanging out. Not sure if she could stretch out if she wanted to though? Never thought of the smaller one we had till now, will have to get her in it and see if it will do the trick. Although it is looking more like management than ops now after seeing the specialist who had a very different view than our GP vet and thinks she might have HD... Tommorow will tell.

Again, thank you for that, you might have just saved me a bit of cash that I can spend on spoiling her instead.