I'm so sorry to read this (just catching up with this thread now). Has she had the scan yet? How is she now?
Storm went in for bloods and ct scan last week but the bloods came back completely normal. This means it is unlikely that it is a shunt which us great news. I'm also quietly confident it's nothing too serious. They think possibly bladder infection. Just waiting for results of another urine sample.
So pleased for you that your puppy didn't have a shunt. I had my puppy tested also a few months back. She was tiny, steady growth but slowl. She was also going to the toilet a lot. It was a terrible wait, I did a lot of reading about liver shunts as hadn't heard of it before then and was so worried. Her results all came back good, except for an overactive thyroid. She was recently tested again at 8 months and thyroid is normal and liver still normal. She is 9 months and 15kg so still is very small, but there doesn't seem to anything medically wrong with her. I hope the bladder infection has well and truely cleared up now.