I'm sorry to hear this. Are they sure that it's a URI or could it just be allergy problems? Sky gets sneezing attacks and gets very congested and this seems to happen all year. My holistic vet gave him a few acupunture treatments but I don't think that they really helped him very much. He's also still taking an herbal tea pill called Er Chen by Plumflower which you can buy online. He takes one in the morning and one in the evening. It helps him some but sometimes he'll still sound bad. He goes in for his annual exam in June to my regular vet so hopefully I'll learn what might be causing this. My holistic vet thinks that it might be due to over vacinating him with the FVRCP vaccine which he seemed to be very sensitive to. Maybe your sister could take Mr. Whiskers to a holistic vet. Good luck.