How long has little Cleo been breathing fast?
Here's what I found on Google.
"Quiet breathing is very important to ensure the rabbit has no breathing difficulty or cold. Breathing will be very fast, especially if it is scared or hot. "
"Difficulty Breathing: Respiration rate of a normal full grown rabbit is 30-60 per minute, some breathe faster than that if it is hot or stressed. You should get to know what is normal for your rabbit. You should get worried if he/she is breathing in a labored way (long breaths instead of normal). If he/she is grunting you might want to get a little worried as well, but make sure it's not normal. If lips or tongue are bluish colored, your rabbit is not getting enough air. You need to get to the vet fast!"
"Rabbits breathe at different rates depending on their temperature, their level of activity, their growth rate, and even how thick their coats are!"