If Mya started panting after playing suddenly, that may be a sign that something might be wrong. If is has been hotter than normal, and suddenly, that might explain the panting. It is difficult to say without the ultrasound whether she has a problem or not, unfortunately. She seems quite healthy otherwise, but if the panting is a dramatic change, having the ultrasound will let you know what is going on with her.
A kitten turned up in my family's yard. Because of her tanish-grey coloring and the black tufts on her ears, we at first wondered if she was a bobcat kitten. A quick look at bobcat traits (she has a long black tail, no ruff of fur around her face) proved that not to be true, and we figured she was just a slightly odd-looking stray domestic cat. We took her in.
There are various different causes for rapid breathing which may include infections, pain, heart disorders, dehydration among other causes; a cat’s respiration should be below 30 breaths per minute when at rest but if it is significantly above this rate at rest I would suggest visiting your Veterinarian for an examination to determine a cause. Regards Dr Callum Turner DVM