Thank you for your patience. Southpaw's on/off panting is definitely not normal and any 'panting' in a cat needs to be considered relatively serious. There are a number of possible causes for your girl's periodic panting including anything from the constant heat currently, to pain, or even a primary cardiorespiratory problem. You are going to need to continue to keep a very close eye on your girl, and if she seems to start having any difficulty breathing or if she seems distressed, then you will need to get her seen by your local ER or after hours vet much sooner than Tuesday.
For now, continue to keep Southpaw as quiet and comfortable as possible. If it is particularly hot where you are at the moment, then make sure the airconditioning or a fat is turned on to help keep her cool. It is good to hear she is eating and drinking (although not as much as usual), so do continue to encourage her to drink in particular. If she isn't so keen on water, you can try making up a fresh chicken broth for her to see if that entices her. In the meantime, please keep an eye on your girl's mucus membranes, capillary refill time and respiratory rate as follows (do be careful that your girl doesn't try to bite you):
Mucus membranes - flip her lip and look at the color of her gums. They should maintain a nice salmon pink color. Get her to the emergency Vet if they appear white or very pale pink, or if they are a dark deep red color.
Capillary Refill time - this measures blood perfusion and test this by putting your thumb on her gum to apply pressure. After you release your thumb you will see the gum blanch. Capillary refill time is the amount of time it takes (in seconds) for the gum to return to a healthy pink color from the blanched white color. If 2 seconds or less don't worry - if it is taking significantly more time, again - off to the emergency Vet.
Respiratory Rate - if she is continuously panting or open mouth breathing at all tonight, this is a sign of shock and or pain and a signal for a trip to the emergency Vet.
Best of luck with your girl. If the panting seems to increase in frequency, if she seems distressed, or if she seems to be putting a lot of effort in to her breathing, then please play it safe and have her checked out today or first thing tomorrow at your local ER vet. I hope all of the above makes sense? If you have more questions or if I can help in any other way, please do not hesitate to ask! If you would like to accept my answer, please press RATE OUR CONVERSATION (I am not compensated in any other way). Bonuses are always welcome. Thanks! I hope to work with you again soon!
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