Abdomen expanding when breathing/not eating

for about 4 days my 12 year old cat has been breathing heavy - her whole abdomen expands when she breathes, she is lethargic and hasn’t been outside for days - just lies down. When she moves/changes position she then almost pants through her mouth. She has also stopped eating and drinking. Is she at the end of life?

Hello - and I'm afraid that I'm worried.  Struggling to breathe (dyspnoea), lethargy, mouth breathing and refusing food is a very concerning combination of symptoms.  Whether she is necessarily at the end of her life, however, may be debatable. We have no way of knowing from text over the Internet what is causing her symptoms:  many causes, such as certain cancers, can be very difficult to treat but others (diaphragmatic hernia, for example, after being hit by a car) might have a better outlook.  It sounds as though a differentials (possibilities) list and a conversation about likelihoods is in order, and it also sounds as though this may be an emergency. Please contact your emergency vet, who may be able to help you to understand the options and your cat to feel more comfortable.