One of my cats has noticeably cold ears, I feel pretty safe in assuming it's due to poor circulation but what are some possible causes? I'm going to make an appt for her next week but I'd like a few things to worry about till then LOL. She's 14 years old, in excellent health according to every annual checkup, and fairly active with 7 other cats ranging from 9 months to 9 years around.

The whole "warm nose/cold nose, sick dog/healthy dog" thing is one of the biggest myths that i repeatedly hear from clients in regards to animal health.  It goes for cats too but in this case i would pay more attention to her overall health (food and water intake, weight, etc).  Older cats are prone to various age related diseases including kidney disease which can directly correlate to blood pressure.  It's a stretch to say that because she has cold ears that she has issues related to her blood pressure and/or kidneys but it's something to consider.  I highly recommend running full health panels (bloodwork) on geriatric patients as part of a routine annual exam.

Ears are used to collect or flush heat from the environment.

Cold ears means the cat is trying to retain heat.

Warm ears (put your lips on the tip to feel the temp) could mean it's just using them to drain heat.

Hot feeling ears is probably a fever.

I wouldn't worry about it.  Cats are good at getting up and finding a spot they like for a temp they like.

My cats are very good a sucking all the heat out of the heat registers. :-)

I've been around a lot of cats over the last 34 years or so, and inside a room temperature house (65-80 F) I've never touched a cat that didn't have cool/cold ears. Outside in the heat? Sure, they had warm ears some of the time.

I've only had one dog with a cold nose, and it was like ice. He had a thing for snuggling with women and time after time he would touch his nose to their neck or ears and make them jump like they had touched with ice cubes.

I have 8 and this one is the only one with cold ears. Well, there's one who won't let me touch her except by accident so I don't know if her ears are cold, but the other 6 have warm ears. And little furnaces for feet.