My cat has uneven pupils and a heart murmur. What symptoms should I watch for?

Hello and thank you for reaching out to Petco Pet Education Center, formerly Petcoach. When cats pant or breathe with their mouths open, this is abnormal and concerning. Given the information you provided about the Merlin's heart murmur, I am worries that he could have significant enough heart disease to cause heart failure, which leads to the build up of fluid in the lungs. This makes it very difficult for cats to breathe, especially after exertion, and can be life-threatening. Alternatively, cats can pant when they are severely overheated, which is also very dangerous. I would recommend keeping Merlin quiet (no running or playing) until he can be seen by a veterinarian. He/she will want to do a full physical exam and take x-rays of Merlin's chest to look for heart enlargement and/or fluid in the lungs. There is a blood test available called an NT-proBNP that can detect heart failure in cats as well. I hope this information is helpful!

Thank you for the additional information. Heart murmurs can affect the breathing in a couple of ways. One is that the murmur often times is due to a leaky valve which means the blood is flowing backwards, which then causes fluid to back up into the lungs and breathing to be more difficult. In cats, this fluid can also build up around the lungs and press in, decreasing lung volume. We hear heart murmurs because of turbulent blood flow and this turbulence increases the risk of forming blood clots, especially in cats. If these blood clots then break off, they can travel through the body and lodge somewhere. If the clot ends up in the lungs, this is called a pulmonary embolism and can cause difficulty breathing. It sounds like she's improved a bit, but if she's still gasping, it is an emergency and she needs to be seen by a veterinarian right away.

Yes, unequal pupil sizes can indicate trauma or neurological disease. Schedule an exam with your veterinarian today or tomorrow at the latest. Monitor for ataxia (wobbly gait), weakness, lethargy or head tilting.

That is concerning. How long ago were those test performed? Sometimes as disease progresses, it becomes easier to see on xrays or echocardiogram, so I am wondering if repeating some tests may help. If its been more than even day, things can change dramatically on Xray. A young cat (he is listed at 7 monhts old) should be able to play and be quite active without panting, certainly panting is abnormal after only mild exertion. I recommend that you take him back to your vet, or take him to a veterinary internal medicine specialist. I'm so sorry he's not feeling well! Thanks for asking Petco Pet Education Center, formerly Petcoach.

Thanks for using Petco Pet Education Center, formerly Petcoach! Good job noticing such a small change. This is only a reason of concern if it continues. Sometimes cats can have some minor trauma that may result in pupil constriction and will go away on its own. If this continues though and it is still present in a few days, I would recommend that you have Harry evaluated by a veterinarian for further assessment and treatment. Good luck and have a great day!

It's possible but from my experience either the murmur was there before or it was missdiagnosed. either way a murmur without any symptoms does not require you to take him to the cardiologist, it's mainly optional, most pets with a heart murmur will never have any heart problems.

I am sorry to hear this! I know how worrisome it is to have vague signs with no other hints! If not done already, I would recommend having bloodwork and an x-ray done. Some things I would want to rule out- heart/lung disease, signs of infection, and parasites. If this all appears normal I would also consider a sedated exam to see if there are any abnormalities in his ears or mouth- like a polyp. If the behavior worsens and you do not find any answers on the other tests I would also consider advanced imaging like a CT. I hope it is nothing serious but it is good to know your options!