hyperthyroidism/heart murmurs/arrythmia

Question
My 10.5 year old cat was diagnosed with hyperthyroidism 4 wks ago.  He had a rapid weight loss that I didn't detect until a little later because he was 23 lbs. from a CD vet diet, and I thought his gradual weight loss was due to me reducing the CD.  Three weeks into methimazole therapy with a 2 lb weight gain (from a 9 lb weight loss), he starts vomiting 2x daily.  Today, vet detected arrythmia, murmur, and a bp of 182.  I've noticed a random severe coughing, and difficulty swallowing (each about once a month).  He is scheduled for an xray tomorrow and an ultrasound in 3 days.  It's obvious he has heart damage due to advanced thyroid, but does coughing and swallowing symptoms show it has advanced to heart failure?  Please advise...I'm beside myself and believing he has maybe 6 mos. to a year only...and my own heart is broken.

Answer
Hi Anne.  Sorry to hear about your kitty's troubles!  I know you must be on edge right now, but unfortunately, only the tests will be able to say for sure.  I guess there is some room left open for interpretation, but I don't think your cat's symptoms show he has advanced heart failure at all.  A cat with advanced heart failure, the way I interpret "advanced", will be lethargic, will have lost appetite, and there will be noticeable changes in his breathing pattern.  He'll be using his diaphragm (lower abdomen) to pull in air instead of the lungs.  Sometimes there will even be open-mouth breathing.  The belly area may have fluid build up in it.  This was my cat.  He recovered after a hospital stay, and we had a good while left together.

With the symptoms noted on the exam, I'm glad you'll be following up with an ultrasound.  Even if it is confirmed that he has some degree of heart failure, don't think in terms of a life exptectancy that he has set.  Many cats are not diagnosed with heart failure until they are found in a state of crisis and brought back from the verge of death.  So when you see the "average 8 month survival" prognosis, remember that they are taking all these kitties who were in very poor condition into consideration.  If your cat IS diagnosed with heart failure, you'll be able to prevent a catastrophic episode like this, and I think you may have more time left with him than you fear.

Best wishes!  I hope all turns out well!

Jessica