I am sorry to hear about the echo results but it's really good you found out what is going on with her heart so you can be proactive before emergency. Yes heart trumps kidneys... without that little heart pumping, the kidneys won't matter. I also recall her blood results were really positive, almost not showing signs of CRF correct?
Boo has been on lasix since day 1 (Nov 2011) and when her kidneys showed signs of elevated enzymes, we lowered the dose but never stopped it. Boo's cardiologist was very insistent that she did not feel Boo would keep the fluid down on her own. I was torn on this decision but here we are 15mos later! Due to the stress of the visits I cannot even have Boo's blood re-checked so I have no clue what is going on. So far there are no clinical signs of kidney stress and until then, I was advised not to worry. I am not made up that way... I want to be pro-active, battle both diseases head-on, etc. I guess my point here is that you have to focus on her heart (for now).
I do recall when Boo was put on spiro she experienced "fainting spells"... not completely out cold but she would raise from a nap or jump off a bed and fall over, like she couldn't balance herself. It was directly following the addition of this med so we stopped it. She has not had another episode. The episodes you described sound quite different, as they were more with May's head, but I just wanted to put it out there in case you try the spiro. I would do the lasix and have her re-checked... if that didn't do the trick, then add the spiro. It's hard to tell what drug causes what when introduced all at once. The other drug I would look into is vetmedin... this is not a diuretic but helps the heart be more efficient.
Hope you and May can take a little nap together today. Our ER typically sends all notes/test results to the regular vet the very next day... I would call the ER to be sure that is done as well as mailing you copies of all.
Keep us posted on how May is doing.
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