|Bette (left), Myrna (middle), Elizabeth (right)|
Tuesday, February 18, 2014
Myrna's Breathing Rate Suddenly Increased Monday Night
Ever noticed that your HCM cat is fine one moment but not the next? Sudden changes can occur in cats with heart disease. This is why we MUST be aware of what is "normal" for our cats in order to understand what is NOT normal and when and how quickly to react. We must ALSO understand what needs to be done, what we can do at home, and when the cat needs to see the vet immediately, even the ER vet.
Myrna's breathing suddenly increased rapidly last night. She was fine all weekend, playing, and breathing well. But Monday she slept all day although breathing fine. Granted, she does have her days when it seems, after a weekend or a couple of days of running around, she needs a break and will spend the day resting. But by the evening, her breathing rate had crept up to 10 beats per 15 seconds and by bedtime to 12 (or 48 a minute when normal at rest for a cat is about 24 and for Myrna it is 8 or 32.) She didn't hide at any time (which could have possibly indicated another pending heart attack or serious onset of CHF or other serious issue) she took all of her meds all day long, and ate well all day. But she slept in between and she did not use the litter box as often as she usually does-every 2-4 hours. Instead, she only went about every five hours. Sleeping contributed to not drinking, and not drinking contributed to less intake and output but should not have contributed to onset of congestion. So, what happened?
We gave her 3mg of extra lasix at 10 p.m. (Her normal doses are 13mg in the a.m., 10mg 2:30 p.m., 13mg 6:30 p.m., 10mg 11:30 p.m.) The breathing rate did not decrease and she only used the litter box once after 11 p.m. She was sleeping on our bed for an hour but the breathing rate never settled and remained at 12. So I gave her a .1 ml injection of lasix at 12:40 and within 20 minutes she used the litter box. She went again overnight and again at 5:30 a.m. I did not give more than .1ml because she had already had so much lasix. I would have given .15 as I have before if we had not just given her 26mg of lasix over six hours or if the breathing was far more serious than 12 (at which point I think I would have taken her to ER vet.)
By 5:30 a.m. today she seemed to breathe normally but was walking around and I couldn't get her to settle to count. But her sides weren't heaving when she was sitting. By 10 a.m., she had breakfast and still seemed to breathe more normally which for her is still high at 8 breaths per fifteen seconds.
There was nothing that we know of that contributed to sudden onset of congestion. No noise, fumes, or visitors occurred yesterday. I emailed the vet and told her what happened. I explained that yesterday she did not urinate enough and I asked how that may have contributed to congestion or if it is a symptom of congestion. When Myrna urinated, it was the same large amount but she only went every 5 hrs instead of about 2-3. I asked the vet if we should be concerned about kidney function. That she's producing urine in large amounts shows that the kidneys are functioning. But not getting rid of fluid leads to congestion. Here's what the vet said:
"It sounds like you did a great job getting her back on track last night. Today, give her 13mg Lasix for her first 3 doses of the day, then you can decide if her final dose will be 10mg or 13mg based on her breathing/urinations/activity throughout the day. It sounds to me that her kidneys are developing some tolerance to chronic diuretic therapy. This is a known consequence of diuretic therapy and it necessitates increased doses of Lasix. While it's encouraging that she's still urinating regularly, we do still have to be concerned about the effects the higher Lasix doses may be having on her kidneys. Once we're happy that she's stabilized, she should get in for a blood panel. It may be best to just come to our office to do that so we can reassess her heart at the same time..."
Perhaps I waited too long last night to give Myrna more lasix. That Myrna slept all day and did not use the litter box often enough is not itself a symptom of the onset of congestion. We cannot be proactive and give more lasix when it is not warranted, when signs of breathing difficulties do not present. But we can learn from this incident and understand that not going often or enough can mean a tolerance to lasix has been reached and that breathing must be monitored more closely and more lasix given sooner once we realize that the breathing rate has increased. We will increase the lasix today and continue to monitor and I will make an appointment to see the cardiologist for later this week.