Therefore, most cats that develop clinical signs of cardiomyopathy will appear to have been ill for only a few days. A few days of inactivity and poor appetite occur first. Just prior to the state of heart failure and death, the cat may become very inactive and exhibit labored breathing. The heart will have an abnormal shape and fluid in or around the lungs may be detected. If a large amount of fluid is present around the lungs, it may be necessary to remove it and take more X-rays because the presence of this fluid interferes with evaluation of the heart.
Many cases also require better visualization of the heart with an echocardiogram, or sonogram.
This is a non-invasive method for looking at the heart while it is pumping. Sound waves are used to make this dynamic study of the heart. The x-ray can tell us about the size and shape of the heart but nothing about heart function. The ultrasound can provide this information. This simple blood test can help identify an overactive thyroid gland as the underlying cause of heart disease.