You may print off our Caudal Vena Cava Maximum Height Measurement Chart – Click here for printable PDF.

The power of this approach is that we have provided absolute values over complicated exponential formulas.  We like too say “flat is flat.”  A flat caudal vena cava (CVC) is obvious and measurements of 3-5mm are within margins of error for most of us non-radiologists.

However, the use of FAT CVC is more clinically useful.  Dogs < 9kg (<20lbs) should not have a maximum height of >1.0cm and dogs >9kg (>20lbs) should not have a maximum height of over 1.5cm as listed on our chart.  The eyeball characterization of FAT, flat or bounce, should always trump absolute height measurements.  Hepatic venous dissension, referred to as the “Tree Trunk Sign” is nearly 100% specific for increased right-sided filling pressures and right-CHF.  Gallbladder wall edema may also be caused by right-sided CHF – see IM Blog.

We measure using calipers as shown in the image using B-mode (M-mode as too much work and time for me being a non-cardiologist).  Many times I personally take a piece of paper, mark the heights, then slide it over to the centimeter scale on my machine if I don’t want to bother with calipers.

Please credit us for the chart below if you use it in your presentations.  Thank you.