My 7 year old cat has a heart murmur (from birth). Recent blood test shows NPBO? of 1238.

A rise in BNP Cardio levels indicate a worsening of a cardiac disease. A fall in the number indicates an improvement. For the lab we use a level of 1238 is a significantly high level. However, it does not mean the use of CBD oil would be unsafe to use with your cat. The larger question is if the CBD oil would significantly lower your cat’s anxiety. The reality of CBD is that results are variable and inconsistent with the same patient. I would suggest you try CBD oil in your home environment before depending on it for your move. If it does not provide significant relief of your cat’s anxiety you could contact your regular veterinarian for an anti-anxiety drug.