Abdominal Aortic aneurysm

My 66 year old husband had a quadruple heart bypass 10 years ago , & he has just been diagnosed with an abdominal aortic aneurysm , approximately 4cm in size.
He still does a part-time gardening job twice a week , & mucks out two horse stables daily.
My question is … will these fairly strenuous activities adversely affect his condition ,  & are there precautions he should take regarding physical work ?

[kenkeith]

There is low risk of rupture if the abdominal aneurysm is less than 4 centimeters. However, an increase in the size of an aneurysm means an increased risk of rupture because the wall stress is proportional to the diameter of the vessel, and 5.5 cm is within surgery treatment..  

Your doctor will probably recommend that you make other lifestyle changes, such as following a heart-healthy diet, limiting alcohol, and exercising. Try to do activities that raise your heart rate. Exercise for at least 30 minutes on most, preferably all, days of the week.

If there is an operation heavy lifting should be avoided for several weeks.  A 4.0 cm diameter should not impose any restrictions, but to be sure you should consult with the doctor as there may be other considerations.