Dr. M. Margaret King
Special to The Sun
Q: We recently had a litter of puppies and their mother Maddi is a champion black lab. One of the puppies was diagnosed with a patent ductus arteriosus. We had 12 puppies and only the one was affected. We kept this puppy but unfortunately it died when it was 3 months old. Can this condition even be fixed and what is its cause? She was a beautiful little girl.
A: The ductus arteriosus is a temporary blood vessel that exists in the fetus. Its function is to divert blood flow around the lungs while the baby is in the womb. It is supposed to close off just before birth to divert blood into its normal flow through the lungs.
If it does not close at birth, it is called a patent ductus arteriosus or a PDA. Patent means open, and the left ventricle has to work harder just to move the normal volume of blood. This decreases the blood flow to the aorta. If a stethoscope is used to listen to the chest, the heart makes a sound much like a clothes washing machine — whoosh, whoosh. Thus the condition is fairly easy to diagnose. PDA is not that uncommon in dogs.
Indeed, if not corrected, it is a fatal condition. The most common form of correction is to open the chest and tie off the abnormal blood vessel on both ends. This is of course a major surgery, requiring the chest be opened. The plan is a few days in the hospital, then recovery as with most major surgeries, then suture removal from the skin in 10-14 days.
Now a procedure is used to pass a catheter through an artery in the dog’s leg and insert a coil to help a clot of blood to form and block the PDA. It does however require catheterization of both the left and right sides of the heart and takes three to four hours to complete. When successful, blood flow through the heart is rerouted and the problem corrected.
As you might guess, as the puppy grows its oxygen demand increases and the PDA becomes a more dangerous condition for her survival. It sounds like your puppy might have been growing rapidly and outgrew her ability to provide sufficient circulation to the essential areas of her body due to the PDA. If you breed Maddi again there is every chance that all her puppies will be normal. You also may want to try a different stud with her next time.
DR. M. MARGARET KING, a longtime Edmond veterinarian, is a guest columnist. If you have any questions for her, email them to firstname.lastname@example.org.