Congenital defects are those that have been present since birth. Thankfully, they are comparatively rare, accounting for only 5% of the cases seen by vets.

Congenital defects will usually cause the blood flow through the heart to become turbulent; making a distinctive whooshing noise that vets can hear using a stethoscope. That's what is meant by a 'heart murmur'. However, if your vet tells you they've detected a heart murmur in your dog, it's not necessarily cause for concern.

Many puppies are born with a slight heart murmur (or puppy murmur) that clears up by itself after 4-6 months. In many cases, vets will simply recommend a later checkup, just to be sure that the condition has resolved itself.

Pronounced heart murmur is quite rare, but may be indicative of a serious congenital defect. However, without specialist experience and equipment, it can be difficult for a GP (General Practitioner) vet to know what defect is causing the murmur. For this reason, if the murmur is pronounced, or persists beyond puppyhood, patients will often be referred to a specialist cardiologist.

Please click on the links below to find out about the more common congenital defects:
 

• Patent Ductus Arteriosus
  a blood vessel used to bypass the lungs of pups as they develop in the womb fails to close after birth.
   
• Pulmonic Stenosis
  the flow of blood from the right heart to the lungs is hampered or blocked. 
   
• Aortic Stenosis
  the flow of blood from the left heart to the body is hampered or blocked. 
   
• Hole In The Heart
  a hole between the pumping chambers of the heart. 
   
• Other Conditions
  a number of other rare defects of the heart that occur in puppies.