Introduction
Signs of patent ductus arteriosus (PDA) in domestic dogs can take years to develop, but some dogs show mild signs from this disorder as early as one year of age. It is critical to detect PDA as early in a dog’s life as possible, because this congenital defect is almost always surgically correctable. Surgery has a much better chance of success if the PDA is detected before the onset of congestive heart failure or other irreversible heart damage. Also, reputable breeders will want to take affected animals out of their breeding programs.
Symptoms of Patent Ductus Arteriosus
Owners of affected dogs may not notice any symptoms of PDA. Most cases are identified by a veterinarian during the initial puppy wellness examination and vaccination visit, based upon hearing a loud, continuous heart murmur when ausculting the puppy’s chest (listening to the heart and lungs through a stethoscope). When symptoms do become noticeable, they are typically signs of congestive heart failure and can include one or more of the following:
- Palpable heart murmur; feels like a washing machine churning behind the dog’s left elbow.
- Bounding pulse
- Exercise intolerance; tiring with exercise
- Failure to thrive
- Stunted growth
- Weakness
- Fatigue
- Lethargy
- Respiratory distress – difficulty breathing (dyspnea); rapid breathing (tachypnea); shallow breathing
- Cough
- Seizures
- Collapse; episodes of fainting
- Death from congestive heart failure if not treated
Dogs At Increased Risk
For some unknown reason, female dogs are more likely than males to retain a patent ductus arteriosus. This is a heritable condition. Predisposed breeds include the English Springer Spaniel, Maltese, Pomeranian, Yorkshire Terrier, Shetland Sheepdog, Keeshond, Bichon Frise, Collie, Chihuahua, Cocker Spaniel, German Shepherd, Cavalier King Charles Spaniel, Labrador Retriever and Standard, Toy and Miniature Poodle.