| Patent Ductus Arteriosis |
| PATENT DUCTUS ARTERIOS is the most common congenital heart disease in dogs. Females are affected more often than males. Inheritance of PDA is complex and dog's who have it or produced it should not be breed - ever. Stuies to determine the mode of inheritance or the frequency of occurance in the breeds have not ben carried out. This condition is significant enough in Collies to be mentioned. What is PDA? The DUCTUS ARTERIOSIS is the fetal connection between the descending aorta and the main pulmonary artery. When a mammal, such as a dog, child, cat is born it's body must adapt from living in a fluid environment to breathing air on their own. The DUCTUS ARTERIOSIS carries most of the blood past the heart before birth, and should close very soon after birth, when the mother's blood supply is closed off. When the PATENT DUCTUS does not close the mammal the animal has PATENT DUCTUS ARTERIOSIS. The size of the opening left determines how much the dog is affected. Surgery is the only option for this disorder, depending on the size of the hole. These breeds are more commonly affected: Maltese, Pomerainian, Shetland Sheepdog, Kerry Blue Terrier, Keeshond, Mininature & Toy Poodles, Bichon Frise, Yorkshire Terrier, English Springer Spaniel, Collie, Cocker Spaniel, German Sheherd, Irish Setter & Chihuahua. If the DUCTUS remains open longer than 7-10 days of age it is abnormal in canines. Clinical symptoms rarely develop within the first week of life, but may show up at the six-eight week veterinary examination. Symptoms of PDA Coughing Weight loss Reduced activity or intolerance to exercise Heart Murmur with a distinctive 'machinery' sound You may feel a continuous flutter at the base of the heart. Types of PDA LEFT TO RIGHT SHUNT PDA is the most common form. The blood from the higher pressure aorta is constantly pushed into the main pulmonary artery, which takes blood to the lungs. More blood is pushed into the the lungs which causes pulmonary edema (fluid build up in the lungs), and volume overload to the left part of the heart. Without surgery 60-65% of these dogs will die prematurely. Surgery is required to correct this condition, prognosis is excellent afterwards if the surgery is performed early in the dog's live (under two years old:). RIGHT TO LEFT SHUNT PDA (reverse PDA) These dogs will have less pulmonary flow. This is not well understood. Changes occur that are considered irreversible. The owner may not notice anything for the first 6-12 months. This form is not usually recognized until 18-24 months. These dogs live approximately 3-10 years, depending on the degree that they are affected. This type of PDA is managed with rest, exercise restriction, medication. Diagnosis of PDA Stethescope (initial) - murmur Electrocardiogram Radiograghs Echocardiograghs Breeding Recommendation DO NOT BREED from dogs who have PDA or have produced PDA puppies. SIblings should not be used, OR only after very careful screening for PDA. General Information Inheritance Complex, assumed to be polygenic Tests (OFA Guidlines) 1) Auscultation by a veterinarian cardioslogist 2) Echocardiogram incuding Doppler studies Interpretation of above test results (OFA guideliines) 1) Dog with no murmur, or 2) Dog with murmur found to be normal via echocardiogram, with Doppler studies. Recommended Screening & Minimum Age to Screen OFA guidelines) 1) Minimum age to test is one year old. 2) Before breeding and yearly until the animal reaches maturity (Some heart murmurs will be detected at a later age, but certainly by maturity) (Some atypical heart sounds can occur in completely healthy animals) |
