Cardiovascular Clearance Exams
Please NOTE: You must complete an application and an Examination Result form (e.g. an OFA form) to Schedule a Cardiovascular Clearance Exam. Please follow the preceding link to obtain forms and instructions.
While the terminology isn't universal, VVCS makes a clear distinction between a Cardiovascular Screening Examination (CSE) and a (Cardiovascular) Breeding Clearance Examination (BCE). Both examinations are conducted by a board certified cardiovascular specialist, but there are significant differences in sensitivity, for detecting cardiac abnormalities, and cost. Recently, the American College of Veterinary Internal Medicine Cardiology subspecialty has clarified the nature and goals of these examinations, describing different tiers of examination or clearance. Please see the ACVIM Website for official information. IT IS STRONGLY RECOMMENDED that you become familiar with that information before investing in clearance examinations for your breeding stock. Examination for specific cardiovascular abnormalities qualifies dogs and cats to participate in a registry, a database that indicates the health status of individuals. The Orthopedic Foundation for Animals (OFA) and the ACVIM Registry of Cardiac Health (ARCH) are registry examples and most breeders are familiar with the former.
By our definition, a Cardiovascular Screening Examination is nothing more than a careful cardiovascular physical examination. The most important part of the examination consists of auscultation, listening with a stethoscope for the detection of abnormal heart sounds such as murmurs. This examination is appropriate at any age and is suitable for determining an individual's cardiovascular health at the time. It cannot rule out minor cardiac abnormalities, heart diseases that only manifest physical abnormalities after a year of age, or congenital defects that notoriously do not manifest physical abnormalities at all until/unless they are severe. Examples of the latter include tricuspid dysplasia, mitral or tricuspid valve stenosis, and atrial septal defect. Young animals can be screened using this examination to determine whether they are suitable for sale with reasonable assurance of cardiovascular health. VVCS issues a report with this examination that can be presented to a prospective pet owner, indicating the outcome of the exam and the suitability of the pet for sale. The report stipulates that mild abnormalities may not be detected and that perinatal disease may still develop after the examination. (Subaortic stenosis, for example, is a condition that may not be detectable at birth but increases in severity over the first 6-12 months of age.) A CSE is relatively inexpensive, can be performed quickly, and can be used to screen litters of animals. However the exam must be performed in a quiet, secluded environment and it may be necessary to sedate an individual if required by the cardiologist. A panting, squirming puppy can sound like it has a murmur, when it doesn't. Alternatively a significant cardiac abnormality can be missed due to the additional background noise caused by an uncooperative patient.
A cardiovascular Breeding Clearance Examination at VVCS includes the same physical examination as a CSE and also includes an echocardiogram with Doppler echocardiography. Additional tests may also be necessary depending on the circumstances. A BCE is suitable for animals intended for use as breeding stock and may take an hour or more because of the Echo/Doppler study involved. Obviously this is more extensive and expensive and a BCE is more sensitive to detect diseases that do not manifest abnormalities on physical examination. Dogs must be greater than one year of age to obtain an OFA certification document because of diseases that are not necessarily apparent at birth. A BCE rules out congenital heart disease to the best ability of the cardiologist. This can't be done without an echo/Doppler.
Some tips for breeders:
- Do not consider an animal for a breeding program that has not had a breeding clearance examination. Time and again we've found serious congenital heart disease in grand champions! After such a serious investment in time, energy, and money, this is a heartbreaking experience for everyone.
- Results of tests vary with circumstances. Don't bring an animal for either a CSE or BCE that isn't healthy in other regards. A fever, anemia, or pregnancy can result in a substantial heart murmur in an animal with an otherwise normal cardiovascular system.
- If an animal is found to have congenital heart disease, then related animals are suspect genetic carriers! This includes progenitors, siblings, offspring, and other related individuals. Optimally you need to find the source of the abnormality, i.e. the individual(s) originating the defect, and discontinue related individuals from the breeding program.