What Is Congenital?
A congenital condition is one that is present at birth, whether inherited genetically or caused by developmental problems during pregnancy. Congenital does not always mean genetic — environmental factors during fetal development can also cause congenital defects. Examples in pets include congenital heart defects, cleft palates, and some joint abnormalities.
Understanding Congenital
The term congenital describes timing (present at birth), while the terms hereditary or genetic describe causation (passed through genes). These concepts overlap frequently but are not the same thing. A puppy born with a congenital heart defect may have inherited the gene predisposing it to that defect, or the defect may have resulted from a problem during fetal development unrelated to genetics.
Congenital conditions become apparent at different stages of an animal's life. Some are obvious immediately at birth (cleft palate). Others are detected at a puppy or kitten's first examination. Some, like certain heart defects, are discovered only when symptoms appear months later as the animal places more demands on an abnormal structure.
Many breed health testing programmes focus specifically on identifying genetic carriers of congenital conditions to prevent their propagation through selective breeding. Hip dysplasia (structurally abnormal hip joints), patent ductus arteriosus (a fetal blood vessel that fails to close after birth), and portosystemic liver shunts are among the most clinically important congenital conditions in companion animals.