A variety of structural and functional defects have been described in animals. When a problem is present at birth, it's called congenital. If it's passed through family lines, it's inherited.
These kinds of issues can start during early development, before animals are born. Some developmental problems cause pregnancy loss or stillbirth. Sometimes an animal is born that can't survive, or an animal does survive but has a defect.
Many congenital and inherited defects in dogs are possible, but common ones include:
nervous system defects
digestive system defects
heart defects
muscle and bone defects
testicles that don't drop into the scrotum
abnormal joint development (hip or elbow dysplasia)
How sensitive developing animals are to different causes of defects depends on their species and their mother's stage of pregnancy. Sensitivity usually decreases as the pregnancy continues.
How often individual defects occur depends on breed, location, season, and environment.
Many congenital problems have no clearly known cause. Others result from genetic factors, environment, or both together.
What Genetic Factors Can Affect Puppies?
Inherited problems follow certain patterns based on the DNA (genetic material) contained in an animal's genes that determine how the animal develops. Abnormal genes can be inherited from the mother, the father, or both parents. Some genetic problems in puppies occur when only one parent contributes an abnormal gene (dominant genes), while others occur only when both parents contribute abnormal genes (recessive genes). In addition, some genetic problems in puppies affect males and females differently (sex-linked genes).
Defects in genes can cause problems in developing puppies, leading to missing or weak enzymes involved in metabolism, infertility, abnormal growth, miscarriage, or small litter sizes. Viruses, certain medications, and exposure to radiation can also damage genes and ultimately lead to developmental problems in puppies.
What Environmental Factors Can Affect Puppies?
Developmental defects in puppies caused by environmental factors include:
Toxic plants
Viral infections during pregnancy
Certain drugs
Mineral or vitamin shortages
Poor nutrition
Physical stresses (exposure to radiation, high body temperature, crowding within the uterus during pregnancy)
These causes can be hard to identify and vary by season, stress, or the mother’s health. These kinds of problems don't follow the pattern of family inheritance.
For More Information
Also see professional content regarding congenital and inherited disorders.
