Born With Missing Teeth
Congenital Defect among Australian Shepherds
- Congenital Palatal Defect
- Increasing problem after 1980s
- Shorter muzzles became more popular
- AKC agreed - changing description to state “muzzle is equal to or slightly shorter than the back skull.”
- Past few generations selection for shorter muzzles have increased frequency of missing teeth
What do we know?
- There is not a lot known about the specifics of inheritance.
- Due to complexity of the jaw and the fact that the mode of inheritance is different among breeds, missing teeth is a polygenic trait.
- Because missing teeth is a polygenic trait, its harder to determine what is being inherited. To decrease the frequency, Australian Shepherds with missing teeth are not bred with others that also have missing teeth. If the amount of missing teeth and presence of other dental defects, the dog is not used for breeding purposes.
"Missing Teeth." Australian Shepherd Health Genetics Institute. 1 Mar. 2013. Web. <http://www.ashgi.org/home-page/genetics-info/teeth-and-jaws/missing-teeth>.
Sharp, C.A. "A Close Look at Canine Dentition." Aussie Times. Australian Shepherd Club of America, Inc., 1 July 2002. Web. <http://www.ashgi.org/home-page/genetics-info/teeth-and-jaws/so-bite-me-a-close-look-at-canine-dentition>.
Sharp, C.A. "The Backyard Geneticist." The Institute of Canine Biology. Australian Shepherd Health & Genetics Institute, Inc., 1 Jan. 2014. Web. <http://www.instituteofcaninebiology.org/uploads/1/9/6/9/19691109/ca_sharp_-_backyard_geneticist.pdf>.