Anodontia

A genetic disorder characterized by the absence of all teeth due to a failure of development, anodontia is quite rare and is mostly seen in animals affected with other hereditary or genetic conditions. Hypodontia is genetic in origin and usually involves the absence of from 1 to 6 teeth and is also a result of failure of development. Oligodontia is a condition in which more than six teeth are missing. In hypodontia mainly cosmetic, differentiation between possible hereditary and proven traumatic causes is important for breeding dogs.

Both anodontia and hypodontia are hereditary and are often associated with ectodermal dysplasia seen in hairless and some other breeds. Ectodermal dysplasia is characterized by complete or partial absence of sweat glands, sparse hair growth, absent or deformed peg teeth, sparse sebaceous glands, occasional absence of salivary and lacrimal glands, scanty mucous glands and deficient eyelashes. In some cases, anodontia and oligondontia occur with no apparent congenital or systemic disease.

Breed Prodisposition to Oligodontia

Oligodontia is particularly common in brachycephalic breeds (dogs with shortened muzzles) and may be symmetrical and asymmetrical. Among breeds, oligodontia is most frequently found among Collie, German Shepherd, Poodle and German Hunting Terrier. The condition affects the first and third premolar of the upper jaw, followed by the first and second premolar of the lower jaw.

Hypodontia

Missing teeth (hypodontia) are most commonly seen in small dog breeds, and in some larger breeds can be considered a serious fault. Permanent teeth are more frequently missing, and if a deciduous tooth is genetically not present, the permanent analog that arises from the primary will also be absent.

In Kerry Blue Terrier dogs hypodontia and oligodontia are thought to be inherited which requires comprehensive study of their genetic control.

References

1. Inheritance of hypodontia in Kerry Blue Terrier dogs Aksenovich TI, Zorkaltsov IV, Aulchenko IuS, Kniazev SP, Kulikova AV. In: Genetika. 2004 May;40(5):658-66.
2. Robert B. Wiggs, Heidi B. Lobprise. Veterinary Dentistry.
3. Radiological analysis of oligodontia among dogs in Croatia. V Butkovic. In: VETERINARSKI ARHIV 71 (2), 57-63, 2001
4. Cecilia Gorrel. Veterinary dentistry for the general practitioner.
5. Robert B. Wiggs, Heidi B. Lobprise. Veterinary Dentistry.