Amelogenesis Imperfecta (AI) is an inherited disease of the teeth affecting Italian greyhounds. Signs of disease are often noticed when baby teeth erupt. Affected dogs are unable to develop normal tooth enamel resulting in misshaped teeth with rough, irregular surfaces and gray or brown spotting. Affected permanent teeth are often smaller and more pointed than normal teeth. Premature, excessive enamel wear results in the appearance of larger than normal gaps between the teeth of affected dogs, even at an early age. Despite enamel defects, affected dogs are not at increased risk for periodontal disease and only rarely develop dental cavities or broken teeth.
Breed-Specific Information for the Italian Greyhound
The Mutation of the ENAM gene associated with AI has been identified in the Italian greyhound. Though the frequency in the overall Italian greyhound population is unknown, in one study of 208 Italian greyhounds tested from a population from the US and Canada, 30.3% were carriers of the mutation and 13.8% were affected.
Genetic testing of the ENAM gene in Italian greyhounds will reliably determine whether a dog is a genetic Carrier of AI. AI is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the ENAM gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Italian greyhounds that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
Gandolfi B, Liu H, Griffioen L, Pedersen NC. Simple recessive mutation in ENAM is associated with amelogenesis imperfecta in Italian greyhounds. Anim Genet. 2013 Aug;44(5):569-78.