Answer:
Small teeth will be missing.
Step-by-step explanation:
As seen from the information of the question, that dogs having medium and long teeth will not carry any alleles for small teeth. So, if a certain viral disease eradicates all the dogs with small teeth, there will be no organisms left to carry genes for this trait. Over time, the medium teeth dogs and long teeth dogs will be more adapted to the environment. Hence, after 10 generations no small teeth dogs will be seen.