I have the following in my data base -
breedId Species Breed
0 dog Alsatian
1 dog pitbull
2 dog Shetland sheepdog
3
You are not filtering the data in the second drop down list, based on the selection made in the first drop down list (which is what you want).
Also, you need to add the AutoPostBack="True" property to each DropDownList, if you want the changes to be reflected as soon as you change the value of each DropDownList.