Is it possible to use events when useing Implements

Say for example i have an interface for Animals
Some basic functions in it like eat,sleep etc
Now i want some events for the animals like, Tired/Angry etc

Now i have a class called Dog
it implements Animal so i can use the functions and sub etc, but now i want the dog to raise the events that it is tired, however it seems i cannont get the event to work.

When i add the event only to the Interface(Animal) then

Private Withevents CAnminal as IAnimal
Set CAnimal = New CDog

i get an error "Class or object does not support the set of events."
Same thing happens if i just copy the event to the Dog class


Is there anyway of doing this? (slimey hacks are welcome =])