Pond x Dog

So like anyone else here, I'm a pond fan. A big one.
I have plenty of space here at my new house (5 acres) and my husband and I have different ideas about having a pond. I want something right now even if it's small, our budget is pretty, pretty tight once we just bought the house. And he wants to wait until we can have a big pond with an island in the center and, of course, a brick bbq on it.
Finally I convinced him to make the small one for now. And I even thought about digging a hole, put some 6 mil, use a pump that came in a font with the house and call it a pond.
BUT we have a problem, it's black and it's called a labrador retriever who loves water, or just Boris. The pond will be his next house, I know that for sure, so the 6 mil is out of question.
I have a few questions:
1) What is safer to buy, a 45mil pond liner or a rigid, preformed liner? I know with the 45 mil I can shape it as whatever I want and it's cheaper, but would it be resistant enough with a lab jumping in it all the time?
2) If I use 45 mil, should I make it deep enough so he would be swimming and not stepping or not so deep so he has firm ground and wouldn't scratching it while swimming?
3) What minimum size is ideal for the fishes to share the pond with Boris? I'll make sure they have places to hide in, like rocks and plants.
4) What about racoons? Will they eat the fishes? If yes, how deep should I make it?

Thanks in advance for any help!!!

acbunker

The first mistake I made 40 years ago was to build a 6 mil pond with a black Lab as a pet. The second was to add a mallard duck. But that is another story...

If you cannot keep the dog out of the pond then I suggest building an aviary around it to also keep out the GBH, Egrets, raccoons and your dog. If you don't, you will regret having gone through all that work, only to have Fido destroy it.