What can you do if your swimming pool is foggy or milky looking?

I too had milky water in my pool. I also have a chocolate lab dog who loves the water. I found that with allowing the dog to swim would turn the water milky and that a "slime" would develop on my filter and in my filter housing. I can't deny the dog but I can limit the number of swims. My pool is small so it's not hard for me to fix. I change the filter or clean it real well every day for a couple of days following one of her swims. I also heavily "shock" the water at the end of the day for 2 days after her swim. If the cause of you milky water is a 4 legged friend, this has worked for me.

New answer::

Ah, yuck! Do you realize the germs on a dogs body. Milky and slime more YUCK! Extend the filter run time if you insist on having a dog swim in your pool. As a pool service person, I wouldn't even put my toe in the pool under those conditions. Milky water is caused by many things but lack of filtration is one and lack of a sanitizer is another. You are subjecting yourself to a multitude of germs and bacteria. Diarrhea, e-coli are but a few found in pools. Oh, horrors of horrors!