I'm also not sure, so I set off to do a little research on the question, and found that if Borates are in the water the water is a lot more potentially toxic than if it is merely chlorine. Here is the article that talks about that.
http://www.troublefreepool.com/threads/19516-Dogs-drinking-pool-water
I could be 100% off base in my assumption, and if so I apologize and hopefully someone will correct me if I'm wrong.
By combining what I've learned here at TFP, with my medical degree knowledge here are my thoughts. With everything above being said, and knowing the high FC levels may not be potentially harmful/fatal to the wildlife/pets if consumed in small amounts. Like with anything, they can always consume too much of a good thing, including plan ole tap water which can also harm/kill a person/animal if too much is consumed at any given time.
Then you have to still ask yourself this question: How much is too much? A 120 lb deer may be able to consume 2 cups of high FC water in a single setting without any side effects at all, yet Mr. Opossum comes in, and drinks himself 1 cup of high FC water twice in the same day then becomes ill from the amount.
IMO since we can not really determine how much is too much, nor force them to limit their daily intake I would suggest keeping the pool covered the entire during the SLAM process, and sit the Wildlife a Plastic Kiddy Pool off to the side refilling it daily with fresh low chlorine tap water. That way you can get your Slam done correctly, and still safely water the Wild animals who have come to rely upon you for their daily drinking water.
LOL I know this didn't exactly answer your question, but IMO it is always better to be safe than sorry. I'm really curious to read all the other comments that arise from this post. Have a nice night?