@Jennifer1961
Unfortunately there's not a "pet fee" option but maybe someday there will be! Here's how I handle getting the pet fee....
After experimenting with several different options, I've found the best way for me is to request the pet fee via the Resolution Center prior to arrival. When I send the request, I let the guests know the pet fee must be paid prior to check-in, or the pet will not be allowed on the property.
If they have not paid the pet fee within 2 days of arrival, I send a reminder.
Early on, I made the mistake of not insisting on the pet fee prior to arrival, and twice, it never got paid. So, now I am VERY firm that the pet fee must be paid in advance, or that pet will not be allowed on the property. Thankfully, I haven't had to do that and everyone pays up!
As for how do you know if the person is bringing a dog? Most people volunteer this information but make it very clear in your listing that you need to know in advance if the guest is bringing a pet. (you can view my listing to see how I mention it in several areas!)
You can also set up your "pre-booking" message to include asking if they are bringing any pets.