What pet fees are typical?

[Michael Maliszesky]

I'm currently setting up the terms for the rental agreement for a house. I've never delt with pet fees before, but my potential tenants have 2 dogs. I know some people charge pet fees, additional deposits, and additional rent. 

I'm curious to know what fees/rents/deposits other landlords/property-managers charge. 

(BTW it is a 4 bedroom house in Virginia Beach)