Property to Rent

Hi. I am being transferred over to our US company, from London to Ashburn. We looking for a rental single family home in the area. Our problem is that we have owned our own homes for years and both being animal lovers, we have 2 Border Collies (one is Search and Rescue trained) and 3 cats. Our animals are all extremely well trained, 100% house trained. As my wife is a veterinary technician, we have trained our pets well. However we appreciate this is more animals than most land lords would normally allow. Has anyone got any suggestions in trying to find a home for our family (we also have a 17 month old boy). Looking for 3+ Rooms, 2+ Bathrooms. We would also considering a small farm as I am sure my wife would love to have a horse again.