It was difficult at best to come up with a shrub that met 6 criteria. The best match I could come up with for you is Aruncus dioicus (Goat's Beard). It is said to do well in full shade and in windy areas, was listed on many sites as "pet safe" (you will want to confirm the toxicity), grows up to 6 feet, is flowering and is designated for USDA plant hardiness zones 3-7 (you are 5a).
For more information on aruncus dioicus, please visit the following link:
Here is where I got started in my search - the ASPCA has a searchable database of plants where you can determine if something is pet safe: