The ground is covered in wood chips, which can become dusty on dry days. On hot days, there is water available for Fido to quench his thirst and there are shady areas under the trees, which are located primarily around the perimeter. Temporary pop up coverings have been used in the park to add more shade. There are benches and chairs for you when your legs get tired. Garbage pails are around, but bring your own bags to dispose of any poop.
As much as you might want to take Fido exploring the rest of the park on-leash, Nassau County does not allow dogs in county parks except in doggie designated areas, even if they're on a leash. No matter where you are, make sure your dog is wearing his collar with ID tag and is up to date on his vaccinations. He should be able to respond to your call. If you've never taken him to a dog park, you should go when the park isn't busy. Christopher Morley Dog Park is busiest in the afternoon.
Also, from Memorial Day to Labor Day, you need to obtain a Leisure Pass (for Nassau County residents only), which costs $30 and can be purchased at several parks, including Christopher Morley. You can also contact contact the Nassau County Department of Parks, Recreation, and Museums to inquire about getting a pass. This pass will also get you into other Nassau County parks and discounts to paid park features.