Dock Dog $20.00 Inside Message Blank Packages of Heartstrings® cards are shrink-wrapped and sold in sets of 10 cards with envelopes. The actual card size is 4 1/4" x 5 1/2". Dock Dog quantity Add to cart SKU: dock dog. Category: Pets. Related Products A Friend Knows $20.00 Cat & Snow $20.00 Fetch Your Sticks $20.00 Chews Gifts Carefully $20.00