In 2009, the Frolicking Horse Family Gift Set #7212, included the mare and foal from the #7038 veterinarian set, along with a stallion. Was available at Big Lots, and maybe other similar stores.
Side note: The only difference I can see from sets #7038 and #7212, is that set #7212 has a much longer mane and forelock, and the blaze edges are more crisp.