Running for deer life

Quite some attraction in the park today. It took me a while to understand what was happening...
A dog managed to enter the deers' enclosed area, which they share with a few ostriches.
The dog purchased the ostriches and the deer were so frightened they kept running back and forth in a tight pack.
One ostrich nearly got caught (pfiou!), then the dog was finally cornered. Everyone applauded, like it was the end of a planned demonstration! I continued to shoot pictures, the deer were all in one corner of the field, frozen like statues, looking in the direction of the final action. I hope none of them had a heart attack! Poor things, they looked so scared!