LOS ANGELES – The busiest day of the summer at most animal shelters around the country is July 5.

Shelters are “absolutely chock full of terrified dogs on the day after the Fourth of July,” said Dr. Kate F. Hurley, director of the Koret Shelter Medicine Program at the University of California at Davis Center for Companion Animal Health.

When she was an animal control officer, she saw dogs “jump through plate glass windows, they were so freaked out.” Severely stressed dogs may even need tranquilizers to get through the night, she said.