Electronic collars are no longer considered leashes and pet owners are vulnerable to fines for leaving their animals confined to cars on hot days, the city council decided Saturday at a public hearing.

Dog owners already were required to curb their canines, but what constituted a physical leash was a bit murky until Saturday. The council did not outlaw electronic collars but decided that, by itself, the technology is not a sufficient form of physical restraint in public.

Violators could face a $100 fine, according to the ordinance.

“This [ordinance] is both about animal safety and public safety … this is one of those strange situations where technology probably … hinders you guys from being able to do your job,” Vice Mayor Kerry Donley told Alexandria animal control officers.

Officers were having trouble enforcing leash laws because electronic collars are not obvious restraints, leading to confusion among pet owners and the public.

The issue is not just about safety, said Alexandria Animal Control Director Mary Beth Mount. It’s also social.

“We [live in] a huge melting pot … We have people in our jurisdiction from a different upbringing that don’t revere pets the way that we do,” Mount said. “So in a way it’s very unfair to the citizens to feel they have to protect themselves, even if Fluffy is a very nice dog.”

The council also made it illegal to confine pets in vehicles with no open windows or air conditioning on hot days — when the outside temperature is 70 degrees or higher. A vehicle’s internal temperature must be no hotter than 80 degrees, according to the ordinance.

Animal control officers received 103 calls about pets left unattended in cars between May and September. The law gives officers authority to “remove any animal that is suffering from heat stress” and provide veterinary care.

Donley called it a “no-brainer” and officials agreed it promotes Alexandria as a pet-friendly place.