But, it's a tough situation.

Usually people have their dogs with them because they love them so much, explains Church. Yet, if it is an incredibly hot day, and the animal has been left in the car, it could be considered a crime, she said.

"You do have to look at it on a case-by-case situation," Green said.

If the owners have their dog in the car during the spring, with the windows cracked, it may not be found to be a violation, he said.

Best and worst states

Every year, the Animal Legal Defense Fund publishes a report that surveys animal protections laws of all the U.S. states and territories.

Each jurisdiction receives a raw score that's based on 42 study questions covering 15 different animal protection law categories.

It then ranks the jurisdictions and lists the "Best Five" and "Worst Five" states overall.

One of the biggest factors ALDF looks at is whether a state treats animal cruelty as a felony, Green said.

South Dakota doesn't have any felony animal cruelty laws, so it's naturally on the list of worst states.

On the other side of the coin, Illinois has consistently ranked at the top of the list, having the strongest animal protection laws in the country, notes Green.

In 2012, the five states with the best animal protection laws were: 1. Illinois, 2. Maine, 3. California, 4. Michigan and 5. Oregon

The five states with the worst animal protections laws were: 1. New Mexico, 2. South Dakota, 3. Iowa, 4. North Dakota and 5. Kentucky

North Dakota recently added a felony animal abuse charge, but Green said it'll likely make the "Worst Five" this year as well.

"There's always room for improvement, even if a state already treats animal cruelty as a felony," Green said.