Breeders who sell pets online will now be required to get a license.
The human society said it is a victory for small animals as the new law will extend federal oversight to thousands of puppy mills that do business online.
Online breeders have avoided regulation previously under a loophole that allowed them to claim status as a retail store.
"If you are selling puppies online, you better get licensed and you may be subject to an inspection, so it puts them on notice now that it's not going to be business as usual," said Carl Arky, Humane Society of Utah.
An agriculture official said with internet breeders, inspectors and buyers never see where the animals are coming from and what their living conditions are like and this law will change that.
The new regulation will let buyers see the animals before they buy them. It also gives inspectors the authority to make sure breeders are taking proper care of their animals.
A spokesperson from the Department of Agriculture said the licenses will cost about $750. The law will apply to breeders who work with dogs, cats and rabbits. Sellers who have less than four breeding females will be exempt.
Enforcement of the law, whether on a state or federal level, is still unclear.