Last Friday, Utah Gov. Spencer Cox signed a bill to end the use of gas chambers for euthanasia of cats and dogs, leaving just two states in the U.S.—Missouri and Wyoming—that continue to use this cruel and archaic method. Today, only three known and active gas chambers are used for companion animals throughout the entire country.

Although gas chambers were once considered a humane euthanasia technique, we know better now. Death in a gas chamber can be terrifying and slow. The animals are placed in a small, dark box and might remain conscious for several minutes, trying desperately to find a way out. They sometimes convulse before losing consciousness, and death can be especially slow to come for animals who are very young, very old or sick.

There are so many reasons to end this practice: Not only are gas chambers cruel for animals, but they also endanger shelter staff with the potential for injury, including accidental gas inhalation, and they have been condemned by the Humane Society Veterinary Medical Association, the National Animal Care and Control Association and nearly every other national animal welfare organization.

Moreover, gas chambers are more costly than the humane alternative, euthanasia by injection. Since 2013, as part of our efforts to dismantle every gas chamber in the country, we have provided grants to shelters and municipalities to transition to humane euthanasia methods. We have collaborated with local leaders and animal care professionals to provide support and education, and we’ve pressed for the passage of laws in states with no active chambers to seal their fate. In January of this year, Ohio Gov. Mike Dewine signed legislation prohibiting the use of gas to euthanize companion animals. Until 2021, Ohio had an active chamber but discontinued its use after sustained pressure. The momentum is on our side to end this practice for good.

In Utah, we spent nine years working on legislation to eliminate the chamber. Thanks to Sen. Mike McKell (R-Spanish Fork) this is the year the fight was won. Emmy award-winning actor Katherine Heigl championed this issue with us, working with our Utah state director, Sundays Hunt, and our lobbyist, Steve Hiatt. Hunt—who passionately led the charge since 2014—shared her thoughts on the win: “This victory is a testament to our years of constant, steady work educating Utahans, bringing together powerful voices like Senator Michael McKell and Katherine Heigl, and never giving up this fight for our state companion animals that deserve humane treatment throughout their lives and certainly at the end.”

Today, 29 states have partial or full gas chamber bans on the books. Lawmakers in Missouri (which has one active gas chamber for cats and dogs) are considering similar legislation, and Rep. Adam Schwadron (R-St. Charles) has introduced a similar bill. We worked in Wyoming this legislative session to introduce a bill, but no animal champion has offered to sponsor it.

Honoring companion animals should come with a commitment to ensure that they are treated with compassion during every stage of their lives. While we recognize that there will always be a need to end the suffering of animals who are experiencing untreatable and severe conditions, we believe humans have an obligation to offer animals a painless death, not the horror of a gas chamber.

We congratulate Utah on taking this important step to eliminate this practice, and we won’t rest until all gas chambers are closed down. There just isn’t a place for them in the humane world we are trying to create.

Follow Kitty Block on Twitter @HSUSKittyBlock.