At this writing (May 25, 2023), there is one piece of legislation requiring support from horse lovers. Please see Section 2. 118th Congress below.
The following is a historic representation of previous legislative attempts to protect our horses. Thank you.
1. Horse Soring: HPA Rule
URGENT! Contact Agriculture Secretary Vilsack by email at firstname.lastname@example.org OR use Contact My Politician (Vilack’s name is already inserted), using the words “Reinstate the HPA Rule” in the subject line stating:—
“I respectfully request that you immediately reinstate the 2017 Horse Protection Act (HPA) rule promulgated by the U.S. Department of Agriculture (USDA) to end the cruel practice of soring.”
Please feel free to use those exact words. Vilsack is very aware of the HPA Rule and that he is required to take action to restore it. 
2. Horse Soring: PAST Act 2021 (S.2295)
U.S. Senators Mike Crapo (R-Idaho) and Mark Warner (D-Virginia) have again reintroduced the Prevent All Soring Tactics (PAST) Act to protect horses from the abusive show practices. Soring is a process by which horse trainers intentionally apply substances or devices to horses’ limbs to make each step painful and force an exaggerated high-stepping gait rewarded in show rings. Although federal law prohibits soring, a U.S. Department of Agriculture (USDA) Inspector General (IG) report found that some horse trainers continue this inhumane practice.
This Bill has 48 co-sponsors as of this writing. Note: If the Bill becomes law, it will act in concert with a restored HPA Rule (see 1. above). 
To amend the Horse Protection Act to provide increased protection for horses participating in shows, exhibitions, sales, and auctions, and for other purposes.
» 118th Congress 2023-24
• Protecting Horses from Soring Act of 2023 — H.R. 2648. Please contact your elected official in the U.S. House Representative and request co-sponsorship of the Bill and support by voting for its passage.
3. Wild Horses
Contact Interior Secretary Deb Haaland to immediately suspend the Bureau of Land Management Adoption Incentive Program. Tips below.
— What you can say
“It has been documented and confirmed that individuals are adopting federally protected wild horses or burros, then dumping them at kill pens from where they are sent to slaughter, a federal offense. Therefore, I strongly urge you to immediately suspend the BLM’s Adoption Incentive Program.”
Email the DOI at email@example.com or use their online form.
— More on Incentive Program Abuse
To encourage more adopters to give a wild horse or burro a good home, the Bureau of Land Management Adoption Incentive Program provides up to $1,000 to adopt an untrained wild horse or burro from the BLM. Adopters of the abandoned animals must sign a contract promising to protect them from abuse, neglect, or slaughter.
Unsurprisingly, wild horses are tragically ending up in slaughterhouses under this new adoption program.
An investigation by the American Wild Horse Campaign (AWHC) and its coalition partners discovered that groups of related individuals were adopting four horses or burros each (the BLM’s per-adopter limit), then dumping them at kill pens, collecting $30,000 or more in incentive payments and sales fees.
Haaland is proving at the least — to be uninterested, or at the most — hostile regarding America’s wild horses. She admitted at the outset she is maintaining the status quo from the previous Administration in their regard. Haaland is no doubt taking the lead from the Bureau of Land Management. This is an ongoing tragedy. Maybe if we all pull together we can “wake her up”. 
4. Horse Slaughter — H.R.3355
Contact your U.S. Representative requesting co-sponsorship of H.R.3355. As of this writing H.R.3355 has 48 co-sponsors. See all current co-sponsors here »
It is helpful to compose your thoughts and write out what you want to say ahead of time, especially when telephoning. Preparing yourself ahead of your call will make you feel confident, plus you are less apt to leave something out important to you.
— About the Bill
On May 19, 2021, Rep. Janice D. Schakowsky (D-IL-9) introduced H.R.3355 in the 117th U.S. Congress :
“To amend the Horse Protection Act to prohibit the shipping, transporting, moving, delivering, receiving, possessing, purchasing, selling, or donation of horses and other equines to be slaughtered for human consumption, and for other purposes.”
Called the Save America’s Forgotten Equines (SAFE) Act, it would permanently ban horse slaughter in the U.S. and end the export of horses for slaughter. The bill was referred to the House Committee on Energy and Commerce on the date of introduction, May 19, 2021. Rep. Vern Buchanan [R-FL-16] is originating co-sponsor.
• Find your Representative here » See if your Representative has already co-sponsored here »
• Track Congressional actions here.
Introductory Statements by Schakowsky and Buchanan
“For centuries, horses have embodied the spirit of American freedom and pride. They are our companions, work partners, entertainers, and athletes. With such a special place in our nation’s history it’s beyond time that we end the brutal practice of slaughtering these majestic creatures as food for humans. I am proud to reintroduce the SAFE Act with Congressman Buchanan and offer legislation that will finally close a loophole to end the slaughter of American horses for human consumption, both domestically and abroad,” said Congresswoman Schakowsky.
“The slaughter of horses for human consumption is a barbaric practice that has no place in America,” Congressman Buchanan said. “I look forward to continuing to lead the effort with Congresswoman Schakowsky to ban domestic horse slaughter and end the export of horses abroad for the same purpose.” 
Thank you everyone. Thank you for giving your voices to our beloved horses.
• Congress.gov »
• Find Your U.S. Representative (you have 1). You may need your 9 digit zip code) »
• Find Your U.S. Senators (you have 2) »
• U.S. Capitol Switchboard: (202) 224-3121
Note: You will need your lawmaker’s name before dialling. They will not look it up for you.
118th Congress of the United States
The 118th United States Congress is the current meeting of the legislative branch of the United States federal government, composed of the Senate and the House of Representatives.
It is comprised of the following Members: 100 senators; 435 representatives; 6 non-voting delegates.