It said it welcomed the new policy of the Canadian Food Inspection Agency (CFIA) regarding health and medical-treatment declarations, but said it remained cautious about its actual implementation and impact.
The institute labelled the industry as cruel. It accused industry backers of hiring lobbyists and public relations firms in its efforts to overturn laws in favour of slaughter.
It said it would closely watch the implementation of the new Canadian policy and diligently follow the reactions of the horse slaughter industry.
"While the announcement by the CFIA does nothing to end the abuses of horse slaughter itself, it will certainly be a blow to the industry and that is a step in the right direction," said Chris Heyde, deputy director of government and legal affairs for the institute.
"My big concern is what killer-buyers will do to the horses they will have to warehouse for six months.
"We will all have to wait and see if the [Canadian] policy is actually implemented as announced and what the horse slaughter industry will do to address the new requirements.
"The policy, if followed, should diminish the US and Canadian horse slaughter industry."
However, he warned that if the regulations forced kill buyers to warehouse horses for six months to meet drug withholding periods, it could come at great cost to the horses.
"In an effort to keep costs down, we can be certain little if any care will be given to the horses," Heyde warned.
"This could lead to tremendous suffering and abuse before being sent to slaughter.
"We must remain mindful that killer-buyers may still choose to simply ship American horses to Mexico, which has not yet announced a policy handling health concerns raised by the European Union.
"Numerous investigations have exposed the unspeakably inhumane methods of transportation and slaughter practices ongoing in Mexico.
"Horse slaughter lobbyists have recently tried to take a humane tone to their defence of slaughter that nobody buys. However, if they have any compassion, now is the time to advocate for an end to slaughter and passage of the federal Prevention of Equine Cruelty Act," Heyde said.
"This is the only way we can ensure our horses are protected from abuse in feedlots, during transport and at the slaughterhouse."