The woman was driving by a vigil at Fearmans Pork Slaughterhouse in Burlington, Ontario, and responded with nearly a minute of honking when she was held up behind a transport truck stopped by activists.
A few activists recorded the incident, including Abby McCuaig, who shared her video on Twitter.
As part of the demonstration, activists stop trucks carrying pigs headed to slaughter in an attempt to give them water and comfort them prior to their deaths.
A two-minute timer is displayed, along with a sign informing drivers of the practice.
McCuaig told Plant Based News that it was difficult to communicate with the woman because of the honking.
She said: "A few activists attempted to talk to her to calm her down. Her honking didn't really bother us but it was clearly affecting the animals and that was our main concern."
One Twitter user who commented on the video wrote: "I hope she realizes that what she did was not only disrespectful but also heartless."
'I'm a vegetarian'
Despite disrupting the vigil, the woman reportedly claimed that she doesn't eat animals.
McCuaig said: "When we said it’s not about us, it's about the animals and we are trying to offer them love in their final moments, she said 'I'm vegetarian I get it' but continued to honk and shake her head."
She added that 10,000 pigs between four and six months old are killed at the facility every day - and that vigils are held there on a weekly basis.