The campaign, by dairy awareness nonprofit Be Vegan, featured 10m² posters on trams in Ghent and Antwerp.
The posters carried the slogan 'Milk is deadly. For 150.000 Belgian calves per year', in reference to the male calves who are killed by the industry.
The campaign was slated to run for four weeks, but transportation company De Lijn removed it after just three days.
According to Be Vegan, the removal was prompted by 'a storm of angry and intimidating emails and phone calls directed to De Lijn' from dairy industry advocates.
"After talking to the direction of De Lijn we respect their decision to stop the campaign, mostly because the situation had become unbearable for them," BE Vegan spokesperson Bram Bruyland said in a statement sent to Plant Based News.
"Negative backlash from the dairy industry was something we had taken into account, but we did not expect this kind of intimidation. Apparently, the dairy industry wants to hide the facts from the public.
"It is not our intention to shame farmers for how they do their work; we simply want to stress that behind every dairy product, there is always animal suffering involved. As consumers, we have a choice to buy plant-based products instead."
PBN has contacted De Lijn for comment.