My understanding is that horse paste is dosed at .2mg/kg, so if your horse weights 80kg and it takes an 80 kg amount of paste(almost 1/8 of the tube{The tube I am referencing is for a 680kg/1500pound horse}) you get .2mg/kg into your horses system.
2mg is 10X .2mg, so your 80kg horse would need to take ten times the .2mg/kg dose or an amount for an 800kg horse to get a 2mg/kg of body weight dose. That would be almost 1.2 tubes of horse paste.
Link to Bix Weir youtube channel. https://www.youtube.com/@RoadtoRoota
yes it is ddl. Gangs of New York is the movie.