I calculated my dosages of the Ivermectin paste as detailed from several learned sources on the net, at: 0.2mg per kg/body weight; or, 0.09mg per #. This is close to the dosage when using the plunger guide. Rule of thumb: each notch on the guide is the dosage for 50lbs weight. I have read Ivermectin is very forgiving as long as you don’t consume a whole 1250# tube of paste at one sitting and you are reasonably mindful of your dosages. But then, I’m not a doctor nor a veterinarian - so proceed at your own risk.