To remove parasites from the body, the biological differences between worm and mammal are exploited. In the case of members of the roundworm family (the ascarid worms), the parasitic worm is attached to the host's intestine by its tiny teeth and/or suckers.

Pyrantel acts as a neuromuscular blocker so that the parasite relaxes its grip, effectively paralyzing the worm so that it loses its attachment.

The worm is then passed with the feces into the cold, cruel world.

Outside of the host's protective body, the worm soon dies. Because the medication is absorbed poorly from the host's intestine, the host is completely unaffected by the paralysis effect. It also helps that the host is substantially larger than the parasite, thus the small amounts of medication needed to remove parasites are not of concern to the mammal host.

Pyrantel pamoate is usually dosed in dogs at 2.5 to 5 mg per pound (5 to 10 mg/kg) once, repeated in three weeks. Each ml contains 4.54mg

Example 10 lbs dog or cat 2.5 x 10lbs = 25mg or 5 ml repeat treatment