A 4 pound bird would get 1 ml which is roughly 1/5 of a tsp. 5 ml is 1 tsp. Most pharmacies will give or sell a 1 or 5 ml needle-less syringe if you ask for it. It can help with dosages. Feed stores sell 5-10 and larger ones.
SafeGuard (fenbendazole) liquid goat wormer will settle out in water, so it is best to give it to each hen orally or in a small bit of food. Dosage is 0.23 or 1/4 ml per pound of weight given orally for 5 consecutive days to get the more severe worms such as gapeworm and capillary worm. If you...