If it is tapeworms, keep in mind a few things.
The Equimax medication that @Texas Kiki posted, is an excellent dewormer. Just be aware that it has not been approved in the US for use in laying hens. Many people here feel comfortable using it "off-label" for chickens, but discard the eggs for 14 days after treatment.
Second, tapeworms are spread through insects. Basically your hens poops out the white tapeworm segments, an insect eats the segments and becomes a carrier. Your hen then gets tapeworms from eating the insect -- typically beetles, ants or flies. The de-wormer you give your chicken will kill the existing tapeworms in your chicken, but it will not prevent your chicken from getting new tapeworms when it eats another insect. I don't know how you keep your chickens, but after you dose them, you may want to move them to fresh ground and /or try control the insect population.
The Equimax medication that @Texas Kiki posted, is an excellent dewormer. Just be aware that it has not been approved in the US for use in laying hens. Many people here feel comfortable using it "off-label" for chickens, but discard the eggs for 14 days after treatment.
Second, tapeworms are spread through insects. Basically your hens poops out the white tapeworm segments, an insect eats the segments and becomes a carrier. Your hen then gets tapeworms from eating the insect -- typically beetles, ants or flies. The de-wormer you give your chicken will kill the existing tapeworms in your chicken, but it will not prevent your chicken from getting new tapeworms when it eats another insect. I don't know how you keep your chickens, but after you dose them, you may want to move them to fresh ground and /or try control the insect population.