There is no argument about treating one or two birds or a whole flock for tapeworms.
Take a look at the tapeworm lifecycle and then take a look at the roundworm lifecycle and you'll see why.
I completely understand if owners want to worm a whole flock for tapeworms. Owners dont have the time to follow a bunch of chickens around on their property looking at chicken poop to see if there's tapeworm segments in the poop. It makes sense to worm the whole flock, I've done it.
However, for small flock owners, or if a few birds are penned in each chicken pen, it would be easy to see which bird pooped segments. Then treat that particular bird accordingly. The others wouldnt need treatment.
I think there is argument for treating a whole flock versus just individual birds for tapeworm. I’ll go into my reasoning because I’m passionate about pest/parasite control and I believe the more understanding about the complexities of these issues can help people make the best choices for them. I just want to preface it by saying I’m not trying to be argumentative or discount anything you’ve said.
If you have a bird or several birds infected with tapeworm, pooping out proglottids that contain however many thousands of eggs that then contaminate the surrounding environment… you’re going to end up with a greater environmental load of tapeworm and greater risk of more than one bird becoming infected.
The longer tapeworm goes unnoticed in a flock the more proglottids and eggs will be released to be eaten by transient insects… and the more prevalent it will become in the environment — especially so if you compost your chicken’s poop and then put it back out in the garden (unless you are doing a hot compost).
Then consider other factors that may increase or decrease the population in the environment. Time of year / location / temperature and humidity / does the ground dry out? / is the ground exposed to sun and UV or mostly shaded? / what insects are prevalent? / flock size / size of area they are kept on / other birds e.g. neighbouring flocks and wild birds. There are so many variables.
Another consideration is that it takes at least two weeks from when the bird eats the infected bug to having a mature tapeworm shedding proglottids. You see one chicken pooping out segments but you don’t see inside whichever other chickens may have picked up tapeworm that haven’t quite reached maturity.
Yes there is a difference of life cycle between tapeworms and other worms like roundworms. Effective pest/parasite control will look at the life cycle but also the variables, with the aim of interrupting the life cycle to control or eliminate infestation/infection. In the case of recurrent tapeworm and high environmental load, breaking the life cycle as it occurs in the chickens themselves is going to be the most accessible option.
It’s entirely possible that one can find tapeworm segments in one bird’s droppings and it’s legitimately a once-off from some random bug and you treat that bird and then it’s no longer an issue and it never comes back. Especially if you catch it early. Especially if you live or keep your chickens somewhere unfavourable to worms. But I have seen a lot of threads here where people battle recurrent tapeworm and that’s not just random luck of which hen ate which insect — that’s a high environmental load causing greater rates of infection. Worming the whole flock on a schedule becomes a conscious choice as a way to manage and reduce that environmental load over time, not just a matter of convenience.
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