Hello,
no, it's not conclusive that if one goat has worms that all other goats have them, too or have them in the same amount. There are always some goats in a herd that are more prone to parasitic infections than others. Often they have other health issues going on, too.
As for fecal testing: lung worms can't be seen with regular flotation fecal tests. They need a test that takes several days to have the worm larvae hatch and if you haven't requested that test, as well, you won't know if your goats have lung worms or not.
And the dewormer you used is not effective against lung worms. You need to use ivermectin, cydectin or doramectin
no, it's not conclusive that if one goat has worms that all other goats have them, too or have them in the same amount. There are always some goats in a herd that are more prone to parasitic infections than others. Often they have other health issues going on, too.
As for fecal testing: lung worms can't be seen with regular flotation fecal tests. They need a test that takes several days to have the worm larvae hatch and if you haven't requested that test, as well, you won't know if your goats have lung worms or not.
And the dewormer you used is not effective against lung worms. You need to use ivermectin, cydectin or doramectin