I can't figure out if this makes me sound stubborn, ignorant, or lucky but I do annual fecals and have never had a heavy problem. Before I continue I should knock on wood... In 15 years I have never wormed a chicken of any age, or treated coops. Our feed medicated feed. I guess as the saying goes - "if it ain't broke I ain't gonna fix it"
Off to finish lighting the fire for the boiler and setting up the cones... it's semi annual butcher day here. Let's hope the weather holds.
I worm as much to prevent as I do treat. I have a semi regular routine. There is a partial rotation here, and I treat before the move. Birds kept in high densities for the area kept without rotation will eventually lead to high loads of any of the parasites.
I worm before they come into lay, before breeding season, and when they molt. This lessens the impact on eating eggs, and this is when the birds are being moved (less the molt). The idea is to have them "clean" before putting them on clean or cleaned ground.
Parasites is something we all have to contend with. It is kind of like fleas with dogs. They are going to get them. We all have to manage the load, and everyone's preferred management style is different. Everyone's scenario is different as well. The pressure from one region to another, and specific location is different. Heck some breeds and strains are more tolerant. Some individuals are.
The raccoons on our sea islands and approximate to our marshes, particularly in the southeastern corner of our state, are rather poor looking and on the small side. It is not diet. They have more access to quality food than anywhere in our state. Not only do they have the food that they have farther in shore, or farther north like yourself, but the marshes are full of food. It is like a buffet for raccoons, all year round. The difference is the parasite load. Everything is in surplus there to include the parasites. Every benefit seams to come at a cost. Anyone that has spent a day and night out in the woods, on these sea islands, in the summer, knows what I am talking about. Bull Island is a magnificent place to visit, but after May, you will have it to yourself. It is literally difficult to tolerate being there. I am talking about the places that are still in a wild state.
My point is that we all have to figure out our own way, and we will all eventually have a problem. Once we have a problem, the load is already established. Then it is a hard cycle to break, unless you have new ground to move them.
That is my view on the subject.