The medications will not "prevent" parasites, they will treat them if they have them. Depending on what parasite you may be dealing with, you will often never see anything in droppings, they live their entire life cycle inside the bird, and are digested when they die. If it's possible to get a fecal float test done (same test for all species, some vets won't do for a chicken) that is the best way to know for sure. With a heavy load of parasites you may occasionally see a roundworm expelled in droppings or tapeworm segments, usually nothing else, and most of the time you see nothing at all except maybe runny droppings, weight loss, listlessness, reduced laying.
An inexpensive digital kitchen scale works well for getting weights. I just put a light plastic plate on it, zero it, and then set the chicken on it.
If you can't get a fecal test done, then I would worm and see if you get improvement. If you do, then that is some small confirmation that it could be the problem. Every flock is different, every environment is different. For some people worming once or twice a year may be all that is needed to keep them healthy. Some flocks may need it more often. I have a very parasite heavy environment (roundworm in my case) and have to worm every 3-4 months, and I know some people worm monthly. There is no one right answer for frequency for all flocks. If you know you have a parasite issue, then when you see symptoms or evidence, it's time to worm again. Time and trial will tell you how often it's needed in your flock. The medications are pretty safe, I've never hurt one by worming them.
An inexpensive digital kitchen scale works well for getting weights. I just put a light plastic plate on it, zero it, and then set the chicken on it.
If you can't get a fecal test done, then I would worm and see if you get improvement. If you do, then that is some small confirmation that it could be the problem. Every flock is different, every environment is different. For some people worming once or twice a year may be all that is needed to keep them healthy. Some flocks may need it more often. I have a very parasite heavy environment (roundworm in my case) and have to worm every 3-4 months, and I know some people worm monthly. There is no one right answer for frequency for all flocks. If you know you have a parasite issue, then when you see symptoms or evidence, it's time to worm again. Time and trial will tell you how often it's needed in your flock. The medications are pretty safe, I've never hurt one by worming them.
