i dont know about the best treatment but parasites live in the dirt, plants, and everywhere around us.. from what i've learned from my own expeirence they mostly get them when they eat something that was a host of the parasite, like a bug or a worm... if your feeding your animals any meats always cook them thoroughly like you would yourself..
signs of parasites would be:
FOAMY STOOLS or
sometimes mucousy stools, loose stools, really smelly stools (and you didnt just give them greens), eating alot but really skinny, and a lethargic bird. anemia which is low iron, causes paleness. vitamin deficiencies which can cause numerous physical problems, unhealthy looking feathers, skin, scaly legs. drops in egg production, respiratory problems...the list goes on.. but thats what was in my head.
treat to prevent is alot better if your free ranging, rather than treating the problem once its there.
i found this on the internet about specific worms:
"Worms in Chooks
There are three classes of gut parasites
Roundworms
Tapeworms
Flukes (flukes are the most rare but hardest to get rid of)
Worms
Worms can sometimes be found in the intestines of chickens. When chickens are kept on a litter floor, the worms will have direct cycle through their droppings. Worm eggs are discharged in the droppings; after the worm eggs incubate in the litter for about 10 days they will contain larvae, and other chickens will pick up these embryonating worm eggs and become infected with worms.
A severe infestation can also cause an intestinal obstruction and result in death. Sometimes a bird will contract both an ascarid and a cocci infection at the same time, and because of the synergistic relationship between the two, will sucb more readily than if they were only stricken with one infection or the other. In rare but do***ented cases, an ascarid can actually find its way into a henâs egg, which can be quite unappealing to an unsuspecting fresh egg customer. The worm can be detected by candling.
two major kinds of worm exist:
1. Roundworms (Ascaridia galli)
These are large worms up to 3 inches long that can live in the intestine, use the chicken's nutrients while the larvae damage the intestinal wall. Piperazine, a common harmless wormer, will eliminate roundworms, but reinfection of the chickens can occur through the litter. Piperazine should be given in the drinking water twice, with a 3-week interval.
Roundworms can cause drops in egg production, but normally do not harm the birds severely. However, intestinal absorption of nutrients will be interfered with.
2. Hairworms (Capillaria).
These worms are much smaller than roundworms, approximately 1/2-inch in length and very thin threadlike. Therefore they are difficult to find in the intestinal contents. Capillaria have a direct litter bird cycle or an indirect cycle via earthworms, the latter being a factor in chickens that range outdoors. Capillaria cause considerable damage to the intestinal wall and can deprive the chicken of nutrients and vitamins.
Platinum yolks can be found in eggs from infected hens as well as paleness of the birds themselves.
Treatment with piperazine does not eliminate capillaria, and other wormers will have to be used. The feed is often supplemented with extra vitamin A in capillaria-infected chickens.
In addition to these two commonly occurring worms in chickens, we can find other kinds that are of lesser importance:
3. Cecal worms (Heterakis)
These are worms that inhabit the ceca (blind sacs in intestine), but do not appear to cause sickness in chickens.
4. Tapeworms
Tapeworms are occasionally found in chickens. They require special treatment, but usually do not constitute a hazard to the chicken's health, unless large numbers are present.
5. Gapeworms
Gapeworms occupy the trachea of pheasants primarily, but may be found in chickens, too. Cause gasping in pheasants and young chickens. Special wormer is required for gapeworms. Gapeworms cycle through earthworms, so chickens will get infected only outdoors or on dirt floors.
In an average chicken flock with floor operation, good management practices and periodical piperazine or other worm treatment when roundworms or hairworms are present will keep the flock healthy. If severe worm problems exist, a good worming program should be instituted, for which advice can be obtained from the Extension Service. Wire floors eliminate the worm cycle and keep chickens free of intestinal worms.
Birds with gapeworm infestation show signs of respiratory distress due to both the damage to the lungs and to the trachea that is caused by the worms. Young birds and bantams are especially vulnerable due to their relatively small trachea. Symptoms include depression, gasping for breath, and head shaking in an attempt to remove the worms from the trachea. Tracheal rales (a gurgling sound made during breathing that accompanies tracheal irritation) can be heard in many cases, and can sometimes be mistaken for an upper respiratory infection of some other cause.
The most commonly known worm âhostsâ (carriers) are the earthworm, cockroach, beetle, sowbug, grasshopper, and earwig. The earthworm is known specifically to carry the gapeworm.
In the case of the gapeworm, once a susceptible bird ingests an infested earthworm, the larvae penetrate the wall of the intestine and eventually end up in the lungs. Once in the lung, the larvae migrate into the bronchi. A molt of the larvae takes place resulting in the adult gapeworm, and the adult worms migrate up the respiratory tree to the trachea where the male and female worms intertwine and attach themselves to each other permanently. The entire process from the time the bird ingests the earthworm to the time adult gapeworms can be found in the trachea is approximately 7 days.
Gapeworm egg production begins about 14 days after infestation of the larvae. The eggs are then coughed up into the mouth of the bird and passed out into the faeces. In the droppings, the eggs incubate for 8 to 14 days under optimum conditions of temperature and moisture to become infective larvae, thus completing the life cycle.
Under necropsy, the adult gapeworms appear as long, red strands attached to the tracheal wall, almost like thin strands of blood. In chronic infestations, nodules of inflammatory tissue appear in the tracheal wall at the site of worm attachment. You can imagine how difficult it would be to breathe normally under these conditions.
According to ancient wisdom the best time to treat worms is when they are most active â when the moon is waxing full
by K. J. Theodore"
theres more if you want toread it here:
www.thepoultrysite.com/forums/showthread.php?p=937
then theres this article which is interesting also:
http://www.smallholder.co.uk/poultry/976875.worms_in_waterfowl_and_poultry/
it mentions quote:"...Earthworms and also snails, slugs, ants, flies and beetles are often the intermediate hosts for various internal parasites of birds; so winter is a good time to use medication..."
and also "Worms in poultry - Parasitic worms are, of course, much more common in free-range poultry than in cage systems where, in theory, the birds should be parasite-free. For example, a Danish study showed that Ascaridia galli were found in 64% of free range birds, 42% of deep-littered birds and in only 5% of battery hens."
so if you free range like i do, its best to treat to PREVENT, rather than treating when your trying to get rid...