The following information is presented as gained knowledge from years of dealing with farm animals. I strongly advise that you use this information as a guideline to your own animal husbandry needs.
It should be noted that there is no advice on eradicating parasites, as this is not possible without killing the animal. The following centers on parasite control.
From the time man was given dominion over all the animals of the earth, he took this gift but did not keep the other side of the bargain. The animal husbandry that should have been applied to the animals under his care was soon discarded in the face of profit.
Mankind became a meat eater, the earth's temperature had changed and warm clothes were required, both these items came from the animals. So began the profiteering, which brought the massive herds of animals to cater for the market as the worlds population grew and grew.
In the early days, when nomadic tribes herded goats and sheep around the arid countryside of the middle-east, foraging for sustenance for the stock, but not moving far from the wells and water holes, which were owned by various tribes, there seemed that there was no reason to fear intestinal parasites, either in man nor beast, as the country and the absence of the micro-climate of lush pasture,the breeding grounds of parasites, did not exist.
With all the treatments now for the parasites, nothing works better at their control than dry harsh conditions, such was encountered by the early herders.
Of all these domestic animals,the goat is the one that is most effected by internal parasites. Sheep have many parasites in them, cattle have another group of intruders; however the poor goat suffers from both cattle and sheep parasites, and is also the host to a few of its own. By the time a goat has been drenched clear of these pests, the goat itself is suffering to the point where it will die from the treatment.
The goat has the perfect intestinal habitat for parasites. The goat's stomachs are a forever working engine for the extractions of as much nutrient that is possible to extract from that dry climate from whence its species originally came.
Using commercial drenches is fraught with danger, in itself, if in the hands of someone that does not have a full understanding of the animal, the chemical and the parasite they are trying to get maintain control over.
Wide Spectrum drenches, as is Chemotherapy chemicals in humans, try and hit at all the worms, (cancer cells) and suspected worms in the goat, and other animals, The Shotgun effect is used to describe wide spectrum drenches and Chemo. Chemicals, however the drench also kills the good bacteria that is needed to keep the goat 'ruminating', just as Chemo Chemicals kill all body cells if taken in too big a dose.
Many ruminant animal owners of today think that it is better to give 'just a little more' than the recommended dose of drench, thus any parasite that survives the treatment is then developing an immunity to the toxic chemicals.
It should be taken into consideration that the Chemical Companies may add 'Just a little more' to the recommended dose so that they can stay competitive in the market place. We would like to think that these companies do not 'fiddle' with our animals life, but there is that possibility.
One should be more inclined to give “just a little less' than the recommended dose, or at least the exact dose as suggested on the packaging. Giving a little less contributes to the immunity problem with parasites. It is a catch 22.
The best way to treat an animal for parasites is to determine what parasite is in the animal and just use specific drenches. A vet check is required to determine the parasite and at what stage it is, and what effects it is having on the animal. Weighing the animal, not guessing the weight will also determine the dosage.
If a wide spectrum drench is then advised, at lest you are not over dosing.
To just assume that you animals have all the parasites available, and to use the broad spectrum drench is costing you more than you should pay, and is detrimental to the animal in the long term.
Naturally this close husbandry is not practical in the large sheep and cattle herds of this continent, but by the small land holder taking care not to add to the already immune parasites, they will be assisting all animal industries.
In the large, mostly arid properties, the worm problem is known, adn less than in coastal areas. The graziers of the Outback, drench according to well know worm problems.
The rumbling you hear in a goats stomach is a sign that the animal is functioning as it should. The cud chewing process keeps the bacterial content in a good and healthy environment. Some success in recovering an ill goat has been to take the cud from a healthy goat and feed it to the unhealthy goat, as this has had the effect of re-starting the bacteria.
The goat was the most successful animal for use by humans in the early times, as almost all of the animal was used to provide for mankind. Very low fat meat, milk, clothing, the stomach was use for water bags used by the herders, with other intestinal delicacies being available. It was said that the only part of the goat that was not used was the 'Bleat'.
Breeders of ruminants should understand a little of the goats health and husbandry requirements to help with parasitic problems with other animals.
There has been an immune Barbers Pole worm in the New England area of New South Wales since 1938.
The stock owner, on all holdings, should consider the fact that you will never completely clear the animal of Intestinal Parasites, and you should not aim for this, as those parasites remaining give the stock a chance to build an immunity to the parasite. The off side is that the Parasite will often develop an immunity to the drench, thus the sensible rotation of various drenches is often the best practice. You should ensure that an entirely different chemical is in the exchange drench. In practice, keep one general use drench, and intersperse with a complete, once a season drench/s. It is pointless interchanging with a drench that has the same chemicals as your general use drench.
http://www.parasitesandvectors.com/content/6/1/153 Highly recommended Web Site.
http://www.vetmed.wsu.edu/depts-vth/camelids/parasiteControl.aspx From American Specialists notably Camelids.
Where there is good rainfall, lush grasses, water laying on the ground in pools, and the gently running stream inhabited with the black snail that is needed to complete the life cycle of Liver Fluke. This is the perfect micro-climate for many of the intestinal parasites for all ruminants, and horses, dogs, bird life and etc. One must not forget that parasites, such as Liver Fluke is readily transferable to humans.
It is this type of climate that paddock rotation will be one of the greatest controllers of parasites, as all parasites have a term on the ground before they are ingested to go to the adult, egg laying cycle in the host animal.
Paddock rotation has been said to be useless for the control of parasites, however in all the rotation suggestions I have seen there is no mention of drenching onto a rested paddock, and it is presumed that you rest a paddock then at the end of six to eight weeks you let infected stock onto that paddock. This is a ridiculous as it sounds, you are just reinfecting the rested paddock with the eggs of the host's worm population.
Paddock rotation is to be treated seriously, and no like animal should be allowed to walk across the resting paddock, lock the gate if there is some temptation to lead the Llama, sheep or cow through 'Just this once'. As stock walk about infested paddocks, they not only ingest the larvae on the fodder, they pick larvae up on their legs, which can be dropped off onto the grass again somewhere else.
Investigation is of great assistance in parasite control.
The author is not a veterinarian, nor does he have a connection with worm treatment chemical companies. The above information that he has gathered over a long time with animals, and in agreement with some internet information is for consideration of the stock owner. This compilation of information is offered in good faith, and with no guarantees.