Parasites are the source of the majority of problems in commercial herds, especially those subject to incoming replacement animals. All new animals should be wormed and isolated as a matter of course before introducing them to the established herd. The only way to insure that the new goats are absolutely worm free is to perform a fecal analysis 10 days to 2 weeks after worming. Then they may be introduced to the general population without significant risk.
Normally, large commercial producers worm twice a year; just prior to breeding and again just prior to kidding. It is a good idea however to perform a whole herd fecal analysis at three month intervals throughout the year. Some worms are indeed stubborn and may hide in tissues, waiting to pop up at inopportune moments. Also, constant vigilance may show that worming may not be necessary at all if oocyst counts remain low. Remember that many diseases are caused by stress and it is stressful to capture and worm an unruly goat. It is much easier to collect a freezer bag full of fresh feces from a significant number of pellet piles and run a test. Be careful to collect only “damp” pellets, seal the bag carefully and refrigerate the bag if not delivered to the laboratory immediately. In hot, humid areas with parasite problems, does may be wormed 30 days before kidding and again one to three days after kidding. A follow-up may be necessary 30 days after that. Parturition tends to stimulate dormant worms into activity. Again, the stress involved with working the herd may result in lost kids. Kids should be wormed at weaning and again prior to the breeding season.
Worms themselves can develop resistance to worming medicine. In this way, parasites can return even after routine worming has occurred. It is wise to annually rotate the type of anthelminthic used between the “clear” (Ivomec, levamisole, thiabendizole) and the “cloudy” (Panacur, Valbazen, fenbendizole) to minimize the development of resistant worms.
Internal parasites that cause the greatest concern in goat populations are coccidiosis (Eimeria), stomach worms (nematodirus, trichostrongylus, strongyles, trichuris and haemonchus) and the dreaded liver fluke. Coccidiosis will also be dealt with here.
Be sure to consult a local veterinarian when designing a goat parasite control program. These guidelines are intended as such and are not intended to be used alone. Individual situations will vary. Parasitism can mean the difference between making and breaking an operation. Please pay attention.