Unfortunately, internal parasites are a fact of life when you raise goat or any form of livestock. The negative impact Internal parasites have on your goats will depend on:
· The number of adults in the intestinal tract, the number of eggs laid and the number of infective larvae ingested by the host
· immune status of host
· the age of the host
· the nutritional status of the host
· the time of the year
· the nature of the parasites migration
· where they live as adults
· how they obtain their food from the host
· the deworming strategies used by the producer
· the parasites resistance to the dewormer used
· the environmental conditions
· pasture and browse management
Over the centuries and through evolution parasites have developed a very complex relationship with their host. They have adapted to survive within the intestinal tract and outside the body. Within the body and intestinal tract they are exposed to destructive antibodies, concentrated acids in stomach, digestive enzymes, changes in pH, and numerous bacteria, fungi, and protozoa that make up the intestinal environment. They have also developed resistance to the drugs used to kill them.
Outside the body they have adapted to changes in the climate, and. periods of starvation. It is little wonder that the parasites have survived man's attempt to eliminate them at best we can only control them.
Internal parasites come in all shapes ranging from a microscopic single cell organism (coccidia) to visible complex multicellular organisms, like flukes, the barber pole worms, and tapeworms.
To better understand life cycle and survival of these parasites I would like to take you on a journey as you travel with a parasite through its lifecycle within the external environment and the host. Parasites either have a direct life cycle or require more than one host in order to complete its lifecycle.
Direct life Cycle of the Nematode Worm A Personal Adventure
Hi my name is Barbara Pole my family is the Barber Pole Worm Family Haemonchus contortus I started my life as an egg laid by my mother within the intestinal tract of my host. I, along with my many siblings leave the intestinal tract safe within a fecal pellet. Over a short period of time I hatch into a first stage larvae during this stage I eat the microorganisms I find in the feces and the soil eventually I mature into a second stage larvae as I grow must shed a protective outside membrane called the cuticle. I continue to eat the microorganisms I find in my environment and soon have grown into a third stage larvae. At this stage I discover that I did not shed the cuticle in fact I've developed another cuticle that seems to be inhibiting my ability to eat. It is time to find another place to live. Every morning I travel up a blade or moist grass waiting for a goat to eat me. As the sun gets hotter and the grass dries out I retreat back down to the cooler ground. I must wait for another day. I must find a host within the next few months, so long as the grass remains long and air humid. As soon as winter comes, I will likely starve and freeze to death.
Finally I am eaten with the help of digestive enzymes in my host’s rumen, I lose my cuticle and turn into the a four stage larvae. Finally I reach the abomasum where I feast on organisms living on the surface of the stomach and small intestines. If I am eaten in the fall I may rest at this stage until the spring. In the spring, hungry from my winter’s fast ,I mature along with my many siblings and settle into the stomach lining and dine on the blood of my host. Unfortunately if there are too many of us we cause great distress and perhaps even death to our host by taking too much blood.