Helminthosis is the disease caused by the presence of helminth parasites within or outside the gastrointestinal tract of an individual. All species of animals can be infected with helminth parasites. The infection usually is more severe in the very young and the very old or immuno compromised individuals. Some adult animals can thrive fairly well while infected with some helminth parasites without showing obvious clinical signs while the vast majority suffer reduced productivity under heavy worm burdens. It appears some breeds of animals are more resistant to certain helminth parasites than others. Helminthosis has been a long time standing problem against breeding of fish hosts leading to economic loses that may reach billions of dollars.