Abstract

Parasitic diseases remain a major constraint to livestock productivity across all agro ecological zones and production systems in Africa, and gastrointestinal nematodes remain a major economic importance in domesticated livestock throughout the world [1] being the chief parasitizes responsible for disease-related production losses arising from stock mortality, severe weight loss and poor production, especially in small ruminants. The World Health Organization estimates that a staggering 2 billion people harbour parasitic worm infections. Parasitic worms also infect livestock and crops, affecting food production with a resultant economic impact. Also of importance is the infection of domestic pets. Indeed, the companion animal market is a major economic consideration for animal health companies undertaking drug discovery programmes. The parasitic helmets of animals are broadly classified into nematodes (round worms, whipworms, hookworms, pinworms, threadworms, and filarial worms), custodies (tapeworms), treaties (flukes, schistosomes), annelids (leaches) and acanthocephalans (thorny-headed worms). In the animal’s body, the gastrointestinal tract is the abode of many helmets, but some live in tissues or their larvae migrates into tissues [2]. In ruminants, the most common cause of clinical helminthias is from infection with gastrointestinal nematodes of the order strongylida. The next most important parasite of sheep and cattle is the liver fluke. The major parasitic worm disease of horses is also generated by strongly round worms whose adult are blood suckers and whose larvae may cause colic, whereas their large scared nematode infections are rarely pathogenic. Fluke and tapeworms are rarely a cause for concern in equines. Pigs are infected by very large acaroids and by strangles but rarely suffer from pathogenic disease. Poultry and geese are susceptible to infection with an assortment of different helmets. Habitual parasites of domestic cats and dogs are intestinal tapeworms and scared nematodes. Dogs can suffer from pathogenic hookworm infections, particularly in warmer climates, where they may also be afflicted with heartworms [3].