Protozoa
Protozoa are unicellular eukaryotic organisms. Protozoa are heterotophs meaning that they feed on organic materials to provide the nutrients needed for growth and reproduction. Protozoa are motile and use flagella to move around aqueous environments. Many protozoa have two distinct life stages that they can alternate between. The first stage is when the protozoan is motile, growing, feeding and reproducing. The second stage is the stage, when the protozoan is dormant. In the encysted form protozoa are extremely resilient to conditions such as lack of nutrients, extreme temperatures and various chemicals. This makes combating parasitic forms of protozoa hard to combat. Most protozoa have an intermediate host & a definitive host. Common protozoa include:
Endoparasites
Endoparasites are commonly called worms. Endoparasites are multicellular organisms that commonly inhabit the gastrointestinal tract as well as the circulatory system of host animals. Endoparasites acquire nutrients from the host tissues and release toxins as waste products that are absorbed into the host’s blood stream. Most endoparasites reproduce by laying , but some are able to detach egg-filled body segments that are passed in the feces of the host animal. Endoparasitic eggs are then ingested by other host animals. Endoparasites gain access to host tissues through the skin, mouth, nose, or anus and migrate to their preferred tissues. The three major classifications of endoparasites are nematode, cestode and trematode. Another common internal parasite that affects the horse is gasterophilus or the . Common worms that affect the horse include:
Ectoparasites
Ectoparasite describes a wide variety of organisms that cause harm to an animal at its surface, or skin. Most common ectoparasites are arthropods, or , that bite or suck nutrients from host animals. Some ectoparasites live on the host body surface while others only feed there. In addition to their ability to deplete a host’s resources many ectoparasites are for the transmission of disease or leave the host vulnerable to secondary infection by another agent. The larval stages of some ectoparasites are worm-like and may be found inside body tissues. Common ectoparasites that affect the horse include:
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