Protozoan agents in hemolytic anemia

Hemolytic anemia is one of the most important problems within the clinical veterinary medicine. One of the major types of this anemia is hemolytic anemia caused by the animal-like protozoa. The disease causes a severe reduction in red blood cells and results in undesirable consequences such as hypovolemic shock. The causative agents, protozoa, are eukaryotic unicellular microorganisms (some motile) belong to the Kingdom Protista. Most of the protozoa, such as those symbiotically live in ruminants' gasterointestinal tract, are free-living organisms while some others are parasites. Protozoan blood parasites infect humans and a wide variety of animals including mammals, birds and amphibians. These microorganisms usually form two different types: cyst and trophosoite. Cyst is the inactive and very persistent form of the protozoa while trophozoite is the active and living form of them. Protozoa are often transmitted to their hosts by arthropods. Because of the importance of circulatory system in animal health and due to the widespread of parasitic anemia within the livestock populations, study of blood parasites is of great priorities. Identification of parasitic infections and their clinical symptoms can lead to early diagnosis and treatment of the infection and therefore reduction of animals' mortality and also increase of dairy products.