Protozoan infections in animals refer to diseases caused by the invasion and colonization of one or more protozoan species in an animal host's body. Protozoa are single-celled eukaryotic organisms that can exist as parasites and can be transmitted through various modes, such as direct contact with infected animals, contaminated food or water, vectors like insects, and fecal-oral route.

Examples of protozoan infections in animals include:

1. Coccidiosis: It is a common intestinal disease caused by several species of the genus Eimeria that affects various animals, including poultry, cattle, sheep, goats, and pets like cats and dogs. The parasites infect the epithelial cells lining the intestines, causing diarrhea, weight loss, dehydration, and sometimes death in severe cases.
2. Toxoplasmosis: It is a zoonotic disease caused by the protozoan Toxoplasma gondii that can infect various warm-blooded animals, including humans, livestock, and pets like cats. The parasite forms cysts in various tissues, such as muscles, brain, and eyes, causing mild to severe symptoms depending on the host's immune status.
3. Babesiosis: It is a tick-borne disease caused by several species of Babesia protozoa that affect various animals, including cattle, horses, dogs, and humans. The parasites infect red blood cells, causing anemia, fever, weakness, and sometimes death in severe cases.
4. Leishmaniasis: It is a vector-borne disease caused by several species of Leishmania protozoa that affect various animals, including dogs, cats, and humans. The parasites are transmitted through the bite of infected sandflies and can cause skin lesions, anemia, fever, weight loss, and sometimes death in severe cases.
5. Cryptosporidiosis: It is a waterborne disease caused by the protozoan Cryptosporidium parvum that affects various animals, including humans, livestock, and pets like dogs and cats. The parasites infect the epithelial cells lining the intestines, causing diarrhea, abdominal pain, and dehydration.

Prevention and control of these diseases rely on various measures, such as vaccination, chemoprophylaxis, vector control, and environmental management. Public awareness and education are also essential to prevent the transmission and spread of these diseases.

Dinoflagellida is a large group of mostly marine planktonic protists, many of which are bioluminescent. Some dinoflagellates are responsible for harmful algal blooms (HABs), also known as "red tides," which can produce toxins that affect marine life and human health.

Dinoflagellates are characterized by two flagella, or whip-like structures, that they use for movement. They have complex cell structures, including a unique structure called the nucleomorph, which is the remnant of a former endosymbiotic event where another eukaryotic cell was engulfed and became part of the dinoflagellate's cell.

Dinoflagellates are important contributors to the marine food chain, serving as both primary producers and consumers. Some species form symbiotic relationships with other marine organisms, such as corals, providing them with nutrients in exchange for protection and other benefits.