Protozoans and Apicomplexans

What are protozoans?

Unicellular organisms that are more advanced than bacteria.

What body fluids can protozoans infect?

Blood, muscle, lymph, CNS, skin, and mucosa.

What are the four major phyla of protozoans?

Flagellates, Amoeba, Ciliates, and Apicomplexans.

What is an oocyst?

A cyst that can survive outside of a host for long periods.

What is a trophozoite?

The motile and active feeding stage of protozoans.

What is a sporozoite?

The motile and infectious form of a sporulated cell that infects a new host.

What is a merozoite?

A non-motile cell form of reproduction of sporozoites within a host cell.

What is a bradyzoite?

A slow-growing feeding stage of protozoans.

What is a tachyzoite?

A fast reproducing stage of protozoans.

What are flagellates?

Protozoans with long whip-like tails, may have more than one tail.

What are amoebae characterized by?

Pseudopodia, or 'false feet', used for movement.

What are ciliates?

Protozoans that use fine hairs (cilia) for swimming movement.

What are apicomplexans?

The most diverse and complicated protozoans, parasites of almost every animal phylum.

What is the primary diagnostic method for detecting trophozoites?

Direct smear of fresh, unrefrigerated feces.

What is the fecal flotation method used for?

Detection of cysts in solid or semisolid stools.

What disease is caused by Giardia spp.?

Giardiasis or Giardiosis.

What is the route of infection for Giardia spp.?

Fecal-oral transmission through ingestion of cysts.

What are the clinical signs of giardiasis?

Weight loss and chronic diarrhea or steatorrhea.

What is the treatment for giardiasis?

Fenbendazole and Metronidazole.

What disease is caused by Entamoeba histolytica?

Amoebic dysentery.

What are the clinical signs of infection with Entamoeba histolytica?

Acute or chronic diarrhea and ulceration within the intestine.

What is the primary diagnostic method for Entamoeba histolytica?

Fecal float and direct smear for trophozoites.

What is the treatment for Entamoeba histolytica?

Metronidazole.

What disease is caused by Cystoisospora spp.?

Coccidiosis.

What are the clinical signs of coccidiosis?

Hemorrhagic diarrhea, weight loss, and dehydration.

What is the treatment for Cystoisospora spp. infection?

Sulfadimethoxine.

What is the zoonotic potential of Cystoisospora spp.?

No zoonotic potential.

What is the prepatent period for Cystoisospora spp.?

7 to 14 days.

What are the characteristics of unsporulated oocysts of Cystoisospora spp.?

Round, non-motile, with a single nucleus.

What are the characteristics of sporulated oocysts of Cystoisospora spp.?

Egg-shaped with 2 sporocysts, infective stage.

What is the primary method for diagnosing Cystoisospora spp.?

Fecal testing and visualization of oocysts.

What is the drug of choice for treating Cystoisospora spp. infections?

Sulfadimethoxine (Albon).

What is the initial dose of Sulfadimethoxine for treating Cystoisospora spp.?

25 mg/lb (55 mg/kg).

How long should treatment with Sulfadimethoxine last?

10 to 14 days.

What is a common off-label drug used for Cystoisospora spp.?

Ponazuril (Marquis).

What are the recommended fecal exam frequencies for pets in the first year?

2 to 4 times.

What is the route of infection for Toxoplasma gondii?

Ingestion of oocysts through food, water, or grooming.

What clinical signs are associated with Toxoplasma gondii infections?

Usually asymptomatic, but diarrhea is a major symptom.

What is the unique fact about oocyst shedding in cats infected with Toxoplasma gondii?

Cats shed oocysts for only up to 2 weeks.

What are the characteristics of unsporulated oocysts?

Round, non-motile, and have a single nucleus.

What are the characteristics of sporulated oocysts?

Infective stage, round or egg-shaped with 2 sporocysts.

What is the primary disease caused by Cryptosporidium spp.?

Cryptosporidiosis.

What is the route of infection for Cryptosporidium spp.?

Fecal-oral route.

What are common clinical signs of Cryptosporidiosis?

Profuse, watery diarrhea.

What is the drug of choice for treating Cryptosporidium spp. infections?

Azithromycin.

What is the prepatent period for Cryptosporidium spp.?

Oocysts are shed in feces 3 to 6 days after infection.

What is the disease associated with Leishmania infantum?

Viscerocutaneous/Canine leishmaniosis.

What is the route of infection for Leishmania infantum?

Bite of infective sand flies (Phlebotomus spp.).

What are common clinical signs of Leishmania infantum infections?

Skin lesions, ocular abnormalities, weight loss, and lethargy.

What is the primary host for Babesia canis?

Canines.

What is the route of infection for Babesia canis?

Bite of infective Rhipicephalus sanguineous (Brown dog tick).

What are common clinical signs of Babesiosis?

Lethargy, pale mucous membranes, splenomegaly, and icterus.

What is the treatment for Babesia canis?

Clindamycin.

What is the disease caused by Cytauxzoon felis?

Feline cytauxzoonosis.

What is the route of infection for Cytauxzoon felis?

Bite from infected Amblyomma americanum (Lone Star Tick).

What are the clinical signs of Cytauxzoon felis infections?

Anemia, icterus, dehydration, fever, and death.

What is the treatment for Hepatozoon americanum?

Trimethoprim-sulfadiazine, clindamycin, and pyrimethamine.

What is the route of infection for Hepatozoon canis?

Ingestion of infective Rhipicephalus sanguineous (Brown dog tick).

What are the clinical signs of Hepatozoon canis infections?

Nonspecific symptoms including fever, lethargy, and depression.