Protozoa Classification & Veterinary Significance in Animals

What are the four main classification groups of protozoa based on movement?

Flagellates, Amoebas, Apicomplexans, Ciliates

What is the primary characteristic of the Kingdom Protista?

Unicellular organisms grouped mainly by how they move in their environments.

What are the two forms of protozoa?

Cyst stage (resistant to harsh conditions) and Trophozoite stage (motile and typically found inside the body).

What are the specialized anatomical features of Flagellates?

Trophozoites are bullet/pear-shaped with 1-2 whiplike appendages (flagella).

What is an example of a Flagellate?

Giardia spp.

How do Amoebas move?

They move via pseudopods (false feet) and are blob like in shape.

What is an example of an Amoeba?

Entamoeba histolytica.

What distinguishes Apicomplexans from other protozoa?

They have complex life cycles and are often banana or boomerang shape

What is an example of an Apicomplexan?

Toxoplasma gondii.

What is the movement mechanism of Ciliates?

They are covered in tiny hairs (cilia) for movement.

What is an example of a Ciliate?

Balantidium coli.

What is the zoonotic potential of Giardia spp.?

Giardia duodenalis can infect humans, dogs, and cats, with various assemblages affecting different species.

What are the clinical signs of Giardia spp. infection?

Diarrhea lasting 1-2 weeks, watery stools, foul-smelling stools, abdominal discomfort.

What is the infectious stage of Giardia spp.?

Only cysts are infective and are resistant in the environment.

What is Bovine Trichomonosis caused by?

Tritrichomonas foetus.

What are the clinical signs of Bovine Trichomonosis in cows?

Infertility, spontaneous abortion, and mucopurulent discharge.

How is Bovine Trichomonosis typically spread?

Through natural service (breeding) between bulls and cows.

What is the treatment for Bovine Trichomonosis?

Cull all infected bulls; no approved drugs for cows/heifers.

What is Feline Trichomonosis caused by?

Tritrichomonas foetus.

What are the clinical signs of Feline Trichomonosis?

Cow pie diarrhea, fecal incontinence, and painful anus.

What is Avian Trichomonosis also known as?

Canker in pigeons and songbirds.

What are the clinical signs of Avian Trichomonosis?

Yellow nodules in the mouth, difficulty swallowing, and drooling.

What is the life cycle of Entamoeba histolytica?

Fecal-oral transmission with cysts being the infective form.

What are the clinical signs of Entamoeba invadens infection?

Anorexia, weight loss, vomiting, and blood or mucus in feces.

What is the treatment for Entamoeba invadens?

Metronidazole.

What is the significance of cysts in protozoa?

Cysts are the resistant form that can survive harsh environmental conditions.

What is the prevention strategy for Bovine Trichomonosis?

Test all bulls before introduction to the herd and use artificial insemination.

What is Balantidium coli?

A ciliate of swine, considered a normal part of the GI flora of mammals and is non-pathogenic

Under what conditions can dogs contract Balantidium coli?

When normal flora is out of check due to other GI diseases or if they spend time around pigs.

What is an oocyst in Apicomplexa?

The result of sexual reproduction, round to oval in shape, variable in size, and environmentally resistant.

What is the difference between unsporulated and sporulated oocysts?

Unsporulated oocysts are not infectious and contain a diploid single cell (zygote), while sporulated oocysts are infectious and contain haploid sporozoites.

What is a zoite in Apicomplexa?

The functional unit of all Apicomplexans, motile, banana-shaped, and specialized for cell invasion.

What are sporozoites and merozoites?

Sporozoites are the infective stage from sporulated oocysts, while merozoites are produced in host cells through asexual reproduction.

What are the two significant genera of enteric coccidiosis in veterinary medicine?

Eimeria and Cystoisospora.

What is the significance of Cystoisospora in dogs and cats?

It causes coccidiosis and is the most diagnosed protozoan in puppies and kittens.

What is required for Cystoisospora oocysts to become infective?

They must become sporulated in the environment.

What is the life cycle of Cystoisospora?

Oocysts are ingested, develop into sporozoites, which infect intestinal cells and asexually reproduce into merozoites.

What are the main species of Eimeria affecting cattle?

Eimeria zuernii and Eimeria bovis.

What symptoms do calves experience with Eimeria infections?

Profuse and projectile diarrhea with tenesmus, and they are susceptible to secondary infections.

What is Isospora suis known for?

Causing severe disease in nursing piglets, characterized by yellow-grey pasty diarrhea.

What is Toxoplasma gondii?

An intestinal coccidian of cats, highly zoonotic to humans, with pregnant women being at the highest risk.

What are the life cycle phases of Toxoplasma gondii?

Oocysts, tachyzoites, and bradyzoites.

What is the role of tachyzoites in Toxoplasma gondii's life cycle?

They are rapidly dividing stages that cause acute systemic infections.

How can bradyzoites affect hosts?

They are slowly dividing, encysted tissue stages that lead to chronic infection and can reactivate when ingested.

What precautions should be taken regarding Toxoplasma gondii?

Quarantine cats if shedding oocysts, dispose of litter properly, avoid raw diets, and keep cats indoors.

What is the significance of oocysts in Toxoplasma gondii?

They are only shed by cats, created by sexual reproduction, and resistant in the environment.

What is the recommended temperature for cooking meat to prevent Toxoplasma infection?

Above 160 degrees Fahrenheit.

What is the impact of gardening while pregnant in areas frequented by feral cats?

It poses a risk for Toxoplasma infection; gloves should be worn.

What is the primary concern regarding Toxoplasma gondii for pregnant women?

It can cause hydrocephaly in the fetus.

What is an oocyst in Apicomplexa?

The result of sexual reproduction, round to oval in shape, variable in size, environmentally resistant, and requires sporulation to become infective.

What are the two types of oocysts in Apicomplexa?

Unsporulated oocysts (not infectious, contain diploid zygote) and sporulated oocysts (infectious stage containing haploid sporozoites).

What is a zoite in Apicomplexa?

The functional unit of all Apicomplexans, motile, banana-shaped, and specialized for cell invasion.

What are sporozoites and merozoites?

Sporozoites are the infective stage derived from sporulated oocysts, while merozoites are produced in host cells through asexual reproduction.

What are the two genera of Apicomplexans of veterinary significance?

Eimeria and Cystoisospora.

What is the significance of Cystoisospora?

It causes coccidiosis in dogs, cats, and pigs, and is the most diagnosed protozoan in puppies and kittens.

What is the life cycle of Cystoisospora?

Oocyst must become sporulated to be infective; sporozoites infect intestinal cells and reproduce asexually to form merozoites.

What are the symptoms of Eimeria infections in calves?

Profuse and projectile diarrhea with tenesmus, and susceptibility to secondary infections like pneumonia.

What is the primary host for Toxoplasma gondii?

Felines (cats) are the definitive host.

What are tachyzoites and bradyzoites in Toxoplasma gondii?

Tachyzoites are rapidly dividing stages causing acute infections; bradyzoites are slowly dividing, encysted tissue stages associated with chronic infection.

What is the zoonotic risk associated with Toxoplasma gondii?

It is highly zoonotic, especially concerning for pregnant women due to risks like hydrocephaly in fetuses.

How can Toxoplasma gondii be prevented?

By quarantining infected cats, disposing of litter properly, cooking meat above 160 degrees, and keeping cats indoors.

What is the role of sporulation in oocysts?

Sporulation is necessary for oocysts to become infective.

What happens to merozoites after they are released?

They develop into microgametes (male) and macrogametes (female) for sexual reproduction.

What is the specific anatomic feature of Eimeria leuckarti?

It has a micropyle (exit pore) in its oocyst.

What is the primary method of transmission for Cystoisospora?

Transmission occurs through ingestion of sporulated oocysts.

What is the diagnostic stage of Cystoisospora?

The oocyst is the diagnostic stage.

What is the impact of stress on coccidiosis in swine?

Stress is a main contributor to severe disease in nursing piglets caused by Isospora suis.

What is the typical outcome of Eimeria infections in ovine and caprine species?

Caprine species are more susceptible and typically die from infections.

What is the primary concern for immunocompromised individuals regarding Toxoplasma gondii?

They are at higher risk for severe infections and complications from exposure.

What is the significance of Cystoisospora in veterinary medicine?

It causes coccidiosis in dogs, cats, and pigs, and is the most diagnosed protozoan in puppies and kittens.

What is the life cycle of Cystoisospora?

Oocyst ingested -> develops into sporozoite -> infects intestinal cells -> asexual reproduction to merozoites -> sexual reproduction to form unsporulated oocyst.

What is Balantidium coli?

A ciliate of swine considered a normal part of the GI flora of mammals and is non-pathogenic.

Under what conditions can dogs contract Balantidium coli?

When normal flora is out of check due to other GI diseases or if they spend time around pigs.

What is an oocyst in Apicomplexans?

The result of sexual reproduction, round to oval in shape, variable in size, and environmentally resistant.

What is the difference between unsporulated and sporulated oocysts?

Unsporulated oocysts are not infectious and contain a diploid single cell (zygote), while sporulated oocysts are infectious and contain haploid sporozoites.

What are the two types of zoites in Apicomplexan life cycles?

Sporozoites (infective stage) and merozoites (produced in host cells).

What is required for Cystoisospora oocysts to become infective?

They must become sporulated in the environment.

Which species of Eimeria are significant in bovine coccidiosis?

Eimeria zuernii and Eimeria bovis.

What are the symptoms of Eimeria infections in calves?

Profuse and projectile diarrhea with tenesmus, leading to secondary infections like pneumonia.

What is the primary concern regarding Toxoplasma gondii?

It is highly zoonotic to humans, especially concerning for pregnant women due to risks like hydrocephaly.

What are the life cycle phases of Toxoplasma gondii?

Oocysts (shed by cats), tachyzoites (rapidly dividing), and bradyzoites (slowly dividing, encysted).

What is the prevention strategy for Toxoplasma gondii in households with pregnant women?

Quarantine cats that shed oocysts, dispose of litter properly, and avoid raw diets.

What is the significance of the micropyle in Eimeria leuckarti?

It is a specific anatomical feature of the oocyst.

What is the primary symptom of Isospora suis infection in nursing piglets?

Yellow-grey pasty diarrhea that smells like soured milk.

What is the main culprit for severe disease in Isospora suis infections?

Stress, especially during farrowing.

What should be done to prevent Toxoplasma gondii infection while gardening?

Use gloves when gardening in areas frequented by feral cats.

What is the role of microgametes and macrogametes in Cystoisospora's life cycle?

Microgametes are male, and macrogametes are female; they participate in sexual reproduction to form unsporulated oocysts.

What is a key characteristic of the oocysts produced by Toxoplasma gondii?

They are resistant in the environment and only shed by cats.

What happens to tachyzoites in the host's body?

They invade tissues and can convert to bradyzoites, leading to chronic infection.

What is the significance of mixed infections in coccidiosis?

Hosts can be simultaneously infected with more than one coccidian species, complicating treatment.