Parasitology Chapter 11 P2 - Protozoans of Ruminants, Swine, and Other Animals

Study material for part 2 of Chapter 11 of Diagnostic Parasitology for Veterinary Technicians. For class BIO225 at MWCC.

Ruminant ciliates

Eimeria bovis and Eimeria zeurnii

• Apicomplexans

• Found: Worldwide​

• Cecum​

• Cause of infection: Ingestion of oocysts​

• Similar life cycle to Cycloisospora​

• Distinguished by oocyst in fecal​

• E. bovis: Oval, micropyle, 20 x 28 um​

• E. zeurnii: Spherical, no micropyle, 15-22 um​

• Diarrhea mostly but can cause muscle tremors, seizures, blindness

Cryptosporidium

• Apicomplexan

• Same as in dogs and cats, but also found in cows, sheep and goats​

• Main cause of enteritis in cows​

• Zoonotic

How do apicomplexans reproduce?

Apicomplexans can reproduce sexually using gametes or asexually through schizogony.

Trypanosoma cruzi

• Flagellate

• Same as in dogs and cats, but also found in cows, sheep and goats​

• Zoonotic

• Extracellular banana-shaped trypomastigote swims in blood​

• Non-motile cyst stage is called amastigote– can be found in cardiac muscle, esophagus, etc.​

• Diagnosed by blood smear

Babesia bigemina

• Same as in dogs and cats, but different species also found in cows, sheep and goats​

• Can be detected by PCR

Tritrichomonas foetus

• Flagellate

• Prepuce of bulls and vagina, cervix and uterus of cows, spread through herd by bull​

• Found: Worldwide but rare where artificial insemination is used​

• Can affect developing calf or cause infertility, low pregnancy rates and extending calfing season​

• Can be found in aborted calf fetus stomach​

• Washings of bull and cow can be centrifuged and sediment used to make a smear looking for motile flagellates​

• Bulls can be infected for life, cows tend to get over it if on sexual rest for 3-4 months

Horse protozoans

• Flagellates: Giardia Assemblage E​

• Ciliates: Usually mutualistic like ruminants​

• Apicomplexans: ​

  • Eimeria leuckarti​

  • Host: Horse​

  • Found: Worldwide​

  • Usually asymptomatic, but can cause intestinal inflammation​

  • Can be seen in saturated salt or sugar solution floats or in sediment​

  • Largest of all coccidians at 55 x 85 um, dark brown oocyst, single micropyle

Theileria equi and Babesia caballi

• Apicomplexan

• Host: Horses​

• Transmitted by tick​

• Not zoonotic​

• Pear, round or oval trophozoites 2-4um found inside RBC​

• T. equi can be found in fours inside RBC like a maltese cross​

• B. caballi is usually found in pairs at right angles inside RBC

Klossiella equi

• Apicomplexan

• Host: Horse​

• Adults in kidney​

• Found: Worldwide​

• Ingestion of oocysts in urine​

• Not zoonotic​

• Nonpathogenic in healthy horses

Sarcocystis neurona

• Host: Horse (aberrant) ​

• Schizogons (asexual stage) found in nervous system​

• Cause of infection: Ingestion of oocysts from opossum feces​

• Causes Equine protozoal myeloencephalitis​

• Destruction of neurons causes ataxia, weakness, stumbling, muscle wasting, disorientation video​

• Can resemble wobbler syndrome, herpes infection, rabies, West Nile virus, Eastern Equine encephalitis​

• Diagnosis is by tissue section post-mortem, but antibodies can detect exposure and PCR can be used on CSF

Swine protozoans

Ciliates:​

• Balantium coli​

  • Same as in dogs and cats​

  • Zoonotic​

Apicomplexans: ​

• Cystoisospora suis​

  • Same as in dogs and cats​

  • Mostly in piglets​

• Cryptosporidium sp.​

  • Same as in dogs and cats​

  • Zoonotic

Giardia psittaci

• Flagellate

• Host: Birds​

• Adults: intestinal mucosa​

• Cause of infection: Ingestion of oocysts​

• Most common protozoan in pet birds​

• Cockatiels, budgerigars, lovebirds​

• Voluminous, chunky feces like pea soup​

• Can cause allergic skin conditions in cockatiels

Histomomas meleagridis

• Flagellate

• Host: Turkeys, chickens, pheasants​

• Adults in liver​

• Cause of infection: Ingestion of Heterakis gallinarum ova or direct ingestion of eggs​

• Causes Infectious enterohepatitis, more commonly called Blackhead disease

Ichthyhophthirius multifiliis

• Ciliate

• Host: Freshwater and ornamental fish​

• Skin, gills, fins, eyes​

• Causes “Ich” or Ichthyophthiriasis​

• Tiny white spots all over the body​

• Visible with naked eye at 100-1000um