• Cause: motile protozoa, Spironucleus meleagridis (previously known as Hexamita meleagridis). Most commonly affects pheasants and partridge and turkeys.
• Signs: watery diarrhea, lethargy, depression, hunched posture with ruffled feathers, dehydration, death.
• Diagnosis: confirmation of parasite presence on microscopy of fresh, wet, duodenal or jejunal smears.
• Treatment: supportive: fluid and electrolyte therapy and enteral nutrition. Tetracyclines.
• Prognosis: fair to guarded, depending on severity of disease.

• Watery or frothy, yellow diarrhea.
• Lethargy.
• Depression.
• Hunched posture with ruffled feathers.
• Emaciation or rapid weight loss
• Anorexia.
• Dehydration.
• Convulsions.
• Comatose.
• Death.

• Dull, dehydrated birds with diarrhea.

• Rare in North America.

• Young birds in stressful situations.
• Highest mortality rate in birds aged 1-9 weeks old.

• Most commonly affects partridge, pheasant, quail, peafowl and turkeys.
• Natural infection has not been observed in chickens.

• Care with hygiene and wear appropriate gloves and PPEwhen handling gamebirds with diarrhea.

• Economically important disease of game birds.

• Motile protozoa Spironucleus meleagridis (previously known as Hexamita meleagridis).

Specific

• Stress: birds exposed to stressors, including inclement weather are particularly vulnerable.

• Research is ongoing into the lifecycle and pathophysiology of this parasite with a cystic stage being only relatively recently considering the decades of research into this parasite.
• Spironucleus cysts are the infective form.
• Parasite reduces absorption from the intestines resulting in watery diarrhea.
• Fecal-oral transmission, direct and indirectly through contaminated equipment and clothing.

• Incubation approximately range around 7 days.

• Fecal-oral transmission.
• Infective cysts excreted in feces.
• Survivors may become asymptomatic carriers.
• High morbidity up to 80%.
• Variable mortality from 1-50%.

Refereed papers

• Recent references from PubMed and VetMedResource.
• Lloyd S & Gibson J S (2006) Haematology and biochemistry in healthy young pheasants and red-legged partridges and effects of spironucleosis on these parameters. Avian Pathol Journal WVPA 35 (4), 335-340 PubMed.
• Wood A M & Smith H V (2005) Spironucleosis (hexamitiasis, hexamitosis) in the ring-necked pheasant (Phasianus colchicus): Detection of cysts and description of Spironucleus meleagridis in stained smears. Avian Diseases 49 (1), 138-143 PubMed.

Other sources of information

• Raftery A & Jones R (2019) Gastrointestinal Disorders. In: Manual of Backyard Poultry Medicine and Surgery. Eds: Poland G & Raftery A. BSAV, UK. pp 205-215.
• Carpenter J W & Marion C J (2018) Exotic Animal Formulary. Elsevier, USA.
• Carpenter J W & Christopher J M (2018) Exotic Animal Formulary. 5th edn. Elsevier, USA.
• Swayne D E (2013) Diseases of Poultry. 13th edn. Wiley-Blackwell, USA.
• Pattison M (2008) Ed Poultry Diseases. 6th edn. Elsevier/Butterworth-Heinemann, UK.

• National Animal Disease Information Service (online) Spironucleus (Hexamita) and Trichomoniasis in Game Birds. NADIS Animal Health Skills, UK. Website: www.nadis.org.uk.