Trichomoniasis (Flagellate Infection) in Birds (with special reference to Waterfowl)

Disease Summary

• Protozoal disease of the upper respiratory and alimentary tracts.
• Most commonly known as a disease of the crop in pigeons.

Alternative Names (Synonyms)

• Trichomonas infection
• Frounce (in raptors)
• Canker (in pigeons)

Disease Type

Infectious/Non-Infectious Agent associated with the Disease

• Flagellated protozoan Trichomonas gallinae; in waterfowl also Tetratrichomonas anatis and Tetratrichomonas anseri (B24)
• Several Trichomonas spp. have been found in birds. (B24, B48.20.w20)

Further information on Disease Agents has only been incorporated for agents recorded in species for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Only those agents with further information available are linked below:

Infective "Taxa"

• Trichomonas spp.
• Tetratrichomonas spp.

Non-infective agents

Physical agents

References

Disease Author

Major References / Reviews

Code and Title List

Other References

Code and Title List

Detailed Clinical and Pathological Characteristics

• May or may not be general illness (not obvious illness with mild forms)
• Dribbling of saliva
• Regurgitation of food
• Difficulty in swallowing
• Sometimes laboured breathing.
• May be visible or palpable swelling of the crop.
• Weight-loss, emaciation.
• Droppings may be fluid and have a sour odour.
• Rarely, acute death in adults from involvement of large blood vessels.
• In squabs may be wasting and sudden death.

(D48, B197.14.w14)

1) Upper gastro-intestinal tract infection: Weight loss, listlessness, anorexia and sometimes dyspnoea (B11.34.w2, B37.x.w1).

2) Upper respiratory tract infection: Coughing, sneezing and swelling of infra-orbital sinuses (J6.26.w1).

3) Lower gastro-intestinal tract infection: Diarrhoea, emaciation (J6.26.w1)

Incubation

Mortality / Morbidity

Pathology

• Typically, mouth, nasal cavities, oesophagus or crop lesions.
  • Mouth: irregular yellow plaques on mucous membranes.
  • Mouth lesions may be small or sufficiently large to form caseous masses invading the roof of the mouth and even the sinuses.
  • Pharynx, oesophagus, crop:
  • Initially small, whitish to yellowish caseous nodules.
  • May develop to thick necrotic masses which are easily detachable from the underlying surface.
• May also affect the liver and umbilical area of squabs, forming "yellow button" lesions.
• (D48, B197.14.w14)
• No macroscopic lesions with infection with low virulence strains (B197.14.w14).

2) Upper respiratory tract infection: muco-fibrino-purulent sinusitis.
Histopathology: hyperplasia of mucous cells in epithelia of infraorbital sinuses, nose, trachea, with excess mucofibrinous exudate in lumen, containing protozoa, desquamated epithelial cells, heterophils and smaller numbers of mononuclear cells and erythrocytes. (J6.26.w1).

3) Lower gastro-intestinal tract infection: catarrhal inflammation of lower small intestine, excess mucus in lower small intestine.
Histopathology: Increased goblet cells and excess mucus secretion, associated with pyriform protozoa in intestinal lumen and crypt lumens. Marked plasma cell and lymphocyte infiltration of small intestinal lamina propria (J6.26.w1)

Human Health Considerations

Disease / Agent has been reported in either the wild or in captivity in:

• Naturally occurring Trichomoniasis has been reported in pigeons and raptors. (B48.20.w20)
• Found particularly in pigeons, and has been reported in the turkey, chicken, hawk, mourning dove, and golden eagle. (B24, D46)
• Mule ducks (Muscovy x mallard, Cairina moschata x Anas platyrhynchos) (J6.26.w1).

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken).

Host species with further information available are listed below:

WATERFOWL Host Species List

• Anas platyrhynchos domesticus x Cairina moschata domesticus - Mule duck

Disease / Agent has been specifically reported in Free-ranging populations of:

• Naturally occurring Trichomoniasis has been reported in pigeons and raptors. (B48.20.w20)

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken).

Host species with further information available are listed below:

WATERFOWL Host Species List

General Information on Environmental Factors/Events and Seasonality

Regions / Countries where the Infectious Agent or Disease has been recorded

Regions / Countries where the Infectious Agent or Disease has been recorded in Free-ranging populations

General Information on Investigation / Diagnosis

• Clinical signs and epidemiology may be suggestive.
• Lesions are easily removed from the underlying membrane without causing bleeding (unlike avian pox lesions)
• Post mortem examination lesions are characteristic but not sufficient for definite diagnosis
• Definitive diagnosis by microscopic examination of fresh smears from live or freshly dead birds:
  • Collect sample e.g. using a swab from the crop, immediately suspend in a drop of phosphate-buffered saline on a cover slip. Examine at x100 magnification for wriggling flagellate parasites.
• (D48, B197.14.w14)

•  Diagnosis by examination of fresh (within 30-60 minutes) oesophageal smear, infraorbital sinus exudate or intestinal contents (depending on site of infection) in isotonic saline for highly motile protozoa with undulating membrane and flagella. N. B. (J6.26.w1, B11.34.w2, B12.54.w2, B37.x.w1).
• Staining (Liu's method) allows full description: pear shaped, 12-20µm by 8-12µm, with nucleus, four anterior flagellae, backward-directed trailing flagellum, a pelta, clearly visible axostyle, and an undulating membrane (J6.26.w1).

• Physical Examination - General
• Necropsy - General
• Chapter 2 - B36 Field Manual of Wildlife Diseases - Specimen Collection and Preservation
• Chapter 3 - B36 Field Manual of Wildlife Diseases - Specimen shipment
• Appendix A - B36 Field Manual of Wildlife Diseases - Sample specimen history form

Similar Diseases (Differential Diagnosis)

Specific Medical Treatment

• Metronidazole 1g/litre drinking water for five days (D48, B197.14.w14).
• Ronidazole, 100-200mg/litre drinking water for five days (B197.14.w14).
• Dimetridazole 400mg/litre drinking water for three days (B197.14.w14).

• Treatment and Care - General

General Nursing and Surgical Techniques

• Treatment and Care - General

Preventative Measures

WATERFOWL

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Environmental and Population Control Measures

• For wild birds such as "garden birds".
  • Move feeding stations regularly, avoid feeding at the same site continuously.
  • Avoid using suspended feeders with sills on which food particles and droppings may collect
  • Clean up discarded feed and droppings from under suspended feeders and bird tables regularly e.g by sweeping, and dispose of hygienically (incineration is ideal).
  • Brush bird tables or other surfaces used for feeding daily.
  • Thoroughly clean bird feeders/tables regularly (as appropriate for speed of build up of droppings) and daily during a disease outbreak.
  • Wash or soak feeders/tables using a 5% sodium hypochlorite solution or a safe disinfectant (e.g. Tamodine-E, Vetark), followed by thorough rinsing.
• (D48)
• For raptors, if pigeons are used as food they should be inspected carefully and preferably frozen before use as this kills the parasites. (B156.16.w16)

• Reduce stocking densities at wild bird feeding stations by e.g. reducing food quantity supplied (D48)

• Preventative Medicine for Birds - General
• Environmental and Population Management - General