Studbook nr. 5, December 2008

EUROPEAN STUDBOOK CROWNED PIGEONS
5.7 Health
In this paragraph a couple of examples will be given about infections that occur in crowned
pigeons. Three cases will be illustrated in which crowned pigeons died unexpectedly or get
infected with parasites as well as possible causes. In many cases infections can be prevented by
taking precautionary measures.
Toxoplasmosis
Toxoplasma gondii has a worldwide distribution and is a common disease in crowned pigeons.
Virtually all vertebrate species are susceptible to infection (Garell, 1999). Domestic and exotic
felids are the only known definitive hosts of this parasite and as such are the only animals capable
of completing the enteroepithelial life cycle of the parasite and shedding oöcysts in their faeces
(Dorrestein et al, 2002).
In 2001 four Scheepmaker’s crowned pigeons (Goura scheepmakeri sclaterii) housed in the
same enclosure died unexpectedly within 4 days. All birds were in good to excellent condition and
most birds still had food in the proventriculus. During the post mortem, toxoplasma-like organisms
were seen in the lungs, liver, spleen and intestines. Infection through contact with cat faeces of
these pigeons could be in consequence of the leaves collected in the zoo for breeding purposes. But
also food polluted with cat faeces can often not be excluded (Dorrestein et al, 2002).
Sticktight flea
A 12-year old female Victoria crowned pigeon acquired from a private aviculturalist, was
diagnosed with a flea infestation during a quarantine examination. The fleas were embedded
around the face and throat and were identified as sticktight fleas (Echidnophaga gallinacea).
Although this parasite has the potential to induce morbidity and mortality, no feather loss, localized
dermatitis or anaemia were noted in response to the ectoparasitism. The infestation was treated
with manual removal of fleas combined with topical malathion dusting and environmental
treatment. Subsequent recheck exams did not reveal any fleas on this pigeon or on any of the other
birds housed in the same room (Zoltan et al., 2007).
This case illustrates the importance of quarantine procedures for newly acquired birds as
part of responsible captive management of a large, multispecies bird collection (Zoltan et al.,
2007).
Sarcocystis
Three Victoria crowned pigeons housed in a totally enclosed free-flight tropical exhibit died within
9 days of each other without showing signs of illness. No significant medical problems had been
noted with the birds. The horticulture department had placed new soil from an outdoor source
located on zoo grounds in several areas of the building 10 days prior to death of the first bird.
Immunohistochemical staining identified a Sarcocystis falcatula-like parasite in all three birds
(Suedmeyer et al., 2001). Sarcocystis species are coccidian parasites and are ingested by the
intermediate host.
It is suspected that new exhibit soil contaminated with faeces from the Virginia opossum
(Didelphis virginiana) was the source of the infective sporocysts. To help prevent future infections,
outdoor horticulture soil should not be placed directly in animal exhibits. The deaths of these three
birds documents the possibility of indoor infections with Sarcocystis falcatula-like organisms,
which have been previously reported only in outdoor aviaries. Veterinarians and zoo professionals
should be aware that infection with Sarcocystis falcatula can occur in totally enclosed aviaries
(Suedmeyer et al., 2001).
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