Coccidiosis is an intestinal disease that is widely distributed among pigeons throughout
the world. Coccidia inhabit the small intestine of nearly all pigeons.
Pathogen:
Along with trichomonads, coccidia are the most commonly found protozoa in pigeons,
occurring in the form of two eimeria species: E.labbeana and E.columbarum. Both
species only infest pigeons. Coccidia form permanent stages (oocysts), which only
become infective after maturing in the environment.
Course of disease:
Following ingestion of the oocysts, their subsequent developmental stages damage the
intestinal wall. Within 4-7 days of infection, the pigeon starts to excrete oocysts
again.
There are two forms of coccidiosis:
The asymptomatic (or subclinical) form occurs most frequently. After ingesting small
quantities of oocysts for the first time, pigeons develop an immunity to infection due
to stimulation of endogenous defence mechanisms, without visibly succumbing to the
disease. With this protection, which is reinforced by constant ingestion of low levels
of oocysts, the birds live in a kind of equilibrium with the parasites, which also
protects them against severe intestinal disease.
The visible form of the disease with an acute course and severe generalised
disturbance - true coccidiosis - occurs when still unprotected young pigeons become
infected by ingesting large amounts of oocysts or when the immunity of older pigeons
is reduced or broken down by stress factors.
Symptoms of the disease:
Asymptomatic form:
Infested birds appear healthy, albeit rather less lively. The droppings are
sometimes rather soft.
Acute course:
Visibly affected pigeons produce malodorous, muco-aqueous, greenish and sometimes
bloody diarrhoea. They are listless, have puffed-up plumage and drink profusely,
with reduced feed intake.
Recognition of the disease:
Coccidial oocysts can be demonstrated by microscopic examination of faecal samples
(prepared according to the flotation method).
Asymptomatic form:
Only a small quantity of oocysts is identified in the faeces (finding = +).
Acute form:
The contents of the gut reveal moderate (finding = ++) or severe (finding = +++)
oocyst infestation.
Similar conditions:
Salmonellosis, E.coli infection, worm infestation.
| Coccidiosis |
