Coryza, commonly known as simply Coryza, is a bacterial disease of the
respiratory system that is highly contagious and largely incurable. Facial swelling, discharge from the eyes and
nose, and a characteristic offensive odor from this discharge are key signs of
a Coryza infection. This disease is
very serious and largely incurable since birds remain carriers. Depopulation is strongly recommended, however
since the bacteria does not survive long outside the host, after a few weeks
the flock can be repopulated. Treatment
is not very effective and must be combined with sound management.
Affects both wild and domesticated birds.
Pheasants & Guineas
Note: There is disagreement from
reputable sources as to whether Pheasants and Guineas actually contract IC, or
another disease with similar symptoms that has a different cause.
Where: Worldwide, with the vast majority (>90%)
in temperate climates during fall & winter months; occurrence is
infrequent, but more common in hobby and backyard flocks.
When: > 1 month; most frequently in adolescent
or mature birds
Why: Bacteria; Hemophilus
common cause is from the introduction of carriers to a flock.
by carriers via water, bedding or feed.
by airborne dust and exhaled droplets.
remain carriers. All birds within an
affected flock are considered carriers.
can be brought on by general stress or drafty coops which presumably compromise
the immune system.
infections, particularly other respiratory diseases are common.
Coryza can last much longer when infected simultaneously with Mycoplasma Gallisepticum (MG)
unpleasant odor from reddish nasal discharge
discharge is thick and sticky
one eye is stuck shut due to discharge
discharge from eyes
food & water consumption
growth in when illness lingers
Culling is recommended. Disease
may reoccur following treatment. Drugs
only are insufficient for control.
depopulation and repopulation is recommended.
from flocks that have been infected should never be taken to swaps, shows or
auctions. They should be culled, or the
flock should remain isolated.
flock management is crucial. If outbreak
occurs, depopulate, disinfect the coop & leave unoccupied for several weeks
before reintroduction of birds.
bacteria cannot last long outside the host, and is susceptible to
disinfectants, so depopulation followed by disinfection is the surest way to
Yes, but typically only used in commercial populations:
used in commercial flocks where prior outbreaks are recorded.
when introducing commercial layers into a flock.
Also Known As:
Observation of distinctive nasal discharge with offensive odor;
observation of facial swelling particular to Coryza; confirmation by blood
testing in a lab.
Diseases with similar symptoms:
cholera (also has swelling of the face and wattles)
head syndrome (ornithobacterosis)
Note: The characteristic offensive
odor of Coryza is key to identification.
Duration of symptoms: A few days, up
to 3 months.
Incubation: As little as a
few hours, up to 3 days.
Morbidity: High (>50%)
Mortality: Up to 50%, but
usually 20% or less.
Transmission to people:
No known cases.