| PART FIVE
Disease patterns
Ducks, we are told "exhibit greater resistance to most diseases
and parasites than do most domestic fowl" (1). Because of this,
few drugs have been approved for ducks, so antibiotics are not routinely
given (2). According to the FSIS, if a drug is given it is done
through the feed (3). Feed medications are given to control the
common diseases of ducks: colibacillosis, fowl cholera, salmonellosis,
and necrotic enteritis (4).
Diseases
The North Carolina Cooperative Extension Service, part of North
Carolina State University College of Agriculture & Life Science
(5), list the following as descriptions of these diseases:
Colibacillosis - A common duck disease caused by the bacterium Escherichia
coli. E. Coli can cause embryonic and duckling mortality by infecting
the yolk sac. Most common is the infection of the digestive track
and air sacs. Infected ducklings appear droopy and listless and
exhibit diarrhea and ocular discharge.
Fowl cholera - Contagious disease of domestic ducks and other birds,
which is caused by the bacterium Pasteurella multocida. Sick ducklings
refuse feed and exhibit diarrhea and mucus discharge from the mount.
Mortality may be as high as 50%.
Salmonellosis - Another common duck disease caused by a variety
of serotypes of salmonella. Infected ducks are listless, dehydrated,
exhibit diarrhea, and show signs of incoordination and head tremors.
Mortality is about 10%.
Necrotic enteritis - Common infectious disease of breeder ducks
for which the exact cause is unknown. Infected ducks are weak and
unable to stand; and their digestive tracts are swollen and filled
with blood stained fluids. Mortality is high: approximately 40%.
Medicated feeds
According to the Food and Drug Administration, only the following
drugs have been approved for use in duck feed (6).
Albamix Feed Medication is used to control infectious serositis
and fowl cholera caused by Pasteurella anatipestifer and P. multocida,
which are susceptible to novobiocin - the product's main ingredient.
It is not used for laying ducks.
Aureomycin Type A Medicated Article is used for the control and
treatment of fowl cholera caused by Pasteurella multocida, which
are susceptible to chlortetracycline - the product's main ingredient.
It is not used with ducks producing eggs for human consumption.
Chlorachel 10, Chlorachel 20, and Chlorachel 35 are used for the
control and treatment of fowl cholera caused by Pasteurella multocida,
which are susceptible to chlortetracycline - the product's main
ingredient.
Protomone Thyroactive Casein is used to increase the rate of weight
gain and improved feathering in growing ducks.
Global diseases
World Poultry Misset (7) provides a list of poultry diseases which
can occur anywhere in the world. Those affecting ducks are in addition
to those described above and include the following:
Adenovirus - Associated with many diseases including respiratory
disease and viral arthritis.
Amyloidosis - Associated with infected lesions on the feet and amongst
adults in heavier strains of commercial ducks.
Ascites - More often associated with chickens, it made its first
appearance in birds kept at high altitudes. It is mostly caused
by increased oxygen demand resulting from too-rapid growth in combination
with restricted blood flow through the small capillaries in lungs
of birds selected for 'meatiness' (8).
Avian influenza - Believed to be spread by close contact. Results
in respiratory distress and depression.
Avian malaria - Similar to the human form of the disease.
Avian salmonellosis
Avian staphylococcus - Associated with a wide variety of diseases,
including arthritis and tenosynovitis.
Bacterial synovitis - An infection of the joints, tendons and surrounding
tissues resulting in lameness.
Fowl Pest (Newcastle disease) - Ducks show few signs of infection
even with virulent strains of fowl cholera but the disease can spread
via ventilation apertures into the environment. Vaccines are of
little effectiveness in overcrowded conditions where management
is poor and may even produce the disease.
Keratoconjunctivitis (Ammonia blindness). It is caused by ammonia
in concentrations of 170 ppm or more (9). Poorly managed, damp litter
in badly ventilated housing can be instrumental in triggering this
extremely painful disease, which can result in hemorrhages of the
conjunctiva and corneal ulcers. Damp litter is a major problem in
duck units (as litter is not cleaned out frequently enough) and
some U.S. producers tackle it by allowing only nipple drinkers or
by keeping ducks on wire flooring.
Yolk sac infection (Omphalitis). Often the result of poor conditions
in hatcheries, it can cause 100 percent mortality in the worst outbreaks
by infecting most organs.
Perosis (Slipped tendon) - a leg deformity in ducklings, causing
lameness.
Tibial dyschondroplasia. A skeletal deformity associated with rapid
growth and mineral imbalances.
Cloacitis (Vent gleet). An infection of the cloaca in breeding ducks
and drakes - occurs particularly "under dirty conditions of husbandry"
(10). Scarring can damage the vent, making egg laying and even defecating
impossible.
Visceral gout. Caused by renal failure, it results in swelling and
ulceration of the joints.
Starve out. This results when young or injured birds fail to recognize
or reach food and water points.
Rickets. A nutritional disorder caused by lack of certain minerals,
vitamins and trace elements.
Diseases of intensification
Birds have always suffered from a range of diseases and wild birds
are implicated in the spread of some disease. However, many of the
conditions above listed are the result of intensive farming methods.
The increasing popularity of duck meat both here and abroad will
inevitably cause an escalation in the incidence of these diseases,
guaranteeing large-scale suffering among the duck population. It
will also further accelerate the reckless overuse of antibiotics
which is already a potential human health problem.
Though killed while still young, the modern duckling will have had
time to endure much pain and discomfort before reaching the slaughterhouse.
It is likely that their entire life, no matter how short, will be
one of acute stress and perhaps disease and severe pain.
References (part five)
1. North Carolina Cooperative Extension Service,
North Carolina State University, College of Agricultural & Life
Science, Poultry Science Facts, Feeding Ducks, 4/90, 10/2/98. www.ces.ncsu.edu/depts/poulsci/techinfo/4Fact02.htm.
2. United States Department of Agriculture, Food
Safety and Inspection Service, Consumer Education and Information,
July 1996. www.fsis.usda.gov/oa/pubs/duckgooos.htm.
3. Ibid
4. North Carolina Cooperative Extension Service,
North Carolina State University, College of Agricultural & Life
Science, Poultry Science Facts, Feeding Ducks, 4/90, 10/2/98. www.ces.ncsu.edu/depts/poulsci/techinfo/4Fact02.htm.
5. Ibid
6. FDA (Food and Drug Administration) Approved Animal
Drug Products, Online Database System, March 2000.
7. World Poultry Misset (No. 7, Vol. 13, 1997)
8. Poultry Diseases, Ed. F.T.W. Jordan, Bailliere
Tindall, 1990, p39.
9. Cook, JKA et al., Diseases of Ducks, Poultry
Diseases, 1996
10. Ibid
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