|
|
The information below is adapted from information provided by Cornell University's Duck Research Lab.
Common Diseases of Ducks & Toxics
Duck Virus hepatitis
Duck virus hepatitis is a highly fatal contagious disease of young ducklings,
1-28 days of age. Ducklings are most susceptible at the younger ages and
gradually become more resistant as they grow older. The disease is rarely seen
in ducklings over 4 weeks of age. The onset of the disease is very rapid, it
spreads quickly through the flock and may cause up to 90% mortality. Sick
ducklings develop spasmodic contractions of their legs and die within an hour
in a typical "arched-backward" position. The liver is enlarged and
shows hemorrhagic spots. To prevent this disease, keep age groups isolated and
vaccinate breeder ducks with an attenuated live virus duck hepatitis vaccine
(to produce maternally immune ducklings).
Duck Plague (Duck Virus Enteritis)
Duck Virus Enteritis is an acute, contagious, highly fatal disease of waterfowl
caused by a herpes virus. This disease is most likely to affect mature ducks,
but is also seen in young ducks. Affected birds show sluggishness, ruffled
feathers, greenish-yellow diarrhea that is sometime blood-stained. Dead birds
often have blood-stained feathers around the vent and blood dripping from the
nostrils. Hemorrhages may be found in tissues throughout the body. Eruptive
lesions of the mucous lining of the esophagus and intestine are characteristic
signs of the disease. Necrotic plaques may be observed in the cloaca. Regular
immunization of breeder ducks with an attenuated live duck virus enteritis
vaccine provides adequate protection.
Riemerella Anatipestifer Infection
This bacterial disease of ducks is also known as Pasteurella Anatipestifer
infection, infectious serositis and New Duck disease. Anatipestifer infection
causes high mortality, weight loss and condemnation. In the acute form,
listlessness, eye discharge and diarrhea are commonly seen. Ducks show
incoordination, shaking of the head and twisted neck. Birds are commonly found
on their backs, paddling their legs. Typical lesions found in dead birds are
infected air sacs, membranes covering the heart and liver, and meningitis.
Preventive management and vaccination are effective means of control.
Penicillin, enrofloxacin and sulfadimethoxine-ormetoprim (0.04-0.08% in feed)
are effective in reducing mortality.
Avian Cholera
Avian cholera, also called fowl cholera, caused by the bacterium Pasteurella multocida is an important
disease of domestic ducks, and is an especially troublesome disease of ducks in
some parts of Asia. This disease is associated
with poor sanitation, and standing water in duck pens. Symptoms include loss of
appetite, mucous discharge from the mouth, diarrhea, and in breeder ducks,
labored breathing. Lesions found in dead birds include hemorrhages on heart
muscle, mesentery and abdominal fat. The liver is enlarged, copper colored and
friable (easily crumbled). Pinpoint whitish spots may be seen on the liver.
Good sanitation practices go a long way toward preventing this disease.
Sulfadimethoxine-ormetoprim (0.02-0.04%) and Chlortetracycline (0.044%). given
in feed are effective treatments.
Colibacillosis
This common infection of poultry caused by Escherichia coli., causes reduced hatchability, infection of
the yolk sac (omphalitis), a septicemia (bacterial invasion of bloodstream) in
ducks 2-8 weeks of age and salpingitis and peritonitis in breeder ducks. In
market ducks, E. coli. infection produces
lesions very similar to those seen in Riemerella anatipestifer infection (see above). Good sanitation and
management are important preventive measures. Sulfadimethoxine-ormetoprim
(0.04-0.08%) and chlorotetracycline (0.044%) in feed are helpful in controlling
this disease.
Aspergillosis
This condition occurs when ducks inhale spores produced by the mold (fungi)
Aspergillus (Aspergillus
fumigatus is the common species) that grows on damp straw or feed. These
inhaled spores cause multiple nodules or plaques in the lungs and air sacs.
Common signs include gasping, listlessness and dehydration. This disease is not
to be confused with aflatoxin poisoning described below. The best solution to
prevent aspergillosis is to avoid using moldy straw and preventing feed from
getting wet.
Toxins
Ducks are particularly susceptible to certain toxins, and in
some cases strikingly more than chickens or turkeys. Therefore, duck caretakers
must be especially diligent in preventing ducks from consuming or being exposed
to these toxins.
Aflatoxin poisoning
Molds (fungi) that grow on cereal grains and oilseeds before and after harvest
produce a number of toxins that are particularly harmful to ducks. By far the
most toxic of these substance is a group of toxins called aflatoxins.
Aflatoxins are produced by the molds Aspergillus flavus and Aspergillus parasiticus. Ducks are highly susceptible to these
toxins. Very small amounts will cause high mortality. Wet harvest conditions
encourage the growth of this mold.
Botulism
Ducks that have access to stagnant ponds or other areas where decaying organic
matter (animal carcasses, in particular) is found may consume toxins produced
by the bacterium Clostridium
botulinum. This happens when temperature and other conditions are right
for the growth of this anaerobic spore-forming bacterium. Botulism causes a
progressive flaccid (limp) paralysis of the neck (limberneck), legs and wings.
Affected ducks usually die in a coma within 24-48 hours.
Castor bean poisoning
Incidents of high death losses in wild ducks, due to consuming castor beans
(Ricinus communis) have been reported in Texas.
Castor beans contain ricin, a toxalbumin known to cause toxicity in humans and
domestic animals.
Rapeseed meal
Some older varieties of rapeseed meal contain erucic acid and goitrogens at
levels high enough to be harmful to poultry. Ducks are much more sensitive to
erucic acid than are chickens and turkeys. Genetically improved varieties of
rapeseed (Canola) contain much lower levels of these toxins. However even
Canola meals should first be tested in ducks before their use in duck feeds on
a large scale.
Insecticides, rodenticides
Duck keepers should take care not to use insect sprays or rodent poisons, that are
known to be harmful to ducks, in areas accessible to ducks. Some insect sprays
are highly toxic to ducks, such as parathion and diazinon. Always read the
directions on the insecticide container carefully before using around ducks.
Rat poisons that contain Warfarin, an anticoagulant, if consumed by ducks, can
cause them to bleed to death.
|
Defending against Predators
Protection against dogs, bobcats, coyotes, foxes, and larger birds.
|
