Disorders of the Reproductive System in Poultry

8/9/2019 Disorders of the Reproductive System in Poultry

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Disorders of the Reproductive System in Poultry

Cystic Right Oviduct in Poultry:

Fluid accumulation in the vestigial right oviduct is a common fnding in hens.

The abdominal cyst is flled with clear uid and is attached to the right sideo the cloacal wall. The cyst may vary in size rom barely perceptible to 15–

! cm in diameter. "n increased incidence has been seen in oc#s ater

inectious bronchitis virus outbrea#s. $viductal cysts are a necropsy fnding

that rarely% i ever% a&ect oc# perormance.

Defective or Abnormal Eggs in Poultry:

'ost (ridged%) (sunburst%) (slab*sided%) sot*shelled% or double*shelled eggs

are the result o eggs colliding in the shell gland region o the oviduct when

an ovum +yol#, is released too soon ater the previous one. -ecropsy

eaminations have demonstrated that two ull*sized eggs can be ound in the

shell gland pouch. "s the second egg comes in contact with the frst%

pressure is eerted% disrupting the pattern o mineralization. The frst egg

ac/uires a white band and chal#y appearance% while the second egg is

attened on its contiguous surace +ie% slab*sided,. 0impled or rough eggs

may have been retained too long in the shell gland. lood spots result when

a ollicle vessel along the stigma ruptures as the ovum is being released.

'eat spots occur when a piece o ollicle membrane or residual albumen

rom the previous day is incorporated into the developing egg.

'any abnormalities appear to have no specifc cause% but the incidence is

much higher in hens sub2ected to stressul management conditions% rough

handling% or vaccination during production. " signifcant increase in the

number o sot*shelled eggs is also common as a result o viral diseases such

as inectious bronchitis% egg drop syndrome% and -ewcastle disease.

3mall eggs with no yol# orm around a nidus o material +residual albumen,

in the magnum o the oviduct. 3mall eggs with reduced albumen and eggs

with deective shells may be the result o damage to the epithelium o the

magnum or shell gland.

4ery rarely% oreign material that enters the oviduct through the vagina +eg%

a roundworm, may be incorporated into an egg.

Egg-ound or !mpacted Oviducts in Poultry:



" ully ormed egg may lodge in the shell gland or vagina because the egg is

too big +eg% double*yol#ed, or because o hypocalcemia% calcium tetany% or

previous trauma +usually pec#ing, to the vent andor vagina that obstructs

oviposition. This condition may be more prevalent in young hens that are

brought into production beore body development is ade/uate or in hens that

are overweight or obese. 6t occurs more oten during spring and summer

months because o overstimulation o birds by increasing light intensity and

day length% which can be compounded by rapid increases in the amount o

eed andor ecessive protein +lysine,. This is a medical emergency in pet

birds but is usually recognized only during necropsy in commercial poultry.

7hen impaction occurs% eggs that continue to orm create layers o albumen

and yol# material% and the oviduct becomes very large. 3ome eggs are

reued to the abdominal cavity +abdominal laying,% and a&ected hens

assume a penguin*li#e posture.

Egg Peritonitis in Poultry:

8gg peritonitis is characterized by fbrin or albumen*li#e material with a

coo#ed appearance among the abdominal viscera. 6t is a common cause o

sporadic death in layers or breeder hens% but in some oc#s may become the

ma2or cause o death beore or ater reaching pea# production and give the

appearance o a contagious disease. 6t is diagnosed at necropsy. 0eritonitis

ollows reverse movement o albumen and 8scherichia coli bacteria rom the

oviduct into the abdomen. 6 the incidence is high% culture should be done to

di&erentiate between 0asteurella +owl cholera, or 3almonella inection."ntibiotic treatment o peritonitis caused by 8 coli inections is usually

ine&ective. 'anagement o body weight and uniormity% reproductive

development +ovary ollicle growth and maturation,% and drin#ing water

sanitation are the best preventive strategies.

7hen hens have too many large ovarian ollicles% a problem described as

erratic oviposition and deective egg syndrome +8$983, is seen in broiler

breeders. This condition is accompanied by a high incidence o double*yol#ed

eggs% prolapses o the oviduct% internal ovulation% andor internal laying that

oten results in egg peritonitis and mortality. 8$983 is prevented by avoidinglight stimulation o underweight pullets too early and by ollowing guidelines

or body weight and uniormity% and lighting recommendations or each

breeder strain. $verweight hens may also have a higher incidence o erratic

ovulations and mortality associated with egg peritonitis.

"alse #ayer $Poultry%:



These hens ovulate normally% but the yol# is dropped into the abdominal

cavity rather than being collected by the oviduct because o inammation

and resulting obstruction o the oviduct ater inection with 8scherichia coli

or 'ycoplasma gallisepticum. The yol# is absorbed rom the abdominal

cavity. The hen loo#s li#e a normal layer but does not produce eggs.

:ypoplasia o the ovary and oviduct has been associated with inectious

bronchitis virus inections +see 6nectious ronchitis, at an early age +1–

w#,. "tresia or even atrophy o the ovary are caused by severe stress%

chronic inections% insu;cient eed inta#e% inade/uate eeder space% and

eed reusal due to mycotoins in the eed.

&ypocalcemia' Sudden Death' Osteoporosis' or Cage #ayer "atigue

$Poultry%:

0ullets or hens with insu;cient dietary calcium% phosphorus% or vitamin 9<

may die suddenly or be ound paralyzed rom hypocalcemia while shelling anegg. This may be associated with high production and withdrawal o calcium

rom bones or egg shell production% in which case the main lesion may be

osteoporosis. "t necropsy% there is an egg in the shell gland and the ova are

active and ully developed. There are no other lesions% although medullary

bone may be lac#ing. 0aralyzed hens respond to calcium 64% and this

response may be useul in diagnosis.

$steoporosis is a ma2or cause o death in high*production oc#s. :ens with

osteoporosis may show similar signs at necropsy% or the ova may be

regressing with no egg in the oviduct. The emur is always ragile% and

medullary bone is always absent in osteoporosis. These hens may also

respond to calcium 64 i there are no ractures o the legs or vertebrae. The

use o large particle size calcium +limestone% oyster shell, in the diet may be

benefcial. :igh rates o mortality due to ractures are common in birds

a&ected with osteoporosis. This situation is more common in broiler breeder

hens in slatted houses due to the trauma caused by 2umping on and o& the

slats. =uptured egg ollicles indicating trauma can be ound during necropsy

eamination o these birds.

" condition #nown as hypocalcemia or calcium tetany +paralysis, has been

seen in modern or high*yielding broiler breeder hens. 3igns such as panting%

spread wings% and prostration may be seen in the early morning hours

preceding paralysis and death by asphyia. >areul postmortem eamination

reveals a ully active ovary and the presence o a partially or ully ormed

egg in the shell gland in the absence o other lesions. This indicates that the



oviduct o emales% and live sperm can be retained or <–? w#. 7aterowl

have a rudimentary penis% and prolapse o the penis is occasionally reported

in dra#es. There is no treatment.

(eoplasia of the Reproductive System in Poultry:

The most re/uent tumor o the reproductive system is adenocarcinoma o

the oviduct. -eoplastic cells are shed rom tumors in the oviduct into the

abdominal cavity. They implant on the ovary% pancreas% and other viscera

and produce multiple% hard% yellow nodules. They may bloc# lymph return

and result in ascites. The incidence increases with age% and this tumor may

be a re/uent cause o death ater yr. "&ected hens are condemned at

processing.

@eiomyoma o the broad ligament is an estrogen*induced hypertrophy o the

smooth muscle o the broad ligament. 6t is benign and is an incidental fndingat necropsy or processing.

" variety o ovarian and testicular tumors has been described. 'are#As

disease +see 'are#As 9isease in 0oultry, is a common cause o tumors o the

ovary.

Oophoritis and Ovary Regression in Poultry:

=egression o the ovary may result in lea#age o ree yol# into the abdomen

+yol# peritonitis,B this rarely causes death ecept when yol# material

migrates through the air sacs to the lung and causes oreign bodypneumonia. Free yol# is seen in many cases o acute illness% in2ury% or orced

molt. =egression o the ovary is re/uently caused by low body weight%

deliberate reduction o eed% overcrowding% or lac# o eeder space. 6nectious

diseases such as -ewcastle disease% owl cholera% pullorum disease% and

avian inuenza are #nown to cause this condition. 6t can also result rom

severe stress% which is oten accompanied by eather molt% emaciation% and

dehydration.

Prolapse of the Oviduct in Poultry:

7hen an egg is laid% the vagina everts through the cloaca to deliver the egg.

6 there has been in2ury to the vagina% such as rom a large or double*yol#

egg% or i the hen is at% the vagina may not retract immediately% leaving it

eposed or a short time. This may result in cannibalism +see >annibalism in

0oultry,. 7hen the protruding organ is pec#ed by other hens% the complete

oviduct and parts o the ad2acent intestinal tract may be pulled rom the

Disorders of the Reproductive System in Poultry

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