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| − | <big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big>
| + | {{OpenPagesTop}} |
| − | | + | ==Stages of Parturition== |
| − | <big><center>[[Reproductive_System#Parturition|'''BACK TO PARTURITION''']]</center></big>
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| | + | *Stage 1: this is the preparatory stage, starting at the onset of regular uterine contractions followed by cervical dilatation and the foetus assuming the correct disposition for passage through the birth canal. |
| | + | *Stage 2: the expulsive stage, characterised by the onset of abdominal contractions which together with uterine contractions lead to foetal expulsion |
| | + | *Stage 3: separation and expulsion of the foetal membranes. In polycotous species second and third stages are often inter-mixed. |
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| | + | The following table summarises the normal time taken to progress through the stages of parturition in different species. |
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| | | '''Stage 2: Foetal Expulsion''' | | | '''Stage 2: Foetal Expulsion''' |
| | | 12-30 minutes | | | 12-30 minutes |
| − | | 30-60 minutes | + | | 30 minutes - 4 hours |
| | | 30-120 minutes | | | 30-120 minutes |
| | | 150-180 minutes | | | 150-180 minutes |
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| − | | + | The step in the reproductive process that immediately precedes lactation, uterine involution and return to cyclicity. It is initiated by the foetus and involves a complex cascade of endocrine events. Parturition is the process by which the conceptus (foetus, placenta and placental membranes) is expelled from the [[Uterus - Anatomy & Physiology|uterus]]; this requires [[Cervical Softening - Anatomy & Physiology|cervical softening]],[[Uterine Contraction - Anatomy & Physiology|coordinated myometrial contractions]] and contraction of abdominal muscles |
| − | Parturition is the Process by which the conceptus (foetus, placenta and placental membranes) are expelled from the [[Female_Reproductive_Tract_-The_Uterus_-_Anatomy_%26_Physiology|Uterus]] requires: | + | to occur |
| − | * [[Parturition - Cervical Softening - Anatomy & Physiology|Cervical Softening]]
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| − | * [[Parturition - Coordinated Myometrial Contraction - Anatomy & Physiology|Coordinated Myometrial Contraction]]
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| − | * Voluntary contraction of abdominal muscles
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| − | = Stage 3: Placental Expulsion =
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| − | In most species, expulsion of foetal membranes quickly follows expulsion of the foetus.
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| − | * After the birth of the young, regular abdominal contractions largely cease.
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| − | * Myometrial contractions persist.
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| − | ** Decreased amplitude, but become more frequent and less regular.
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| − | ** Important for dehiscence and expulsion of foetal membranes.
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| − | * Waves of contractions from uterus to the cervix persist.
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| − | ** Act in a peristaltic fashion in the cow and sow in the reverse direction.
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| | == Placental Changes == | | == Placental Changes == |
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| | * Open endometrial crypts | | * Open endometrial crypts |
| | * Foetal villi have shrunk due to the escape of blood from the foetal side of the placenta when the umbillical cord ruptures. | | * Foetal villi have shrunk due to the escape of blood from the foetal side of the placenta when the umbillical cord ruptures. |
| − | * Myometrial contractions aid exsanguination of the placenta. | + | * [[Uterine Contraction - Anatomy & Physiology|Myometrial contractions]] aid exsanguination of the placenta. |
| | * Separation of foetal membranes. | | * Separation of foetal membranes. |
| | * Apex of the allantochorionic sac becomes inverted. | | * Apex of the allantochorionic sac becomes inverted. |
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| | ** Not the mare or camelids. | | ** Not the mare or camelids. |
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| − | = Parturition Behaviour = | + | == Placental Expulsion == |
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| − | == Mare ==
| + | In most species, expulsion of foetal membranes quickly follows expulsion of the foetus. |
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| − | === Stage 1 ===
| + | * After the birth of the young, regular abdominal contractions largely cease. |
| − | | + | * Myometrial contractions persist. |
| − | * Mammary hypertrophy, waxing of the teats and possible escape of milk from the glands. | + | ** Decreased amplitude, but become more frequent and less regular. |
| − | * Patchy sweating behind the elbows and around the flanks.
| + | ** Important for dehiscence and expulsion of foetal membranes. |
| − | ** Commences ~4 hours before the birth of the foal and increases as the stage progresses.
| + | * Waves of contractions from uterus to the cervix persist. |
| − | * Yawns
| + | ** Act in a peristaltic fashion in the cow and sow in the reverse direction. |
| − | * No indication of pain.
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| − | * Food is taken readily
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| − | * Respirations are normal
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| − | * Pulse is ~60
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| − | * Body temperature may become slightly subnormal (36.5-37◦C).
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| − | * Restlessness, wanders aimlessly.
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| − | * Tail is frequently raised or held to one side.
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| − | * May swish the tail or slap it against the anus.
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| − | * Kicking of the abdomen
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| − | * Towards the end of this stage:
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| − | ** Crouching
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| − | ** Straddling of hindlimbs
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| − | ** Going down on knees or sternum and rising again
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| − | ** Glancing at flank
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| − | * This stage terminates with the rupture of the allantochorionic membrane and the escape of allantoic fluid from the vulva.
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| − | ** No visible straining during this period.
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| − | | |
| − | === Stage 2 ===
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| − | * Abrupt onset, lasts~17 minutes
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| − | * Appearance of the amnion or commencement of forceful straining
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| − | ** Not much delay between them, often coincide.
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| − | * Soon after straining begins, the mare goes down.
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| − | * Lies on her side with the limbs extended
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| − | ** Generally remains in this position until the foal is born.
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| − | * Transperent blue/white 'water bag' (amnion) visible at the vulva
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| − | * Quickly followed by the appearance in it of a digit.
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| − | * Straining at regular intervals.
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| − | ** Each comprises 3/4 powerful expulsive efforts followed by a period of rest. | |
| − | ** Generally 3 minutes long | |
| − | * One forelimb procedes the other by 7-8cm
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| − | ** One elbow passes through the pelvic inlet before the other preventing minimal obstruction.
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| − | * Head is usually in the oblique position, but may be transverse with the cheek lying on the limbs.
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| − | * Greates and longest effort is with birth of the head.
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| − | * After expulsion of the foal, the mare may remain on her side exhausted for up to 30 minutes.
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| − | * Umbillical cord is intact when the foal is born.
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| − | ** Subsequently ruptures 5-8cm below the belly due to movement of the mare or foal.
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| − | * Foal is usually born within the amnion, which is ruptured by movements of the forelegs. | |
| − | * Lower portions of the hindlimbs often remain within the vagina for minutes after the rest of the foal is born. | |
| − | | |
| − | === Stage 3 ===
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| − | * Membranes expelled quickly after the birth of the foal.
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| − | * Usually within 3 hours.
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| − | * Duration of stage 3 is ~30 minutes.
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| − | * Afterbirth is expelled by myometrial contractions with no straining.
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| − | == Cow ==
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| − | === Stage 1 ===
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| − | * Lasts ~6 hours
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| − | * Relaxing of pelvic ligaments.
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| − | * Mammary secretions change from transparent,honey-like to opaque, cellular colostrum.
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| − | * Body temperature subnormal by ~0.6◦C.
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| − | * Parturition will begin 12 hours after complete relaxation of the posterior borders of the sacrosciatic ligaments.
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| − | * Heifers may show signs of abdominal pain for up to 24 hours before the cervix is fully dilated.
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| − | * Occasional straining may occur.
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| − | * Picks at feed, irregular rumination
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| − | * 'Lowing'
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| − | * Kicking of the abdomen
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| − | * Restless, may stand with her back arched and tail raised.
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| − | ** May go down and rise again frequently
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| − | * Pulse rate often increased to 80-90.
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| − | | |
| − | === Stage 2 ===
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| − | * Lasts 30 minutes - 4 hours
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| − | ** Longer in heifers than in cows
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| − | ** Male calves take longer to be born
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| − | * Onset marked by the appearance of the amnoin ('water bag') at the vulva.
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| − | * Less frequent straining
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| − | * Remains standing at first
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| − | * During passage of the head through the vulva, the cow normally goes down and remains recumbent until the calf is born.
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| − | * May lie on her side or in sternal recumbency.
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| − | * Placental separation occurs more slowly than in the mare.
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| − | * Umbillical cord of the calf is shorter than in the foal and generally ruptures as the calf falls from the vulva.
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| − | | |
| − | === Stage 3 ===
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| − | * Expulsion of the foetal membranes usually occurs ~6 hours after the birth of the calf.
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| − | ** After 24 hours consider a pathological cause for retained placenta. | |
| − | * Cow will eat the foetal membranes.
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| − | == Ewe ==
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| − | == Sow ==
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| − | === Stage 1 ===
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| − | === Stage 2 ===
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| − | === Stage 3 ===
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| − | == Bitch ==
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| − | === Stage 1 ===
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| − | * Lasts ~ 12 hours
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| − | * Prepares the bed
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| − | * If carrying one pup, the onset of lactation coincides with parturition.
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| − | * If carrying multiple pups, milk may be expressed from the teats several days prior to the onset of parturition.
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| − | * Body temperature subnormal by at least 1.2◦C within 24 hours before the onset of labour. | |
| − | * Restless
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| − | * Indifferent to food
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| − | * Panting | |
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| − | === Stage 2 ===
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| − | * Depends upon the number of foetuses, but usually lasts ~6 hours.
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| − | * Straining indicates the onset of the second stage.
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| − | * Bitch remains in her bed in sternal recumbency
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| − | * 'Water bag' of the first foetus appears at the vulva, and attains the size of a golf ball.
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| − | * Bitch licks the vulva vigorously and usually ruptures the 'water bag'.
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| − | * Delivery of the head requires the greates effort, once this is bord the rest of the foetus follows easily.
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| − | * Expulsion of the first foetus may take up to 1 hour.
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| − | * Umbillical cord is intact at birth, the mother will soon bite it away.
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| − | * Bitch rests for a time after the birth of the first puppy.
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| − | ** Lies licking the puppy, which soon begins to suckle.
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| − | ** Pays frequent attention to the vulva and licks any discharge.
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| − | * Foetal membranes generally voided in 10-15 minutes and eaten by the bitch.
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| − | * Straining recommences after a delay of 30 minutes - 2 hours.
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| − | * Effort and time required for subsequent deliveries is usually less than the first.
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| − | * May rest in between subsequent deliveries, but may not. The period of rest is also very variable.
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| − | * Puppies tend to be expelled from alternate horns (unlike the sow).
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| − | * Expulsion of foetal membranes is also irregular, they may come out individually, or the next puppy may be born with the membranes of its predeccessor around its neck.
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| − | === Stage 3 ===
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| − | * Membranes of the last foetus are expelled with it or shortly afterwards.
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| − | * Discharge is dark green in colour.
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| − | ** Due to breakdown of the marginal haematoma, blood pigment biliverdin escapes.
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| − | == Cat ==
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| − | During the last week of pregnancy, the queen seeks a nesting area. This is usually a quiet, undisturbed spot but some house cats will demand more human contact.Mammary development becomes noticable in the last week of pregnancy, especially in maiden cats. Rectal temperature may fall a few days before parturition, but this is not a reliable indicator.
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| − | === Stage 1 ===
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| − | * Restless
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| − | * Frequently visits the site for kittening
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| − | * Occasionally lies down and will strain unproductively.
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| − | === Stage 2 === | + | == Parturition Behaviour == |
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| − | * Straining in lateral recumbency.
| + | === [[Parturition Behaviour - Mare|Mare]] === |
| − | * Rapid expulsion of kittens with a short interval between each birth.
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| − | * Parturition usually complete within a few hours.
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| − | * If the queen is alarmed, this may disrupt the pattern and she may move the kittens to a new area before parturition resumes.
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| − | * Soon after birth the kittens begin to suckle.
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| − | === Stage 3 === | + | ===[[Parturition Behaviour - Cow| Cow]] === |
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| − | * Placentae usually expelled still attached to the foetus or shortly afterwards.
| + | ===[[Parturition Behaviour - Ewe| Ewe]] === |
| − | * Consumed by the queen.
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| − | * Breakdown of marginal haematoma releases biliverdin, giving the discharge a brownish colour.
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| | + | ===[[Parturition Behaviour - Sow| Sow]] === |
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| | + | ===[[Parturition Behaviour - Bitch| Bitch]] === |
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| | + | ===[[Parturition Behaviour - Cat| Cat]] === |
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| − | <big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big>
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| | | | |
| − | <big><center>[[Reproductive_System#Parturition|'''BACK TO PARTURITION''']]</center></big>
| + | {{OpenPages}} |
| | + | [[Category:Parturition]] |
| | + | [[Category:Bullet Points]] |