The document discusses parturition, or birth, in domestic animals. It covers:
- The stages of labor, including preparation, fetal expulsion, and placental expulsion.
- Signs that labor is approaching in various species like cows, mares, and dogs.
- Theories on what initiates parturition, involving physical, biochemical, and neuroendocrine factors.
- Fetal changes that prepare it for life outside the womb, like lung and liver maturation.
- Species-specific details on the duration of labor stages in animals like cows, buffalo, mares, sheep, sows, dogs, and cats.
- Diagrams illustrating the sequence of birth events
Vet obst lecture 5 Parturition in domestic animals
1. Parturition in Domestic Animals
Prof G N PUROHIT
Head, Department of Veterinary Gynecology and Obstetrics,
College of Veterinary and Animal Science, Rajasthan University
of Veterinary and Animal Sciences, Bikaner, Rajasthan, India
2. Parturition: Delivery of fetus through the birth canal
on completion of gestation period
• Birth canal is formed by the uterus, cervix and vagina within
the pelvic bones and their attachments
• The muscular canal that forms from the uterus to the outside
of the body through which the fetus passes
during birth.
3. Pre-parturient Care
Shifting to calving boxes 1-2 months before calving
Mares need a quiet environment
Feeding Cows should be given a low energy high fiber diet
during gestation and anionic salts should be given if
they are fed fodder to which high K+ fertilizer has been added
Sheep twin fetus carrying animals should be fed high
energy feed.
Bitches 1.0 to 1.8% Ca and 0.8-1.6 % P in diet of late
pregnant bitches
Vaccines Tetanus vaccination of foaling mares
4. Vaccination of pregnant bitches
• Never use a live vaccine in a pregnant bitch: only use
registered 'safe' killed vaccines and registered 'safe'
intranasal vaccines.
Keep up to date with live vaccines in non-pregnant bitches
to avoid having to give vaccines to pregnant bitches.
5. • Killed parvovirus vaccines can be given 2 weeks or more
before the pups are due to be born (they should not be given
any closer to the time of birth than this) to increase the levels
of parvovirus antibodies in the colostrum. Maternal antibody
levels may persist in these antibody-enriched pups for up to
14 weeks and, depending on the vaccine type being given to
these pups, they may require preventative vaccinations for
up to 16-18 weeks of age before they are considered safe to
socialise.
6. • Newer vaccines are now available that overcome this
issue of maternal immunity, achieving full protection within
12 weeks of age.
• If using vaccination therapeutically, in order to achieve
high levels of immunoglobulin's (antibodies)in the
colostrum, vaccinate the pregnant bitch 2-3 weeks before
the pups are due to be born.
7. Vaccination of pregnant mares
• Vaccinations should be current, since infectious diseases can trigger
abortions.
• It is recommended that mares be vaccinated against EHV-1 in the 5th,
7th and 9th month of her pregnancy. In higher risk situations first
Rhinopneumonitis immunization be given at 3 months. Currently, there
are two killed virus vaccines approved for use in pregnant mares to
prevent EHV-1 abortion: Pneumabort-K® (Fort Dodge Animal Health,
Ft. Dodge, IA) and Prodigy® (Intervet, Inc., Millsboro, DE).
8. • Pregnant mares previously vaccinated against
tetanus: Vaccinate annually 4 to 6 weeks before foaling, both
to protect the mare should foaling-induced trauma or retained
placenta occur and to enhance concentrations of colostral
immunoglobulins.
• Pregnant mares unvaccinated against tetanus or of unknown
vaccinal history: Administer a 2-dose primary series of
tetanus toxoid with a 4- to 6-week interval between doses.
Revaccinate 4 to 6 weeks before foaling.
• TT 25-40 Lf Units IM
9. Sheep and goats
• Pregnant ewes should be vaccinated for clostridial diseases
(usually clostridium perfringins type C & D and tetanus) 4 to 6 weeks prior to
parturition.
• Vaccinated females will pass antibodies in their colostrum to their newborn
lambs via the colostrum. Ewes that have never been vaccinated or whose
vaccination status is unknown will require two vaccinations during late
gestation, 4 weeks apart. Ewes should not be vaccinated within two weeks of
lambing. This is not enough time to get antibodies in the colostrum.
• If the dam was not vaccinated for tetanus, the tetanus
Antitoxin should be given at the time of docking.
10. Can pregnant cows be dewormed?
• In the vast majority of cases, it is safe to deworm pregnant cattle.
... There are a few exceptions; an example is albendazole
(Valbazen), which restricts use in cattle during the first 45 days of
pregnancy.
• Pyrantel pamoate is safe to use in pregnancy and lactation and is
frequently used in these situations to minimize the
worm burdens of neonatal animals.
•
11. Deworming mares
• Most commercially available dewormers are safe for use in pregnant
mares, however, it is always recommended to check the product label
before administering a dewormer or any other product to a pregnant
mare.
• Last treatment should occur 4-6 weeks before her due date
• Many vets suggest to administer ivermectin
• dewormer to the mare within 12 h or foaling
• to avoid the passage of strongyles in milk that
• may cause diarrhea in new born foals.
12. Dogs
• Deworm the bitch prior to mating and then at 5 weeks and 8
weeks gestation. Make sure you use a good quality wormer
that is SAFE for pregnant/lactating bitches.
• Fenbendazole is considered a safe dewormer against
roundworms, hookworms, whipworms and giardia. This may
not stop the puppies from getting worms,
but at least It may decrease the amount
13. Sheep and goats
• It is a good idea to feed a coccidiostat to ewes during late
gestation. All sheep have coccidia in their GI tracts. Coccidiostats
disrupt the life cycle of coccidia; therefore, feeding a coccidiostat
will reduce the number of coccidia oocytes being shed into the
lambing environment.
• Deworming with an effective anthelmintic will help the ewe expel
the worms and reduce the exposure of
newborn lambs to infective worm larvae.
Albendazole should not be given to pregnant
ewes during first trimester of pregnancy.
14. Symptoms of approaching parturition
Cow Udder enlargement 4 months in heifers and
1-2 weeks before parturition in cows
Vaginal discharge 7 months
Relaxed ligaments 24 - 48 h prepartum, raised
tail head, anorexia,
Bitch Vomition, drop in 1-20 rectal temp 24 h
prepartum, nesting behavior.
Mare Drop in mammary secretion electrolytes
Waxing of teats
16. Theories of parturition initiation
Physical factors 1. Increase in fetal size: this increases uterine
irritability
2. Uterine distension : reversal of progesterone block
3. Fatty degeneration of placenta and presence of
infarcts:
leads to interference in fetal nutrition
Biochemical factors:
1. Increase in CO2 tension in maternal blood due to
increased fetal activity: this ↑uterine contractility
2. Release of fetal antigens:→serotonin →release of
collagenase and stoppage of
blood supply to cotyledons.
17. Neuroendocrine factors: FETAL factors
1. ↑ in cortisol in adrenals→convert P4 to E2 &
release of PG
2. ↑ in ACTH by pituitary →stimulate cortisol
release
3. ↑ in CRH in hypothalamus →stimulate ACTH
4. ↑ in endogenous opiods →stimulate ACTH
18. MATERNAL factors
1. Reversal of P4 block → ↑ myometrial contactility
2. Release of relaxin → dilation of the birth canal
3. Placental estrogen rise →release of PG ↑ myometrial
contactility
4. Pro-inflamatory cytokines → dilation of the birth canal
5. Release of PG → softening of cervix, contractions ↑
6. Release of Oxytocin → ↑ myometrial contactions
19. Stage 1 (Initiation of Parturition)Stage 1 (Initiation of Parturition)
Fetal StressFetal Stress
Due increase in size and limited space
Fetal
Adrenal Gland
Fetal
Adrenal Gland
Corticoids (cortisol)Corticoids (cortisol)Corticoids (cortisol)Corticoids (cortisol)
Release of pituitary ACTH
(adreno-corticotropic hormone)
Release of pituitary ACTH
(adreno-corticotropic hormone)
1) Removal of progesterone block
2) Elevation of repro. tract secretion
1) Removal of progesterone block
2) Elevation of repro. tract secretion
Removal of Progesterone BlockRemoval of Progesterone Block
How does progesterone secretion is inhibited?
Elevated cortisol promotes the synthesis of 3 enzymes
These 3 enzymes convert progesterone to estradiol
Elevated cortisol promotes the synthesis of 3 enzymes
These 3 enzymes convert progesterone to estradiol
17 hydoxylase17 hydoxylase 17-20 lyase17-20 lyase AromataseAromatase
20. Fetal hypothalamus
↓
Fetal Pituitary
↓
ACTH
↓
Fetal adrenal
↓
Adrenal corticosteroids
↓
Convert progesterone to estrogen ← Feto placental estrogens → Relaxin
↓
↓ → →→ → →→→ → →→↓ Cervical softening ← ← ← ←
↓
Cotyledons / Myometrium ↑
Proinflamatory cytokines
↓
Luteolysis ← Release of PGF →oxytocin ↓
↓ ↓
↓
Decrease in serum progesterone ↓
↓→ ↓ ↑ Abdominal contractions
Myometrial contractions → Fetal Expulsion
↑
Oxytocin
↑
Posterior Pituitary
Possible endocrine changes that occur during the
periparturient period in the sow, ewe, cow and their effects
23. Final Role of Oxytocin
Sensory Neurons in Cervix
Oxytocin from
Posterior Pituitary
Myometrial
Contractions
24. Orientation of Fetus
• Fetus must reorient prior to parturition
– Initially on back
– Reorient so feet and head will exit first
– Breech
• Rear of fetus comes first
• Orientation not important in pig
• Abnormal orientation results in dystocia
27. Placenta
Liver
Left Atrium Lungs Right Atrium
Foramen
Ovale
Ductus
Venosus
Ductus
ArteriosusAorta
Umbilical Arteries
Umbilical Vein
Portal Vein
Vena Cava
Head
and
Heart Tissues
Fetal Circulatory
System
28. Liver
Left Atrium Lungs Right Atrium
Foramen
Ovale
Ductus
ArteriosusAorta
Portal Vein
Vena Cava
Head
and
Heart Tissues
Adult
Circulatory
System
Ductus
Venosus
29. Perinatal Fetal Changes
• Immune status
– Has no antibodies to protect
– Gets passive immunity from mother
• Gut permeable to antibodies in colostrum
• Only first 1 - 2 days
• Rabbit, rat, man get some antibodies absorbed
through placenta
30. Prepartum fetal changes:
Changes do occur in the fetus before delivery and these are essential because the
fetus has to prepare itself for the external environment outside the uterus. The
changes include
Maturation of fetal lungs: The surfactants in the lungs increase which reduce the
surface tension within the alveoli.
Increased output of tri-iodothyronine and catecholamines to meet the increased
metabolic demands
Closure of the ductus arteriosus and the closure of the foramen ovale
Increased glycogen reserves in the liver to meet the demands
on delivery by the production of glucose as a source of energy
post delivery.
31.
32. Stages of Labor
• Preparative (2 to 12 hours) 1st stage
– Myometrial contractions
– Uterine pressure
– Abdominal discomfort
– Cervical dilation
– Appearance and rupture of first water bag
(Chorio-allantois)
33. Stages of Labor
• Expulsion of fetus (30 to 180 min) (2nd stage)
– Strong uterine contractions
– Rupture of the allantochorion
– Appearance of the fetus wrapped in amnion
– Maternal recumbence and straining
– Not only uterine but abdominal contractions as well
– Rupture of the amnion and fetal delivery
34. Stages of Labor (cont.)
• Expulsion of the placenta (1 to 12 hours) and uterine
involution (3rd stage)
– Uterine contractions
– Chorionic villi loosen
– Expulsion of the placenta
– Delayed in ruminants due to presence of cotyledons separating
independently
– Suckling induces oxytocin release which triggers
further uterine contractions
35. Species First stage of labor Second stage Third stage (Placental
expulsion)
Cow 4-24 h (Bluish
vascular
semitransparent
chorio-allantois
appears & ruptures
0.5 – 3 h (Amnion appears with
the fetus. Fetus is delivered)
12-16 h (Placenta is
expelled)
Buffalo 1-12 h 45-90 min 7-12 h
Mare 1-12 h 30 min Within 3 h
Ewe/Do
e
6-12 h 0.5-1 h Within 3-6 h
Sow 12-24 h 0.5-4 h After 2-3 piglets or 4 h
post farrowing
Bitch 4-24 h 1st puppy within 2 h of 2nd stage
of labor. 5-60 min between
puppies. Total time upto 24 h
After each puppy or
within 2 h of last puppy
Cat 2-12 h 1st kitten within 5-60 min of
labor. Subsequent kittens every
5-60 min
Within 2 h of last kitten
Camel 3-48 h 5-80 min Within 4 h
Duration of different stages of labor in domestic animals
39. Stages of labor in a goat
1
2
3
1. The first water bag(allantochorion) is protruded
2. The second water bag (amnion) and the fetus are
protruding through the vulvar lips.
3. The placenta is being dropped in the third stage of labor
