CAL - Parturition in LA

Question 1

What is Parturition?

Answer 1

• Parturition is the process of delivering the young of a species and its placenta from the uterus of its dam.
• A number of events, which vary between species, need to occur in sequence for the successful initiation of parturition.
• Although the physiology behind this process can be explained and the endocrine changes are well documented, the factors which initiate birth and therefore terminate pregnancy after a specific gestation length are still not fully understood.

Question 2

Which large animal species reaches sexual maturity earliest?

Goat, Sheep or Pig

Answer 2

The age of sexual maturity ranges from:

• 4-8 months in goats
• 6-8 months in pigs
• 6-15 months in sheep

GOAT

Question 3

Which large animal species reaches sexual maturity last?

Alpaca, Cow or Horse

Answer 3

Alpaca

The age of sexual maturity ranges from:

• 7-18 months in cows
• 12-24 months in horses
• 14-24 months in alpacas

Question 4

gestation length:

Alpaca, Cow, Goat, Horse, Pig and Sheep

Answer 4

• Alpaca → 343 days
• Cow → 280 days
• Goat → 150 days
• Horse → 330 days
• Pig → 114 days
• Sheep → 145 days

Question 5

First Stage of Parturition: Preparatory Stage

Answer 5

• Positioning of the foetus for birth - The normal position of a foetus is with the front feet pointing out the cervix, right-side up with the chin resting on forelegs. With cattle, sheep and horses, any other position is considered an abnormal position and may result in dystocia.
• Dilation of cervix
• Exposure of foetal membranes through the vulva with possible rupture

Question 6

Second Stage of Parturition: Expulsion Stage

Answer 6

• Uterine contractions intensify, leading to
• Abdominal pressing by the dam, followed by
• Expulsion of the foetus

Question 7

Third Stage of Parturition: “Cleaning” Stage

Answer 7

During this stage, the placental membranes (afterbirth) are expelled

Question 8

Signs of Impending Parturition

COW/EWE/DOE

Answer 8

• Slackening of pelvic ligaments
• Change in mammary secretion from transparent secretion to colostrums
• Fall in temperature of 0.6°C around 54 hours before birth (Ewbank 1963)
• Signs of abdominal pain
• Occasional straining
• Irregular rumination
• ‘lowing’ and kicking at the belly
• May stand with back arched and tail raised
• May go down and rise again frequently

Question 9

Signs of Impending Parturition

SOW

Answer 9

• Most farrow at night
• Swelling of vulva 4 days prior
• Mammary growth 1-2 days prior
• Milk expressed 24 hours prior
• Sows in late pregnancy tend to mostly be asleep in lateral recumbency
• Within 24 hours of birth of the first piglet there is a marked restlessness and nest-making activity
• Intensely active period is followed by recumbency and rest
• Intermittent clawing and champing of the bedding
• Periods of activity and rest alternate
• In the hour preceding the birth of the first piglet the sow will settle into lateral recumbancy

Question 10

Signs of Impending Parturition

HEMBRA (alpaca)

Answer 10

• Majority of normal birthings occur during daylight (usually 6am to 2pm)
• Udder development
• Relaxation of pelvic ligaments
• Female often separates herself from herd
• Stand up and lie down frequently
• Legs may be put out to the side
• May urinate frequently

Question 11

Signs of Stage 2

COW/EWE/DOE

Answer 11

• Straining more frequent
• Animal often remains standing initially
• Typically lays down during passage of head through vulva
• Remains recumbent until calf/lamb/kid is born

Question 12

Signs of Stage 2

SOW

Answer 12

• Cannot distinguish 2nd and 3rd stage labour in sow; placentas of adjacent piglets are often fused and may be expelled between piglets
• Usually remain recumbent; can stand, or change sides after initial births
• Intermittent straining with leg paddling movements
• Before each birth a small amount of foetal fluid will be passed together with tail twitching
• The most parturient effort is made to expel the first piglet

Question 13

Signs of Stage 2

HEMBRA

Answer 13

• Female usually remains standing; can lay down and get up frequently
• If recumbent will usually stand when head and legs have passed through vulva
• Female may have short rests once the head and forelimbs are passed

Question 14

Signs of Stage 3

ALL SPECIES

Answer 14

• Expulsion of placentae

Question 15

Sexual Maturity, Gestation Length, # of offspring, placenta type, 1st 2nd and 3rd stage length and term for parturition

Answer 15

Question 16

What should be included in an “on farm partuition box” for owners

Answer 16

It is advisable for Farmers/Owners to have the following equipment to hand for assisting in parturition if necessary.

• Clean bucket
• Warm water
• Antibacterial solution (eg. Hibiscrub)
• Obstetric lube/Sterile KY jelly
• Calving/Lambing ropes/chains
• Calving Jack (for cattle only, ensure Farmer knows how to use correctly.

If Farmers/Owners are inexperienced they should not be encouraged to intervene unless they have spoken with their Vet.

Question 17

Incidence of Dystocia in FA

Answer 17

• Mare 1-2% ponies, to 10% in draught breeds
• Cow 3-4% dairy cows, higher beef breeds
• Ewe 2-3%
• Doe 1-2%
• Sow < 1%

There are many causes of dystocia in animals. These can be related to the mother or the foetus.

Question 18

Maternal Causes of Dystocia

Answer 18

Question 19

Fetal Causes of Dystocia

Answer 19

Question 20

How do we classify foetal disposition?

Presentation

Answer 20

The relationship between the longitudinal axis of the foetus and that of the dam and the portion of the foetus entering birth canal.

• longitudinal (normal) anterior
• or longitudinal posterior
• or transverse

Question 21

How do we classify foetal disposition?

Position

Answer 21

The relationship between the dorsal surface of the foetus (vertebral column) and the surface of the maternal birth canal to which it is applied

• dorsal (normal)
• ventral
• lateral

Question 22

How do we classify foetal disposition?

Posture

Answer 22

The disposition of the movable appendages of the foetus

• limb flexions
• neck flexions
• head displacements

Question 23

Answer 23

• Presentation: [Longitudinal anterior (normal)]
• Position: [Dorsal (normal)]
• Posture: [Lateral neck flexion]

Question 24

Answer 24

Presentation: [Longitudinal anterior (normal)]

Position: [Dorsal (normal)]

Posture: [Bilateral hip flexion]

Question 25

Answer 25

Presentation: [Transverse]

Position: [Lateral]

Posture: [Bilateral carpus flexion]

Question 26

Answer 26

Presentation: [Longitudinal posterior (normal)]

Position: [Dorsal (normal)]

Posture: [Bilateral hip flexion]

Question 27

Answer 27

Presentation: [Longitudinal anterior (normal)]

Position: [Dorsal (normal)]

Posture: [Bilateral carpus flexion]

Question 28

Why do fetal Dispositions Occur?

Answer 28

There are several reasons why foetal disposition may occur. These include;

• weak / uncoordinated uterine contractions
• delayed development of foetal reflexes
• weak / uncoordinated foetal movements
• competition for uterine space
• ankylosis of joints

Question 29

Ankylosis

Answer 29

abnormal stiffening and immobility of a joint due to fusion of the bones.

Question 30

Identifying Dystocia

Answer 30

• In the majority of cases the first step is to identify the position of the calf, or any physical reasons for dystocia ie. Ringwomb.
• The next step is often to use local anaesthesia in the form of an epidural to stop the dam straining and thereby permit manipulation per vaginum. The instilling of extra lubrication in and around the calf/lamb/kid etc will often aid correction of malpresentations.

Other steps that may be required include;

Traction (manual or with calving jack)

Episiotomy

Fetotomy

Caesarean

Euthanasia of dam

Question 31

Dystocia and Calves

Answer 31

• Dystocia is a well recognised risk factor for mortality and morbidity in calves.
• The instance of neonatal death from normal births is more likely secondary to prematurity, dysmaturity, congenital defects and infectious processes.

Question 32

A-B-C of CPR

Answer 32

• Airway
• Breathing
• Circulation

The key areas for successful resuscitation are;

• Establishing a patent airway
• Initiating breathing
• Establishing adequate circulation

In cattle, resuscitation post dystocia focuses on establishing breathing and correction of acid-base abnormalities. Generally, cardiac resuscitation is not attempted as claves born without a heartbeat are unlikely to be viable.

Other important areas to consider are maintaining body temperature and ensuring adequate colostrum is received.

Question 33

Clearing of Airway in Neonate

Answer 33

• Immediately after delivery the calf should be placed in sternal recumbancy to maximize ventilation and minimize ventilation-perfusion imbalances. To ensure a patent airway the calf should have their nose and mouth cleared of any fluid or physical obstruction.
• Suspension of calves by the back legs to clear the upper respiratory tract should only be for a short period of time (~<90 seconds). Care must be taken if the calf is swung by the back legs to clear the airway and this can cause injuries to both the calf and worker.

Question 34

Stimulation and Respiration in the Neonate

Answer 34

• Calves should make active respiratory movements within 30 seconds of being delivered.
• Primary apnoea is defined as the absence of spontaneous breathing for 1 to 5 minutes. It is therefore important to stimulate respiration in newborn calves. When hypoventilation or apnoea is present assistance is generally indicated

Question 35

Mechanical Stimulation of Respiration in Newborn Calves

Answer 35

There are many methods that have been advocated for establishing respiration and airway patency in calves.

• Rubbing calves with bedding or towels is an attempt to stimulate the phrenic nerve.
• Placing a finger, piece of straw, or other implement in the nose initiates a gasping reflex and helps aerate the lungs.
• The use of acupuncture points on the muzzle has been advocated.
• Pouring cold water over the calf’s head or ear has been recommended for hypothermic respiratory stimulation.
• Positive pressure ventilation has also been advocated in calves. This is primarily used to initiate respiration as opposed specifically to treat hypoxia.
• Mouth-to-nose or mouth-to-mouth resuscitation is commonly initiated when presented with a calf that is not breathing
• Care must be taken as air often travels down the oesophagus filling the abomasum, further impeding the calf’s ability to breathe. Placing digital pressure over the oesophagus may help divert the air to the trachea during this process. Mouth-to-mouth and mouth-to-nose procedures are also less ideal because of the potential of contracting zoonotic diseases.
• A cuffed endotracheal tube can be used to provide positive pressure ventilation. A 5.5- to 9.5-mm tube is appropriate for use in calves and can be easily passed with the use of a long-bladed laryngoscope. When the calf becomes strong enough to fight it, the endotracheal tube should be removed.

Question 36

Pharmacological Stimulation for respiration in Neonatal Calves

Answer 36

• Doxapram hydrochloride stimulates peripheral chemoreceptors and medullary respiratory centres of the brain. The drug has a wide margin of safety and has been used successfully to stimulate respiration.
• Doxapram may also have some benefit in stimulating respiration in calves that have respiratory depression caused by drugs, particularly from xylazine given to the dam during calving. Doxapram is unlikely to have a positive effect in calves with profound central nervous system depression secondary to hypercapnia. These animals are likely to require ventilatory support.
• Secondary apnoea is defined as the absence of spontaneous breaths 5 minutes or more after delivery. This situation offers a grave prognosis and doxapram is ineffective in these calves.

Question 37

Cardiac Stimulation of Neonates

Answer 37

• In general, cardiac resuscitation is not undertaken in animals born without a heartbeat. Successful resuscitation is unlikely in these settings.
• In foals, the likelihood for revival is approximately 50% if cardiac resuscitation is begun before development of a non-perfusing rhythm.
• Survival of less than 10% is expected when resuscitation efforts begin after asystole. (cardiac arrest rhythm with no discernible electrical activity on the EKG monitor)
• In calves that are profoundly bradycardic, epinephrine (0.2 mL/kg of 1:10,000 solution IM or 0.1 mL/kg of 1:10,000 solution IV or intracardiac) can be administered.
• This produces a rapid tachycardia; however, the calf is still likely to require intubation and its ventilation assisted

Question 38

Colostrum and the Neonatal Calf

Answer 38

• Calves require colostrums to provide passive immunity to disease that they may be exposed to early in life. Colostrum contains high levels of the immunoglobulin IgG. Adequate passive immunity is achieved when calf blood IgG levels are equal to, or greater than 10g/L at 24 hours after birth.
• Absorption of immunoglobulins must occur before the calfs intestines become impermeable to the large Ig proteins (gut closure). This process tends to have occurred by 24 hours.
• It is important to establish a suitable protocol for calf colostrum management. It is recommended that to ensure adequate Ig intake it is important to administer two feedings of colostrum (2 L each) containing at least 50 g Ig/L. Ideally feed 2 L at birth and another 2 L 12 hours later. If adequate stores of colostrum are available then a further 2L could be fed before the 24 hours passes.
• Fresh or frozen (thoroughly defrosted and warmed before use) is the best colostrum to use. Any recently calved cow should be milked of her colostrum; typically 8L is possible. The farmer can then use 6 of these litres for the protocol above, and then freeze 2 litres for use in another calf. It is important to note that the amount and quality of colostrum in heifers will be reduced. In these circumstances a store of colostrums from older cows can be incredibly useful.

Question 39

Post-Partum Complications

Answer 39

The incidence of post partum complications is increased post dystocia. This is particularly true when farmer or vet intervention has occurred. Potential complications include;

• Hypocalcaemia
• Hypomagnasaemia
• Hypophosphataemia
• Combinations of the above
• Post parturient paralysis
• Metritis
• Endometritis
• Uterine tears
• Vulval tears
• Uterine prolapses
• Mastitis
• Retained foetal membranes
• Peritonitis
• Complications post surgery (caesarean)