Parturition and FoalNeonatal Care

LACP pg. 163

Average 335-340 days.

Variable- breed, season, sex of foal, plane of nutrition, fetal genotype

Gestation Length

Equine Gestation HormonesProgesterone/Progestogens

Progesterone initially rises, followed by a slight ↓ then ↑ to a peak at d 80, then gradually ↓ to 1-2 ng/ml during mid-late gestation (d 150). 

Second ↑ associated with formation of accessory & secondary CL.  Late gestation progesterone rises (last month of pregnancy)

Once embryo enters uterus, it migrates throughout the uterine body and both horns until 16-17d (becomes to big to pass through horn.

This migrations signals the dam that she is pregnant. (contacts endometrial surface repeatedly) FIXATION

Embryo – 40d Fetus – after 40d

60d-7 months- fetus develops slowly

(fetal organ development) 8 months- increase in size to about 60% of its

weight in the last 3 months.

Placenta

Placenta takes over progesterone production ~d 100 until foaling.

Complete placental formation is done at 150 days.

DAY 150 - Firm placental attachment

Placenta Attachment of placenta to endometrium begins

around day 40 of gestation and not complete until 120d.

Endometrial cups (day 25) fetal in orgin, form from girdle cells, and invade the dam’s endometrium . Forms horseshoe like ring of white cups. Produce ECG that stimulates CL to produce progesterone. Cups degenerate at day 70.

Loss after day 40- no return to heat for 3-4 months.

Epitheliochorial and noninvasive (materanal and fetal epithelium contact)

Attachement- diffuse in that the membranes are attached to all portions of the uterus with the exception of the cervix- no attachement

Chorioallantois- outer fetal membrane, chorionic side attaches to dam- red and velvety, allantoic side- fetal side bluish grey in color.

Amnion is thin, white membrane covers the fetus

Impending BirthVaccinate & Deworm 30 day prior

Most Obvious Hypertrophy mammary

glands obvious from 8th month Maiden may display little until

just before foaling Distention of the teats

4-6 d pre-foaling Waxing of the teats

1-72 hrs pre-foaling An increase in milk Ca

1-3 d pre-foaling

Fescue Toxicity

Pull mare off fescue at least 1 month before foaling.

(endophyte-infected)

Calcium concentration rise sharply as the time of foaling approaches

Foaling Facilities Stall-

14x14 for light mares

Disinfect between foaling

Good air circulation

Safe, solid construction

Straw bedding Paddock-

“clean” grassy paddock

Safe, good fencing

Other horses?

Impending Birth

More Subtle Signs Softening and flattening of

the muscles in the croup Vulva becomes relaxed &

elongated. Maximal hours before parturition

Visible changes in the position of the foal

Vulva – thick & puffy with edema and may elongate

Pear shaped abdomen

Stages of Parturition

Stage 1 Onset: initial uterine contractions End: rupture of chorioallantois

(water bag “water breaks”) 2-4 hr Mare may stand up, pacing, lie

down, roll, pace, look or bite at flanks, sweat, frequent urination

Foal is being pushed toward the cervix

Stages of Parturition Stage 2

Onset: rupture of chorioallantois (8-20L)

End: delivery of fetus- cord is broken

Timeline 20-30 min Contractions occur in groups

of 3-4 followed by a rest period of 3 to 5 minutes

Forefeet visable, soles pointing down

Oxytocin release, uterine contractions reinforced

When the chest is through the vulva the foal can breathe on its own. May go in & remove the amniotic sac.

Not breathing – rub foal, take straw and put in nose, breath into nose

Ensure a clear airway by clearing membranes and fluids from the nostrils

Foaling EmergenciesMay Need Assistance Red mass evident at vulva (placenta

seperation) Strong straining & no feet evident at

vulva within 5 min Heavy straining with feet in vulva

but no further progress in 10 min One foot missing No progress for more than 15 min

after first water breaks Rectovaginal perforation occurs Mare foals while standing

“Red Bag”

Foaling EmergenciesMay Need Assistance

If the chorioallantois does not break and the velvety-red surface of the chorioallantois is presented at the vulva, it should be immediately ruptured because this indicates that the placenta is separating from the endometrium and that fetal oxygenation will be impaired

- cut placenta and pull foal (fescue toxicity)

Stages of Parturition Stage 3

End: passage of the fetal membranes Expel placenta 30minuets -4 hrs post-

foaling If no passed within 4-6 hours, the placenta

is considered to be retained– metritis, necrotic uterine wall, septicemia, laminitis

Can tie placenta in knot above hocks

•Examine Placenta

http://video.google.com/videosearch?q=horse+breeding&hl=en&emb=0&aq=f#q=foaling&hl=en&emb=0

•Arrange the membranes in a capital "F" position, with the pregnant horn uppermost and the body forming the vertical bar of the "F"•Tip of the nonpregnant horn is the most likely part of the placenta to be retained•Placenta Examination

•Weight •Length of umbilical cord & location•Appearance of gross lesions, missing pieces

Placenta Examination

Retained Placenta: Treatment After 2 hrs Oxytocin Infusion of fluid into allantoic cavity Antibiotics Non-sterioidal anti-inflammatory drugs Frog support pads Deeply bedded stall

Abortions

No common, greater in mares over 14yrs Twins- 90% abort, Abortion in mid to later gestation may occur

in single horse, or many “abortion storm” (viral or bacterial)

If this happens fetus should be placed on ice and examined by vet within 12 hours.

Abortion time Control

EHV 6+ mo Vaccine

EV arteritis 6+ mo Vaccine

Lepto 5+ mo Isolation

Mare Repro. Loss Syndrome

45-120d10+ mo

Eastern Tent caterpillars

Placentitis 5-9 mo Caslick

Umbilical torsion Anytime None

Twins 5+ mo None

Stress Anytime Decrease stress

Endotoxemia Anytime Determine cause and avoid

Postpartum Mare & Foal CareUmbilical Cord Care Allow foal to break fetal membranes. Never cut the cord. Spray or dip umbilical cord stump with antiseptic

solution 3-4X per day for 3-4 days

Ascending placentitis Premature seperation

Umbilical cord is made of

Umbilical vein, 2 umbilical arteries, and urachus

Vein becomes the falciform ligament

Arteries become the round ligaments of the bladder

Best to let the cord rupture naturally

Neonatal Care

The neonatal period is the period following birth, which most clinicians consider the first 4 to 5 days

This period is one of susceptibility to many diseases and conditions that can be threatening to the immediate and long-term health of the foal

Good neonatal care is a combination of sound management practices and recognition of normal and abnormal conditions

Foal FactsFoal Facts

Newborn foal should exhibit a suckle reflex at 20 minutes after birth, stand within 30-60 min.and nurse within 60 to 180 min.

The first urination occurs within 10 hours and the meconium should be passed by 24 hours after parturition. (Meconium is the first fecal material that the newborn foal normally evacuates. It appears in pelleted form, brown to black in coloration. They must pass this or become impacted.)

LACP pg. 165

Colostrum First milk secreted by a mare coming into

lactation (poor lactation can be supplemented with domperidone)

Production During last 2-4 weeks of gestation Under hormonal influencesImportance Transfer of passive immunity to the suckling

foal (“Liquid Gold”) Specificity of protection achieved by vaccinating pregnant mares 30-60 days before parturition

Produced only once – beware of leakage! Provides energy to foal Encourages passage of meconium

Colostrum

Quality Relates directly to antibody content Good quality:

≥ 50 (70) g/L IgG and specific gravity > 1.060 Thick, sticky, yellow secretion All foals should have IgG measured between 8-24 hours

Colostrum Evaluating Colostrum QualityWhen? Assess before foal sucklesHow? Physical appearance

Thick, sticky, yellow secretion indicates good quality Dilute, white or translucent secretion indicates poor quality

Stall Side Tests

Banking of Colostrum

Only good quality colostrum

Storage at - 20ºC:

IgG concentration stable for 12 months

Other immune components (complement, etc) and nutritional

components decrease significantly

Storage at -70ºC:

Permanent maintenance of all components

Colostrum

Evaluating Colostrum Quality

ARS Refractometer

Designed for measurement of sugar

concentration of

solutions (BRIX type)

1-2 drops of colostrum needed

Results in less than 1 minute

http://www.arssales.com/equine/html/refractometer.html

Colostrum

ARS Refractometer - Results

Evaluating Colostrum Quality

Foal Immune Status

Evaluation of serum IgG status

When? Typically at 12-24 h after birth

Peak serum levels of IgG achieved by 18h Absorption of immunoglobulins from small intestine essentially

complete If failure of passive transfer: treat with IV plasma

Can measure early at 6-12 h IgG first detected in foal’s serum at 6 h of age If no IgG or very low level at 6-12 h: can give colostrum to

increase levels

Foal Immune Status

Evaluation of serum IgG statusSnap Foal IgG Test ELISA Use whole blood, serum, or plasma Calibrator spots indicate IgG

levels of 400 and 800 mg/dl Sample color is proportional to

IgG content Results in 10-15 min. Expensive but convenient

Foal Aftercare: within 1st 24 hours

Give enema to prevent Meconium impaction

Give Tetanus antitoxin Check for presence of suckle reflex Check for any malformations or

deformities Take blood sample from foal. Perform a physical

Neglected foals

Milk can be expressed from the mammary gland by use of an inverted 60-ml dosing syringe to apply suction

Common Foal Diseases

Sepsis Perinatal Asphyxia Prematurity Neonatal Diarrhea Respiratory Disease

Sepsis

Common in foals Fever, elevated heart rate, or respiratory rate

Causes: improper umbilical care, failure of passive transfer, poor sanitation, maternal illness such as placentitis

Treatment: intensive nursing care, immunoglobulin therapy, antimicrobial treatment

Perinatal Asphyxia

Lack of oxygen “dummy foal syndrome” cerebral edema and

ischemia and necrosis of the brain

48 hours after birth foal my lose the affinity for the mare, become unable to suckle, wander aimlessly, and potential for seizures.

Prognosis is good if there are no seizures

Prematurity

Equal to or less then 320 days

Low birth wt, weakness, short hair coat, increased joint motion, rear limb flexural laxity, take longer to stand, suckle reflex may lack vigor, domed forehead, floppy ears

Survival depends on degree of complication

Diarrhea Common Frequency of diarrhea, suckling of foal,

weather other foals are affected

Cause: Foal heat diarrhea, rotavirus, coronavirus, septicemia, salmonella, clostridium, Strondyloides westeri, lactose intolerance.

Iv fluid therapy, probiotics, analgesics, plasma

Respiratory Disease Can be hard to diagnose: restlessness and

agitation, increased respiratory rate or distress.

Diagnosis- thoracic radiograph, arterial blood gas, pulse ox, ultrasound

Cough is rarely seen, nasal discharge uncommon, respiratory rate and rhythm can be unreliable, mucous membrane won’t reflect mild to moderate pulmonary disease, Thoracic auscultation can be misleading

Bacterial pneumonia Viral pneumonia Fungal pneumonia Milk aspiration Acute respiratory distress syndrome Persistent pulmonary hypertension Fractured rib Pneumothorax Pleural effusion

Examination of the inner ear reveals petechiation

The critically ill neonatal foal should be placed on a warm, well-padded surface in semisternal recumbency

The jugular groove is widely clipped and prepared with sterile solutions before intravenous catheter placement

Proper restraint of the foal is achieved by gently cradling one hand under the neck and grasping the base of the tail with the other hand.

Limb Deformities

Angular- Varus, Valgus, Windswept Axial- off set knees Rotational- muscular Spiral- toed in Flexor – week or contracted flexors

Most are congenital, premature, dietary, blunt trauma to the growth plate, uneven hoof balance

Angular

Valgus

Varus

Windswept

Treatment

Stall rest X-rays Medial extensions Self correction (valgus) Surgical correction Therapeutic trimming

Axial- off set knees

No treatment, undesirable in race horses, can lead to unsoundness

Rotational- toed out

Self correction Muscular development of thoracic muscles

Spiral – toed in

Fetlock is in normal

alignment

No treatment, corrective

shoeing masks problem

Flexor- contracted

Bone is longer then the surrounding tendons

treatment

Tetraclycine- shown to relax the muscle/tendon unit

Bandaging Passive extension stretching Air splints PVC splints surgery

Flexor- laxity

rest

Bone growth catches up with tendons Swimming Care for soft tissues if damaged