INDUCTION OF PARTURITION

Commonly performed in cattle, goats and mares to permit supervision of the birth; Cases need to be chosen carefully as the procedure can be fraught with complications. The primary complication being the birth of a premature or dysmature neonate. If immature at birth, the neonate will require intensive care, your time and the owner's money. Many die. Therefore, it is imperative that you perform the procedure at the correct time and explain the complications to the owner if you wish to keep your client and/or prevent litigation.

1. CATTLE
   
   1. Indications
      
      1. To avoid excessive calf size by earlier delivery (calves may gain 0.5 to 1.0 lbs per day during the final weeks of gestation.

      2. To increase the postpartum recovery period before the breeding season in late calvers (beef cattle in the USA: dairy cattle in New Zealand).

      3. medical reasons such as udder edema, hydrops allantois, vaginal prolapse, fractures.

   2. Disadvantages
      
      1. premature or dysmature calf if induced too early i.e. more than 2 weeks prematurely

      2. dam may not have adequate concentration of colostrum

      3. indicence of retained fetal membranes is high

   3. Drugs used-anticipate onset of labor 48 to 72h after injection
      
      1. glucocorticoids (dexamethasone 20 mg IM) MOST COMMON

      2. prostaglandins (PGF2a 25 mg IM)

      3. both DEX and PGF GOATS

   4. Indications
      1. As many goat owners hold regular jobs and they wish to be home when their does kid, inducing parturition gives them the opportunity to be present at kidding.

      2. induce parturition AFTER 144 to 146 days; does will kid at 30 to 33 h after injection if they have not been stressed; If stressed will kid between 48 and 72 hrs after tx; Stresses include moving the does to a new location within 2 weeks of kidding, separating does from their pen mates, illness, drastic changes in feed;

      3. No increase in the incidence of retained placenta

   5. Disadvantages
      1. Premature kids, poor viability if parturition is induced prior to 144 days

   6. Drug used
      1. PGF2a IM; Doses from 10 to 20 mg have been used successfully

2. HORSES
   1. Indications
      1. Need to have a veterinarian present for foaling because of previous injury (fractured pelvis), previous birth of a foal with NI, mare is ill, or is considered to be a high risk mare that may incur problems at foaling. Never to be performed for convenience!!!!

   2. Disadvantages
      1. Most common complication is the birth of a premature foal; second most common complication is premature separation of the placenta from the endometrium leading to a foal that experiences oxygen depravation during the birth process.

   3. Criteria
      1. Colostrum in udder UTMOST IMPORTANCE
         

         There is a relationship between fetal maturity and changes in the mammary secretion electrolyte concentrations of Calcium, potassium and sodium; To induce parturition and deliver a mature foal successfully must have the following:

(2) Mammary secretion K > Na

The sodium, potassium inversion usually occurs 48 to 72 hr before Ca rises to 40 mg/dl. Once Ca is 40 mg/dl, the mare will usually foal within 48 hr

There are various commercial kits available for measuring Ca in mammary secretions. Water Hardness Test Strips are an accurate and inexpensive method. No matter what method is used mammary secretions must be diluted and mixed; 1 part milk to 6 parts distilled water.

1. Second criteria- at least 330 days of gestation

1. Drugs
   1. Drugs of choice Oxytocin

(1) Multiple small IV injections 10-20 i.u. every 20 min

(2) Single IM bolus 100 i.u.

(3) IV boluses 20-40 i.u.

1. Fluprostenol (a synthetic prostaglandin) II.IMMEDIATE NEONATAL CARE

The health and management of the prepartum dam including nutrition, vaccination status, physical condition, and milk production (goats and cows) needs to be reviewed and programs implemented as needed.

1.A maternity area needs to be provided and closely supervised. The dams (including cows, ewes, does, sows, bitches, queens, and mares) need to be moved to the maternity area several days to at least 1 week prior to the anticipated time of delivery. Spacious, dry, well-bedded box stalls (cattle, mares), pens (goats, sheep), crates (sows) or whelping boxes (bitches, and queens though queens don't whelp!!!) need to be provided.

2.For large animals straw is the bedding of choice. For small animals shredded newspaper works fine.

3.Facilities need to be clean, dry, comfortable, free from drafts and excessive temperature fluctuations. Calves should be confined in well-lit, well ventilated, individual stalls, pens or hutches from birth until 60 to 12 weeks of age. Four to 8 foals of similar ages and their dams are usually housed together in paddocks. Depending on the weather, they may be brought in at night into box stalls. Sheep and goats are usually left out to run with the flock or herd. Sows are left in the crates with their litter as are puppies and kittens.

4.All neonates have limited fat reserves and quickly become hypoglycemic if left unattended without warmth or nutrition.

III. NEONATAL CARE WITHIN THE FIRST 24 HRS

A. Immediate Care

1.Establishment of an open airway; Normal respiration must be initiated within mins (< 5 mins) after the umbilical cord is severed. Pouring cold water over a calf, which elicits the sigh reflex, and rubbing the skin vigorously, both stimulate respiration. Various cardiac and respiratory stimulants are commercially available. Unfortunately they are frequently not within immediate reach.

2. Feed adequate quantities of colostrum (discussed below)
a.Adequate colostral immunoglobulin is the single most important factor in protecting a neonate from disease

3.Dipping the navel. For decades iodine was the disinfectant of choice for all neonates. One must be careful with foals, puppies, and kittens and not to allow too much of the iodine to come into contact with the skin as it is caustic (cut the iodine in half with water). However, recent work (1994) shows that iodine is not that successful in preventing bacterial inoculation of the umbilical stump when used in foals. It appears that clorohexadine may be the disinfectant of choice.

4.Physical examination of the neonate; this includes watching the animal's behavior. Abnormal behavior may be the first sign that something is wrong. There is no easy way to become familiar with normal behavior other than to OBSERVE, OBSERVE, OBSERVE; Check for congenital defects including cleft palate, atresia ani. Be familiar with what is the normal temperature, respiratory rate and heart rate of the neonate for each species that you work with. Some rough guidelines for calves, goats, sheep and foals:

Suckling reflex 1-20 mins
Time to stand 20-120 mins
Time to nurse 60-120 mins
Temperature 99-101šF
Heart rate 90-100 beat/min

B. Colostrum management

1.Adequate amount needs to be fed; For calves and foals at least 1 liter; for sheep and goats at least 0.5 L. Colostral IgG concentration must be high. Can be evaluated in large animals by measuring specific gravity of the colostrum (bovine and equine colostrometer available).

2.Evaluation of passive transfer of IgG in neonates

a.Definition of passive transfer varies with species; a safe rule of thumb is a serum IgG conc of at least 800 mg at 24 hrs of age.

b.There are various methods to measure serum IgG conc; the gold standard is radial immunodiffusion (SRID); Unfortunately it takes a minimum of 36 hrs to perform. If a neonate has inadequate serum levels it must be treated immediately. Rapid, accurate tests include: zinc sulfate turbidity, latex agglutination, ELISA's, glutaraldehyde.

1. Treat neonates with low serum IgG conc especially if the environment is not clean or the weather is cold and damp. Failure of passive transfer is the leading cause of septicemia. Septicemia is still the leading killer of neonates. Treatment before 18 hrs of age - colostrum orally; after 18 hrs plasma intravenously.

A.If orphaned or rejected neonates need to be fed at the minimum 4 times daily, kept warm and draft free. Placing hypothermic lambs in an oven set at 150-200šF has saved lives.

B.As mentioned above, calves are housed separately. Individual housing minimizes the spread of diseases and prevents calves from nursing each other. Calf separation also allows one to accurately assess feed intake and fecal consistency.