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Newborn Squirrel Monkey SOPs

This SOP describes procedures and measurements to be performed on newborn squirrel monkeys during the first day of life. Many of these procedures are designed to identify life-threatening conditions in these animals. These procedures will also provide important information for this critical period in the squirrel monkey's life. This SOP also establishes a standard approach to management of squirrel monkey infants to prevent rejection and respond in the event that they are rejected by the dam.

These procedures may be postponed or canceled at the discretion of the clinical veterinarian if they represent a potential risk to infant health and/or bonding with the dam.

Live Birth

  1. Find the next ID number in the Birth Log Book and fill in the date and dam's ID number.
  2. Complete the Basic Animal Information form on each new infant.
  3. Collect the placenta from the cage if it is available:

    Weigh the placenta and place it in a plastic bag; record the weight of the placenta on the Basic Animal Information (Birth Record Form).

    Indicate the dam's ID# on the bag and place the bag into the refrigerator located in the PRL main animal hallway.
  4. Check with the supervisor for instructions on when to proceed with the work-up.
  5. The following procedures should be performed while wearing cotton gloves:

    Palpate the dam to insure that the placenta has passed.

    Palpate the dam's nipples to insure that she is lactating.

    Determine the sex of the infant.

    Weigh the infant; report a body weight of less than 90 grams to the supervisor. (This is the only time the infant should be separated from the dam.)

    Examine the infant for signs of trauma or other possible clinical problems; report any such signs to the veterinarian.

    Perform a rapid glucose test using the Chemstrips BG; report any glucose less than 40 mg/dl to the supervisor.

    Mark the infant by shaving a portion of the infants body.
  6. Place the dam and infant into the maternity pen/cage (if in use).
  7. Record exam results, infant body weight, marking and glucose on the Birth Log book summary sheet and make any comments or notes about the delivery, dam or infant on the Birth Information Narrative Sheet.

Stillbirth or Abortion

  1. Find the next ID number in the Birth Log Book and fill in the date and dam's ID number.
  2. Collect the fetus or infant's body and placenta from the cage or dam.
  3. Weigh the body; note whether it is a whole body or a portion.
  4. Place the body in a plastic bag, labeled with the fetus/infant's ID number and dam ID number.
  5. Weigh the placenta and place it in a plastic bag.
  6. Place both the placenta and fetus/infant in the refrigerator.
  7. Record the weight of the fetus/infant and placenta on the Basic Animal Information (Birth Record) form.
  8. Complete the information on the Birth Log Book summary sheet and make any notes or comments on the Birth Information Narrative Sheet.
  9. Complete a necropsy submission form--be sure to include the fetus/infant's and dam's ID number.
  10. Notify the supervisor and follow instructions as to whom else to notify.

Maternal Rejection

The following procedures give the highest priority to keeping the infant with the dam, or fostering the infant onto another colony female. The reasons for this high priority are:

  • Maternal rearing permits normal behavioral development
  • Maternal rearing greatly increases technician time available to care for other animals
  • Infants that are maternally reared do not have to meet nursery entry criteria listed below; even "poor doer" infants can be maintained and allowed time to recover if they can be raised on the mother or foster mother

Each situation in which an infant is rejected is different and may require changes in procedures. Changes in procedure will be made only by consulting the clinical veterinarian and Dr. Williams unless the life or health of an animal is immediately threatened.

Prevention of Infant Rejection

The following are factors that may lead to infant rejection by the dam, along with suggested strategies for preventing rejection:

  • Illness or injury in the dam or the infant

    Prevent illness or injury through good husbandry (for example, maternity cages with bedding to prevent head injuries).

  • Primiparous dam (first-time mother): Insure that juvenile females are housed with older females having infants to permit learning of appropriate maternal behavior

  • Kidnapping or harassment by cage-mates

    Use maternity pens and cull or temporarily single-house animals who habitually harass mother-infant pairs.

  • Human intervention with the dam or the infant (either during delivery or post-partum)

    Minimize handling of mothers and infants during the first week after birth. When clinical and research procedures are required, complete preparations should be made before catching the mother-infant pair, the procedure should be done as quickly as possible, and the pair rapidly released to their enclosure. In order to avoid imparting a foreign smell to the infant, cotton gloves are to be worn over rubber gloves for all handling of rejected infants.

  • Mother with history of rejecting her offspring

    Pregnant animals with this history should be identified prior to delivery. If clinical problems or research requires that these animal be restrained during the first week post-partum, the clinical veterinarian or investigator should be contacted, informed of the mother's history of rejecting infants, and a decision made regarding the need to catch the pair for the procedure.

Returning Infant to the Dam After Rejection

Prior to attempting return of the infant to the dam, the infant should be evaluated and treated as required using the "Weak or Comatose Animal" instructions located in the red notebook in the clinic.

Once the clinical veterinarian has declared the infant fit for a return attempt, it is the responsibility of the supervisor to oversee the return. In order to avoid imparting a foreign smell to the infant, cotton gloves are to be worn over rubber gloves when handling rejected infants. The mother should be checked for:

  • Passage of placenta
  • Lactation

The first attempt to return the infant to the dam should be performed in a maternity pen bedded with wood shavings or a single-animal cage to reduce the chance of infant injury in the event of a fall.

  • Place infant on the awake dam and the place the pair in the cage or pen

  • Observe the pair from a distance for the first 15 minutes. Note and record any unusual reactions or activities by the dam or infant. Notify the supervisor of any problems

  • Observe the pair at frequent intervals for the rest of the day. Note and record any unusual reactions or activities by the dam or infant. Notify the supervisor of any problems

Human activity in the animal room or section of runs where the return is taking place should be minimized to avoid frightening the dam.

Some pulling at the infant, sniffing and licking of the infant's face by the mother should be expected. This must be distinguished from biting or other abuse. The return attempt should be terminated if:

  • The infant is unable to properly hold on to the mother
  • The mother is actually abusing the infant

If the infant is weak, medical treatment or a brief period in the nursery to allow feeding and stabilization of body temperature may be required by the clinical veterinarian, followed by a first or second attempt to return the infant to the dam.

If return to the awake dam fails, the procedure can be repeated with the dam lightly sedated with 10-30 mg of ketamine (0.1-0.3 cc) SC. The infant should be rubbed over the dam to absorb the dam's scent--particularly the dam's anogenital region. This type of return should always be done in a single-animal cage.

Fostering Procedures

Because of the limited number of fostering attempts that are possible with a single infant, careful selection of foster mother candidates is important. During the delivery season, foster mother candidates should be "nominated" on a regular basis by technicians and supervisors. A list of potential foster-mother ID numbers is to be kept in the clinic where they can be readily accessed. Criteria for foster mothers include:

  • Recent loss of an infant (dams who have had recent stillbirths or late-term abortions should also be considered)

  • Willingness to accept a foster infant based on past history or observed behavior (for example, protecting the infant or attempting to pick it up)

  • Foster mothers should be of the same species as the infant they are fostering (general rule)

An inability to lactate does not exclude a female from being a foster mother; it is less desirable, however, since it requires that the infant be nutritionally supplemented by humans for an extended period.

Fostering procedures are similar to those for returning an infant to the dam in that the first attempt to return the infant to a foster mother should be performed in a maternity pen bedded with wood shavings or a single-animal cage to reduce the chance of infant injury in the event of a fall.

  • Place the infant on the awake foster mother and place the pair in the cage or pen

  • Observe the pair from a distance for the first 15 minutes. Note and record any unusual reactions or activities by the dam or infant. Notify the supervisor of any problems

  • Observe the pair at frequent intervals for the remainder of the day. Note and record any unusual reactions or activities by the dam or infant. Notify the supervisor of any problems

Human activity in the animal room or section of runs where the return is taking place should be minimized to avoid frightening the foster mother.

Some pulling at the infant, sniffing and licking of the infant's face by the foster mother should be expected. This must be distinguished from biting or other abuse. The return attempt should be terminated if:

  • The infant is unable to properly hold on to the foster mother
  • The mother is actually abusing the infant

If the infant is weak, medical treatment or a brief period in the nursery to allow feeding and stabilization of body temperature may be required by the clinical veterinarian, followed by a first or second attempt to return the infant to the foster mother.

If the return to the awake foster mother fails, the procedure can be repeated with the foster mother lightly sedated with 10-30 mg of ketamine (0.1-0.3 cc) SC. The infant should be rubbed over the foster mother to absorb the foster mother's scent--particularly the foster mother's ano-genital region. This type of return should always be done in a single-animal cage.

Placing Infants in the Nursery

Placement in the nursery will be considered only as a method of last resort to insure survival of infants considered to have a good chance of normal development. The decision to admit an infant to the nursery will be made by the clinical veterinarian. Criteria to be considered nursery placement include:

  • Body weight of 80 grams
  • The absence of serious illness (in the judgment of the clinical veterinarian)

Nursery Housing

Newborn infants admitted to the nursery are to be placed into a nursery cage. A hot water-heated blanket is used in the nursery cage to simulate the mother's warmth. A pump containing a heating element forces warm water (not to exceed 33°C) through the blanket which is placed under the nursery cage. For sanitary reasons, a thin, plastic-lined absorbent pad is placed on top of the heating blanket.

When the infant is placed into the cage, it is to be offered a surrogate. This surrogate is made from a cylindrical shaped piece of terry cloth or similar material. Usually, the infant will cling to the surrogate when it is offered.

Nursery infants are to be observed frequently (at least hourly) throughout the day for signs of distress. Any abnormalities must be reported to the supervisor and the clinical veterinarian immediately.

The decision to release an infant from the nursery will be made by the supervisor, in consultation with the clinical veterinarian.

Nursery Procedures and Feeding Schedules

A temperature and weight is to be taken on each animal in the nursery each morning. Record this temperature and weight on the animal's individual Infant Feeding and Weight Chart (in the 'Wt' column for that day).

The nursery feeding schedules will begin at 7:00 a.m. and may run up to 12:00 midnight. Infants will be fed at 30- to 60-minute intervals, depending upon the condition of the infant and the amount of food it consumes.

SMA, an iron-fortified milk formula, is fed to the infants using a 1-ml syringe with a short (1/2") length of tubing attached to the hub. This tubing is usually cut from a length of tubing attached to a 'butterfly' infusion set.

When attempting to feed an infant, the infant should be grasped gently (while still clinging to the surrogate) and, with the syringe held in an upright position, the milk formula should be slowly introduced into the infant's mouth. (You should see a natural suckling reaction when the tubing touches the infant's mouth.) Continue to introduce the formula slowly until the infant stops taking the formula. Do not attempt to force more formula into the animal than it will normally consume.

Record the amount consumed in the appropriate 'Feed' column on the infant's individual Infant Feeding and Weight Chart. Report any problems with feeding infants to the supervisor immediately.

After each feeding, completely flush out the syringe and tubing with water until all formula has been rinsed from the syringe and tubing. When not in use, each syringe and tubing "nipple" must be kept in Nolvasan disinfecting solution. Do not use Instracal or any other disinfecting solution for this purpose.

As the infant matures, the amount of formula taken will increase. In accordance with the supervisor's instructions, the frequency, volume and nature of feedings may change. The infant may then 'graduate' to a small feeding bottle fitted with a rubber nipple. At the discretion of the supervisor or veterinarian, solid monkey chow and fruits may be placed into the cage of larger infants.


© 2014 The University of Texas MD Anderson Cancer Center