Labor and Delivery in Dogs & Cats

• Behavioral Changes:

    ◦ Changes in disposition and behavior.

    ◦ Becomes reclusive, restless, and nests intermittently.

    ◦ Often refuses to eat and may sometimes vomit.

    ◦ Panting and trembling may be seen.

• Vaginal Discharge: Normal discharge is clear and watery.

B. Stage II Labor (Neonate Delivery)

• Characteristics: Marked by visible abdominal efforts accompanied by myometrial contractions.

• Delivery Interval:

    ◦ Efforts should not typically last more than 1–2 hours between puppies or kittens.

    ◦ Normal labor is associated with shorter intervals (30–60 minutes) between neonates.

• Total Delivery Time: Can range from 1 to >24 hours.

• Signs: Anorexia, panting, and trembling are common. Female continues to nest between deliveries and may nurse and groom neonates intermittently.

• Vaginal Discharge: Can be clear, serous to hemorrhagic, or green (uteroverdin).

C. Stage III Labor (Placenta Delivery)

• Definition: The delivery of the placenta.

• Completion: Female dogs and cats vacillate between stages II and III until delivery is complete.

• Outcome: All fetuses and placentae are delivered vaginally, though not always delivered together.

Dystocia (Abnormal Labor):

A. Causes of Dystocia

• Maternal Factors: Uterine inertia or pelvic canal anomalies.

    ◦ Most common cause clinically: Secondary inertia, which develops after the delivery of one or more neonates.

• Fetal Factors: Oversize, malposition, malposture, or anomalies.

• Combination of Factors.

B. Diagnosis of Dystocia

• Objective Diagnosis:

    ◦ Uterine contractility is inappropriate (generally infrequent, weak myometrial contractions) for the stage of labor.

    ◦ Excessive fetal stress results from labor.

    ◦ Primary Inertia: Requires tocodynamometry for diagnosis.

• Subjective Diagnosis (When to Suspect Dystocia):

    ◦ Stage I labor is not initiated at term.

    ◦ Stage I labor lasts >24 hours without progressing to Stage II.

    ◦ Stage II labor does not result in a vaginal delivery within 1–2 hours.

    ◦ Stage II labor does not result in the completion of deliveries in a timely manner (within 4–12 hours).

    ◦ Excessive fetal or maternal stress.

    ◦ Moribund or stillborn neonates are seen.

C. Management and Treatment

• Monitoring: Uterine and fetal monitors are used to detect and track labor and fetal viability.

• Medical Management (Used only if inertia is detected and Stage II is anticipated, and after 8–12 hours of established Stage I contraction patterns; premature use is suboptimal):

    ◦ Calcium Gluconate (10% solution):

        ▪ Action: Increases the strength of myometrial contractions.

        ▪ Indication: Given when uterine contractions are ineffective or weak.

        ▪ Administration: 1 mL/22 kg body weight, given 2–4 times daily. Given SC (no more than 6 mL/site) to avoid potential cardiac irritability associated with IV administration.

    ◦ Oxytocin:

        ▪ Action: Increases the frequency of uterine contractions.

        ▪ Indication: Given when uterine contractions are less frequent than expected.

        ▪ Dosage: 0.5–2 U in dogs; 0.25–1 U in cats.

        ▪ Caution: High doses saturate receptor sites and make the drug ineffective.

• Surgical Intervention (Cesarean Section): Indicated for:

    ◦ Unresponsive uterine inertia.

    ◦ Obstructive dystocia.

    ◦ Aberrant uterine contractions.

    ◦ Progressive fetal distress (e.g., persistent or worsening bradycardia) without response to medical management.