Bitches and queens should be encouraged to deliver in a familiar area where they will not be disturbed. Unfamiliar surroundings or strangers may impede delivery, interfere with milk letdown, or adversely affect maternal instincts. This is especially true in young or primiparous animals. The dam’s apprehension or nervousness may subside in a few hours, but in the meantime, the neonates must receive colostrum and be kept warm; nursing should be closely supervised. Mini-dose oxytocin (diluted to 10 U/mL, 0.25 U/queen or 1 U/bitch, SC, every 4–8 hours, as needed) can reduce maternal stress. Oxytocin nasal sprays may improve maternal instincts.
A nervous dam may ignore the neonates or give them excess attention. She may lick and bite at the umbilical stump, causing hemorrhage or damage to the abdominal wall that may lead to evisceration. Excess grooming of the neonate may prevent it from nursing.
If the dam’s maternal instincts fail, she may assume sternal recumbency and not allow nursing, or she may leave the neonates unattended. It is not unusual for the dam to pick up the pups and to rearrange them in the box, especially after delivery of each pup; however, she should then assume the normal nursing position.
The principal metabolic disease associated with pregnancy is puerperal hypocalcemia. It is rare in queens and most common in bitches weighing < 20 kg, and it is exacerbated by improper perinatal nutrition (excessive calcium/phosphorus supplementation or an unbalanced prenatal diet).
Common inflammatory diseases in the postpartum period include metritis and mastitis, which can occur together due to hematogenous spread of bacteria (usually Escherichia coli).
Retention of a placenta or its remnants does not commonly cause metritis; retained placentas are usually expelled spontaneously. Dystocia could lead to metritis. Clinical signs include continued straining as if in labor, the presence of a fusiform mass associated with the uterus (best identified by ultrasonographic evaluation), abnormal vulvar discharge, fever, and lethargy as the infection develops.
If administered within 24 hours after the onset of labor, oxytocin may improve uterine tone and facilitate passage of retained placenta(s); if oxytocin is ineffective, or if it is > 24 hours postpartum, prostaglandin F2alpha (dinoprost; 0.1 mg/kg, SC, every 12–24 hours) or cloprostenol (1–3 mcg/kg, SC, every 12–24 hours to effect) can usually induce passage of the placenta. Metritis is a potentially serious condition requiring appropriate supportive care and (nursling-safe) antimicrobials; however, it has a good prognosis and can usually be managed on an outpatient basis, permitting continued maternal care of neonates. Retained placentas do not always cause problems.
Mastitis is more common in bitches than queens. The bacteria associated with mastitis tend to be coliforms or Staphylococcus spp. Galactostasis can predispose bitches to mastitis, as can excessive human manipulation of the mammary glands. Mammary glands should be observed to ensure that all are being nursed.
Mastitis and metritis can coexist via hematogenous spread. Supportive care, appropriate (nursling-safe) antimicrobials, and physical therapy (warm compresses, evacuation of purulent milk, cool cabbage leaf compresses) are indicated to treat mastitis. Mastitis is potentially serious and can be associated with sepsis.
Major postpartum uterine hemorrhage is rare unless uterine trauma has occurred. Oxytocin (< 24 hours postpartum) and prostaglandins can be administered if the uterus is healthy; hysterectomy must be performed if hemorrhage is unabated and substantial (ie, causing blood loss anemia). Screening for an underlying coagulopathy and appropriate therapy should be undertaken.
Uterine subinvolution results in hemorrhagic spotting for > 12–16 weeks (the normal period of involution in bitches). Treatment is unnecessary unless blood loss is substantial (suggesting a coagulopathy) because the condition usually resolves spontaneously. Future fertility is unaffected.
Agalactia (other than that caused by severe illness) is uncommon in bitches and queens. Determination that lactation is adequate should be performed before elective cesarean section. If an emergency cesarean section is required, regardless of the status of lactation, intervention is indicated (see below). Female dogs and cats with inadequate lactation at term should be thoroughly evaluated for metabolic or inflammatory disorders (metritis, eclampsia, mastitis), nutritional deficits, dehydration, or periparturient pain and treated appropriately.
Evaluation of a CBC, serum chemistries, vaginal discharge, and uterine ultrasonography may be required. The normal presence of colostrum (typically not copious) should not be confused with agalactia. The level of neonatal contentment and daily weight gain (after the first 24 hours) indicates adequate lactation. Milk letdown is promoted by oxytocin release, a reflex triggered by nursing; therefore, neonates must spend adequate time suckling.
Disruption of the pituitary-ovarian-mammary gland axis can result in idiopathic agalactia. Agalactia can be associated with premature delivery of neonates. Iatrogenic agalactia can result from progesterone supplementation during gestation, which is not advised.
Because estrogen promotes lactogenesis, the adequacy of mammary development should be assessed before removal of the ovaries if ovariohysterectomy is elected at a cesarean section. Ovariohysterectomy or hysterectomy at cesarean section in general practice is associated with higher morbidity and mortality rates secondary to hemorrhage, prolongs anesthesia time, and is a more invasive procedure for the dam. Nursing of offspring is also delayed.
Inadequate lactation can be stimulated if treatment is prompt. Mini-dose oxytocin (0.25–2 U, SC, every 2 hours) should be administered.
Neonates should be removed from the dam before each injection and returned 10 minutes later. Neonates should be supplemented adequately, but not excessively, to ensure survival but not prevent them from suckling vigorously. Mammary glands should be gently hand stripped if suckling is not vigorous.
Concurrent administration of metoclopramide (0.1–0.2 mg/kg, SC, 3–4 times every 24 hours) to the dam promotes prolactin release.
Acepromazine at mild tranquilization dosages may also facilitate milk letdown.
Therapy should continue until lactation is adequate, usually 12–24 hours later.
