Dystocia: fetal

• Abnormal parturition/prolonged gestation (more than 65 days).
• Cause:
  • Fetal oversize or deformity, eg hydrocephalus, conjoined twins.
  • Abnormal fetal presentation, position or posture.
  • Single kitten pregnancy.
• Signs: abnormal parturition/gestation, strong contraction for >1 hour without birth of kitten.
• Diagnosis: history, clinical signs, vaginal digital examination, ultrasonography, radiography, vaginoscopy.
• Treatment: dependent on cause of dystocia; most likely will result in a Caesarean section.
• Prognosis: good for future fertility; guarded for neonatal survival.

• Abnormal parturition Parturition/gestation Pregnancy-gestation.
• Noticeable abdominal contractions for >1 hour without the birth of a kitten.
• Strong contractions for 2-3 hours after the birth of a kitten.

• Presence of milk (not always a presenting sign on primparous queens).

• Initial examination, radiology and ultrasound plus possible Caesarean section and after-care.

• Inaccuracies in calculating gestation period may cause delivery of premature kittens (but this is much less likely than in bitches as copulation tends to be more closely associated with ovulation in the cat).
• Usual anesthetic risks for neonates after Caesarean section Cesarean section.

• Fetal oversize (genetic predispostion/single kitten).
• Fetal deformity.
• Fetal malpresentation/position/posture.
• Fetal death.
• Insufficient fetal fluids.
• Inadequate fetal ACTH stimulus  →  failure to initiate parturition (single kitten pregnancy).

General

• Fetal size.

• Litter size.
• Breed (incidence of dystocia more common in brachycephalic breeds than in dolichocephalic breeds).
• Stress.

• Physiology of feline parturition Parturition has not been well researched, but is likely similar to other mammals.
• Dystocia may be due to single kitten syndrome, abnormal presentation/position/posture or fetal oversize/deformity. 
• Single kitten pregnancy  →  primary uterine atony  →  failure to initiate parturition.
• Posterior presentation is normal in felids - as in other polytocous animals.
• Fetal malposture (eg shoulder flexion or even breech posture) may not prevent birth in many queens.
• Fetal oversize/malposture/malposition  →  impacted birth canal  →  myometrial fatigue  →  secondary uterine atony.

• 3-4 hours after the onset of parturition in cases of secondary uterine inertia brought on by fetal dystocia.

• Prolonged gestation (failure of parturition at full term).
• Prolonged labor.
• Radiographic evidence of single kitten.
• Presentation of a part of a deformed or excessively large kitten at the vulva.

• Failure of parturition to begin or to progress normally.

Queen

• Abdominal straining every few minutes.
• Some queens cry out in pain during straining.
• Milk can be expressed from the mammary glands.
• Licking of vulvar lips/abnormal discharge.
• Intermittent, weak or no straining if secondary uterine inertia.

Digital examination per vagina

• To determine if fetus in birth canal.

Abdominal palpation

• Kitten detected.

Radiography

• See abdominal radiography Radiography: abdomen.
• To determine number of kittens present and their location, eg single kitten in abdomen   or several kittens with one in pelvic inlet.
• If accurate time of breeding unknown, visible fetal teeth are a good indication of term pregnancy.
  Inaccurate indicator of fetal viability - unless gas accumulation is visible = fetal death.

Ultrasonography

• To determine viability of fetuses     .
• Heart rate of fetus should be >250.
  Severe fetal bradycardia (<200 bpm) is best indicator of distress.

Vaginoscopy

• An otoscope can be used to evaluate inside of vagina for presence of fetal obstruction.

Kitten

• Meconial staining of the skin and/or meconium inhalation due to fetal distress.

Queen

• Presence of unborn kitten in birth canal.

• Meconium inhalation.

• Maternal dystocia  Dystocia: maternal.

Causes of abdominal discomfort

• Abdominal discomfort unrelated to the reproductive tract.

• Dependent on cause/type of dystocia.

Obstructive

• Gentle manipulation if reducible malposture or malposition.
  Ensure adequate lubrication.
• Caesarean section if relative or absolute fetal oversize/deformity or non-reducible malpresentation/posture/position Cesarean section.

Elective Caesarean section

• If single kitten pregnancy and parturition has not begun by 65 days after the first breeding (even if queen does not have milk) Cesarean section.

• Good for future fertility; guarded for neonatal survivability.

Refereed papers

• Recent references from PubMed and VetMedResource.
• Holst B S, Axnér E, Öhlund M et al (2017) Dystocia in the cat evaluated using an insurance database. J Feline Med Surg 19 (1), 42-47 PubMed.
• Smith F O (2012) Guide to emergency interception during parturition in the dog and cat. Vet Clin North Am Small Anim Pract 42 (3), 489-499 PubMed.
• Pretzer S D (2008) Medical management of canine and feline dystocia. Theriogenology 70 (3), 332-336 PubMed.
• Traas A M (2008) Surgical management of canine and feline dystocia. Theriogenology 70 (3), 337-342 PubMed.