Dystocia : Causes, Treatment and Prevention

1. Dystocia : Causes, Treatment and Prevention ผศ. ชัยวัฒน์ จรัสแสง

2. References • Arthur’s Veterinary Reproduction and Obstetrics : Noakes, D.E., Parkinson, T.J. and England, G.C.W. 8 th edition (2001) • Handbook of Veterinary Obstetrics : Jankson, P.G.G. 2 th (2004) • The technique of Fetotomy in Large Animals : Bierschwat, C.J. and deBois, C.H.W.

3. Dystocia : consequences and cost of dystocia • Increased stillbirth rate mortality • Increased neonatal morbidity • Increased mortality rate for the dam • Reduced productivity of the dam • Reduced subsequent fertility and increased chance of sterility • Increased likelihood of puerperal disease in the dam • Increased likelihood of culling

4. The stages of birth • First stage • Relaxation and dilation of cervix • Fetus adopts birth posture • Uterine contraction • Chorioallantois enters vagina • Second stage • Uterine contraction continues • Fetal enters birth canal • Abdominal contraction • Amnion enters vagina • Fetus expelled • Third stage • Placenta expelled

8. Causes of dystocia • Maternal causes • Failure of explosive forces • Uterine • Abdominal • Obstruction of birth canal • Bony pelvis • Soft tissue • Fetal causes

9. Uterine failure of explosive forces • Uterine • Primary uterine inertia • Myometrial defects • Biochemical deficiencies • Hysteria/environmental disturbance • Oligoamnion • Premature birth • Secondary uterine inertia • Uterine damage or rupture • Uterine torsion • Abdominal

10. Obstruction of the birth canal • Bony pelvis • Fracture, breed, diet, immaturity, neoplasm, diseases • Soft tissue • Vulva : congenital, fibrosis, immaturity • Vagina : congenial, fibrosis, prolapsed, neoplasia, abscess, hymen • Cervix : congenital, fibrosis, failure to dilate • Uterus : torsion, deviation, herniation

11. Fetal causes • Hormone deficiencies • ACTH/ cortisal • Fetopelvic disproportion • Fetal oversize • Fetal monster • Fetal maldisposition • Malpresentation • Malposition • Malposture • Fetal death

12. Fetal terminology • Presentation • The relationship between the long axis of the fetal and the long axis of the birth canal. (anterior, posterior, transverse, vertical) • Position • Surface of the maternal birth canal to which the fetal vertebral column. (dorsal, ventral, lateral) • Posture • The position of the head and limbs of the fetus.

15. Dystocia in the cow • Incidence 3-10 % • Environmental factors • Diet, supervision, disease, Induction of birth • Intrinsic factor • Age, parity, body weight, pelvic size • Breed • Calf weight, sex and size • Gestation length • Sire effect • Calf presentation

16. Causes of dystocia in the cow • Fetopelvic disproportion 45 % • Fetal malpresentation 26 % • Failure of cervix and vagina to dilate 9% • Uterine inertia 5 % • Uterine torsion 3 % • Maternal abnormalities 7 % • Fetal abnormalities 5 %

17. Failure of the explosive forces • Uterine inertia • Premature birth • Failure of abdominal expulsive forces • Uterine rupture • Uterine torsion

18. Obstruction of the birth canal • The bony pelvis • The soft tissues • Torsion of the uterus • Downward deviation of the uterus

19. Fetopelvic disproportion • Fetal monster • Conjoined twins • Dicephalus • Siamnese twins • Shistosomus reflexus • Bulldog calf • Perosomus elumbis • Hydropcephalus • Fetal anasarca • Fetal ascites

22. Fetal maldisposition • Malpresentaion • Posterior presentation • Transverse presentation • Vertical presentation • Malposition • Ventral position, lateral position

25. Fetal maldisposition • Malposture • Lateral deviation of the head • Downward deviation of the head • Retention of a forelimb • Carpal flexion • Shoulder flexion • Retention of hindlimb • Hock flexion • Hip flexion

26. Approach to a case of dystocia in the cow • Assistance required • Restraint of the patient • Sedation • Uterine relaxation • Epidural anesthsia • Equipment • Case history • General clinical examination

31. Vink Jack

32. HK calf puller

33. Vaginal examination • Examination of the fetus • Evidence of fetal life • Evidence of fetal death

34. Manipulative delivery • Is vaginal delivery likely to be possible and successful? • Comparison of the size of the fetus and birth canal

35. Treatments • Mutation and force extraction • Caesarian section • Fetotomy

36. Mutation and force extraction • Retropulsion • Rotation  longitudinal axis • Version  transverse axis • Extension and Adjustment of the extremities • Traction

40. Hock flexion

41. Mutation and force extraction • Repulsion of the proximal portion of the extremity • Lateral rotation of the huddle portion of the extremity • Traction on the distal portion of the extremity

42. Forced Extraction • Retraction from out-site • Mutation already • Caution • Disposition • Oversize • Small birth canal • Uterine inertia • Cervix no dilate • Paralysis obturator nerve • Severe vulva tear