Dystocia : Causes, Treatment and Prevention ผศ. ชัยวัฒน์ จรัสแสง

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.

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

The stages of birth First stage Second stage Third 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

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

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

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

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

Fetal terminology Presentation Position Posture 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.

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

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 %

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

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

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

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

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

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

Vink Jack

HK calf puller

Vaginal examination Examination of the fetus Evidence of fetal life Evidence of fetal death

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

Treatments Mutation and force extraction Caesarian section Fetotomy

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

Hock flexion

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

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