Dystocia Flashcards
what are the clinical history questions to ask with dystocia?
- Has the dam given birth before – if so where there complications and what where these?
- What has recently been observed in this dam?
- Has there been recent vulval discharge?
- Have uterine / abdominal contractions been noted and if so when?
- Please remember the difference between uterine and abdominal contractions
- Have any fetal membranes / fluid been expulsed?
- Have any fetuses been delivered?
- Any other relevant information (inguinal hernia etc)
what is the main cause of dystocia in bitches?
Almost ¾ of small animal dystocia cases are maternal and most common is primary uterine inertia (uterine contraction occur but then stop and puppy is not pushed into birth canal)
what is the length of pregnancy in the bitch?
- Remember length of normal pregnancy is 63 +/- 1 days from ovulation (but that the time of mating around ovulation is variable, therefore length of pregnancy is variable)
- The apparent length of pregnancy can vary from 58 to 72 days
what are the methods used to asses possible dystocia cases?
- Clinical history (mating 58 to 72 days before onset parturition)
- 63 days from ovulation
- So any methods that have been used to time ovulation?
- Decline in plasma progesterone (1.5 days before onset parturition)
- Decline in rectal temperature (due to the decline in progesterone) (24 hours before onset parturition)
- Onset of uterine contractions (2 to 4 hours before onset parturition)
- Onset of abdominal contractions (30 to 120 minutes before onset parturition)
what examinations can you do to investigate dystocia?
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Digital examination
- Is the vestibule / vagina dilated?
- What is the state of lubrication of the tract?
- Are any fetuses present, are they alive, what is their presentation, position and posture?
- Are any fetal membranes present, are they intact, are they detached?
- What is the relative size of the birth canal and the likelihood of fetuses being delivered?
- Are any lacerations present?
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Endoscopic examination
- Is the cervix open (cannot detect in bitch or queen without endoscopic examiantion)
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Ultrasonographic examination
- Are fetuses alive, what is their size?
- What is the fetal heart rate?
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Radiographic examination
- Number and size of fetuses
- Signs of fetal death: change in posture, overlapping skull bones, fetal/uterine gas
- Measure Progesterone
what is the normal foetal heart rate?
what foetal HR indicates hypoxia?
what foetal HR indicate poor survival?
what foetal HR indicate intervention needs to be taken?
- Normal fetal heart rate at term 170-230 bpm
- Or, at least four times maternal heart rate
- Transient increases with foetal movement
- Fetal heart rates less than 150 bpm
- Indicates stress (hypoxia)
- Fetal heart rates less than 130 bpm
- Poor survival if not delivered within 2 to 3 hours
- Fetal heart rates less than 100 bpm
- Immediate (medical or surgical) intervention to hasten delivery before demise of the pups
what are the physical and medical treatments for dystocia?
- Correction of foetal orientation
- Retropulsion, correct position / posture
- Traction
- Oxytocin administration
- After correction of obstruction
- Half life is short
- Oxytocin doses are often too high and cause tetany not coordinated contractions
- Oxytocin compresses placenta and worsens fetal hypoxia so is contraindicated if fetuses are bradycardia
- In large litters may be better option to go to Caesarean
- Calcium administration
- 2.5% solution (need to dilute 20% solution 1:7)
what percentage of manipulation/ medical treatment are successful vs how many end in caecarean?
Manipulation / medical treatment:
- Successful in 28% of bitches
- Successful in 30% of queens
Overall approximately 70% ultimately undergo caesarean
- 6% incidence of fetal death when presented within 5 hours of onset of second stage
- 14% incidence of fetal death when presented between 5 and 24 hours of onset of second stage
