Dystocia Flashcards
What initiates parturition?
Complex cascade of endocrine events
Caused by foetal stress (increased levels of ACTH –> foetal cortisol)
What are the 3 stages of parturition?
How long does this take?
Initiation of myometrial contractions (2-6 hrs)
Expulsion of foetus (30 mins)
Expulsion of foetal membranes (shortly after in SA, 1-6 hours in LA)
Dystocia is a difficult birth. What is a normal birth called?
Eutocia
What is the name of the species that only has one offspring?
Monotocous
With precocial offspring
What is the name of the species that has multiple offspring?
Polytocous
With altricial offspring
What stages of parturition cannot be distinguished in polytocous species?
2 and 3
What does more than offspring in a monotocous species result in?
Maldisposition
Smaller foetuses
Abortion (mares)
What is foetal disposition?
Spatial arrangement of foetus
In relation to pelvis of dam
And extremeties to self
Is foetal disposition more likely in monotocous or polytocous species?
Polytocous
What is the normal foetal disposition? What is abnormal (maldisposition?
Longitudinal dorsal anterior, with extension of limbs and neck
Abnormal = anything else
What should be described when stating foetal disposition?
Posture (disposition of head, neck, limbs)
Presentation (anterior/posterior)
Position (dorsal, ventral, lateral)
What are the consequences of dystocia?
Increased stillbirth rate Increased mortality of foetus and dam Reduced fertility Reduced productivity Increased risk of disease
Give examples of why dystocia might occur (foetal origin)
Foetal monsters Maldisposition Foeto-maternal disproportion Multiple births (monotocous) Both foetuses present simultaneously
Give examples of why dystocia might occur (maternal origin)
Expulsive forces insufficient Birth canal inadequate shape/size Prolapse Dislocation of scar-coccygeal joint Excess vaginal fat decreases diameter Uterine torsion Primary and secondary uterine inertia
What is primary uterine inertia? Is it more common in polytocous or monotonous species?
Deficiency in myometrial contractions prevents expulsion
Polytocous
