Foetal Dystocia & Perinatal Mortality Flashcards
foetal dystocia is commonly caused by…
- foeto-maternal disproportion
- foetal maldisposition
- congenital abnormalities & teratogens
- foetal death
foeto-maternal disproportion is most common in…
cattle
foeto-maternal disproportion is rare in
horses & pigs
foeto-maternal disproportion is caused by (calf relative to dam)
- increased mass
- inappropriate conformation
- pelvic canal being too small/incorrectly shaped
calf birth weight depends on…
- breed
- parity of dam
- sex
- seasonal & climatic factors
- nutrition of dam
- length of gestation
- IVF/IVM embryos
When parents are of different sizes in cattle and bred, what does that mean?
offspring weight is near the mean weight of both appropriate pure-bred calves
if the dam is of a larger breed in cattle than the bull (2 different breeds mated) then that means
the dam exerts an influence towards her own weight
Which cattle breeds are known to have muscular dystrophy?
Belgian blues, some Charolais
What is the number 1 indication for C- section in cattle?
Recessive gene causing muscular hypertrophy
birth weights of what sex are larger in cattle, irrespective of breed?
male calves
Which sex of calves have longer gestations?
males
increased birth weight is associated w/ and increase in
dystocias
the mean spring weight of calves born after a warmer than normal winter are…
4.5 kg lighter
in dairy breeds the calf size and conformation decline in…
autumn & early winter
cold weather means there is a increase in
uterine blood flow thus providing an increase in nutrient supply to the foetus
energy expenditure is always directed towards…
the offspring
When is calf birth weight influenced the most based on the dam?
severe nutritional deficiency of the dam
What happens during pregnancy if the dam is undernourished?
- placentome of ruminants changes to compensate for nutrition
- energy is sequestered to the growth of the foetus
At what point in pregnancy will severe nutritional restrictions reduce calf birth weight?
the last 90 days of gestation
restricted energy intake has greater influence than
protein (cattle)
There is a reduction in birth weight due to a reduction in
foetal muscle mass
severe reductions in foetal birth weight due to manipulating the maternal diet may
place neonate in jeopardy
gestation length of cattle is associated w/
birth weight & breed
male calves w/ longer gestation periods have a higher incidence of…
dystocia
What abnormalities are associated with prolonged gestations & dystocias?
- developmental abnormalities
- hypophyseal & adrenal-cortex hypoplasia
birth weight of calves due to IVF/IVM may be …
greater than those from AI/natural mating
why is birth weight of calves done by IVF/IVM larger?
constituents of media in which the sperm is kept
IVF/IVM leads to increased incidences of…
- hydrops allantois
- congenital heart conditions
- etc.
most common type of bovine dystocia
Foeto-maternal disproportion in anterior presentation
anterior presentations of foeto-maternal disproportion in cows & heifers may be due to
delays in intervention leading to emphysematous decomposition
What are methods of assessing an oversized foetus?
- sire, gestation length
- Hindson’s Index
- Trial traction
What is the Hindson’s index?
width of feet vs the pelvis diameter tells you how much progress you can get
What is the general ratio that tells you delivery will be difficult according to Hindson’s index
if the inter-ischial distance to digital diameter ratio is less than 2.25, then the delivery will be difficult
What is the treatment for dystocia due to foeto-maternal disproportion?
- normal expulsive forces supplemented by traction
- diameter of the vulval opening increased by episiotomy
- Caesarean
- Volume of foetus reduced by foetotomy (dead calf)
In ewes, common cause of dystocia is due to
bulky body features from the ram
how to remove a dystocia in a ewe that is alive?
traction on limbs or head (anterior presentation) w/ snares & lubricant
how to remove a dystocia in a ewe that is dead?
foetotomy
foeto-maternal disproportion in anterior presentation is relatively uncommon in…
mares
