Dystocia Flashcards
what is the most common cause of dystocia in cows
feto-maternal disporportion
what is the most common cause of dystocia in sheep
malpresentations
List 5 effects of dystocia
reduced welfare
reduced production
stillbirth
dam death
post partum problems increased
what are the 4 options for management of dystocia
Manual correction and deliver per vaginum
Caesarean section
Foetotomy (foetus needs to be dead)
Euthanasia of dam +/- foetus
List 4 indications of caesarean section
foeto-maternal disproportion
malpresentations that cannot be corrected
breech calves
elective (e.g. high value calves)
when is a c-section not suitable - what should you do instead in this case
if calf is decomposing
perform a foetotomy
when is a foetotomy suitable
Foetus will not survive – only suitable if already dead (preferable to C-sec if not fresh) or if euthanasia of foetus required
what is a partial foetotomy
removal of part of the foetus only (e.g. head)
what is a total foetotmy
division of the whole foetus into 2 or more sections
List 5 advantages of a foetotomy
can be quick
reduction in foetal size allows easier delivery
can be done without assistance
avoids C-section
can be performed minimal equipment if required
List 3 disadvantges of a foetotomy
risk of iatrogenic injury
can take a long time (especially total)
requires training and technical competency
subcutaneous foetotomy
limb removal without skin
what are dropsical conditions
excess accumulation of amniotic fluid in amniotic cavity that is associated with a genetic or congenitally defective fetus.
List 4 indications of a percutaneous foetotomy
Foeto-maternal disproportion
Pathological foetal oversize
Congenital foetal malformations
Malpresentations that cannot be corrected
Describe Hydrallantois
Excess fluid accumulation in the allantois
placental origin
fetus is normal
Describe Hydramnion
excess fluid accumulation in the amnion
fetal origin
fetal abnormalities present
what occurs in hydrallantois
Up to 10x expected volume of allantoic fluid
Fluid accumulates after mid-gestation
reduced number of placentomes
permanent changes to endometrium
what is the prognosis with hydrallantois
guarded to poor
if survives cull of cow recommended- as subsequent fertility is affected
List 6 clinical signs of hydrallantois
bilateral abdominal distention
uncomfortable
inappetant
reduced/absent rumen function
recumbency
tight uterine wall palpable per rectum
What occurs in Hydramnion
fetal abnormalities
Progressive abdominal enlargement in 3rd trimester
Slower development than hydrallantois
Uterus and abdomen accommodates extra fluid better
Less sick cow
may go undiagnosed until parturition
describe how to treat dropsical conditions in cows
induce/ terminate pregnancy - need to provide replacement fluids to cow
euthanasia
trochar and drain fluid
Describe Arthrogryposis
Relatively common malformation
Limb ankylosis
can be seem with Schmallenberg
List 3 possible causes of arthrogryposis
genetic- Charolais
viral infection in utero- schmallenberg, bluetongue, Akabane
Teratogenic plants- Lupines- not in UK yet
What is Schistosomus reflexus
congenital abnormality
‘inside out’ fetuses
RARE
what do you need to be careful not to confuse Schistosomus reflexus with
uterine rupture of cow
this requires uterine exam
What is Congenital chondrodysplasia
congenital abnormality
Bulldog calves
does not always cause dystocia
List 3 breeds associated with Congenital chondrodysplasia
dexters
holsteins
jerseys
describe Hydrocephalus
Increase in CSF volume domed head
Calves born alive may have neuro deficits
what can cause hydrocephalus
Teratogenic viruses implicated= BVDv, BTV, Akabane virus (not UK)
May also form part of mixed congenital disorders
what is Large offspring syndrome
congenital abnormality
‘ abnormal offspring syndrome’
may be 2x averge size
what is large offspring syndrome associated with
embryo transfer
in vitro techniques
cloning
what is ancephaly
no head
what is otocephaly
some head structures present but no skull
what is bicephaly
2 heads
what is a Teratogen
agents causing fetal abnormalities or death
timing of exposure influences the outcome
if zygote exposed to teratogen what happens
affected by chromosomal or genetic abnormalities. Often result in embryonic death
if embryo exposed to teratogen what happens
affected by environmental and infectious agents. Most high risk period for developing abnormalities
if fetus is exposed to teratogen what happens
more resistant to environmental teratogens but structures that develop late are still susceptible to being affected (e.g. palate)
List 5 common viral teratogens
BVD virus
Border disease virus
Schmallenberg virus
Bluetongue virus
Akabane and aino viruses
List 4 examples of environmental teratogens
hemlock
nitrates/ nitrities
ergotism - mouldy feed
lead
List 5 examples of pharmacological teratogens
benzimidazoles- sheep
tetracyclines- all ruminants
steroids- all ruminants - abortion
prostaglandins- all ruminants - abortion
xylazine- all ruminantes
at what point in gestation can PGF2a be used to terminate pregnancy
<100 days- 90% chance
101-150 days- 60%
>150- <40%
>270- will induce parturition
how can giving glucocorticoids be used to terminate pregnancy
reduces placental secretion of progesterone= pregnancy loss
>270 days- induces parturition
if terminating mid-late pregnancy what drugs do you use
dexamethasone and prostaglandin