Dystocia Flashcards
What does dystocia mean?
- difficulty giving birth
What % of calvings are affected by dystocia?
8-10%
Causes of dystocia
At conception or early gestation
- foetal sex
- foetal abnormalities
- twins
- sire factors (e.g. breed, calving ease)
- dam factors (e.g. parity, calving history)
At late gestation
- gestation length
- foetal oversize
- dam undersize
- hypocalcaemia
- peri-parturient stress
At parturition
- foeti-maternal disproportion
- uterine torsion
- foetal malpresentation
- uterine inertia
- cervical or vulval stenosis
Most common causes of dystocia
Cattle = foeto-maternal disproportion
▪ 50-80%
Sheep = malpresentations
▪ > 50% of cases
Effects of dystocia
▪Reduced welfare
▪Reduced production
– Cow = subsequent lactation
– Calf = 1st lactation
▪ Stillbirth
▪Dam death
▪Postpartum problems ▪E.g. RFM, metritis, injuries
Options for management of dystocia
▪Manual correction and deliver per vaginum ▪Caesarean section
▪Foetotomy (foetus needs to be dead)
▪Euthanasia of dam +/- foetus
Manual correction and delivery
▪ Will only be successful if foeto-maternal disproportion NOT present
– Malpresentations
– Some soft tissue obstructions (e.g. vulval stenosis)
▪ Correct malpresentation
– Epidural can be helpful (if soft tissue obstructions)
– Consider episiotomy
Indications for c-section
▪ foeto-maternal disproportion
▪malpresentations that cannot be corrected
▪breech calves
▪elective (e.g. high value calves) (ethical q’s re breeding animals knowing they’ll need a c-section, e.g. Belgian blues)
When are c-sections not suitable?
- if calf decomposing→foetotomy
– would contaminate the dams abdomen with bacteria -> very likely to get peritonitis - Alternative approach needed if C-sec performed
Foetotomy (AKA ‘embryotomy’)
▪Foetus will not survive – only suitable if already dead (preferable to C-sec if not fresh) or if euthanasia of foetus required
– but euthanasia of the foetus is very tricky, esp without contamination/damage of the dam as well
▪Epidural recommended→provides analgesia and reduces straining
▪Partial or total
– Partial = removal of part of the foetus only (e.g. head)
– Total = division of the whole foetus into two or more sections
▪ Fetotome prevents soft tissue damage to the dam with the wire
Advantages of foetotomy
- Reduction in foetal size allows easier delivery
- Can be quick (especially partial)
- Can be done without assistance (although assistance recommended if possible)
- Avoids C-sec
– Especially useful if C-sec contraindicated
(emphysematous foetus)
– Better for dam in some circumstances - Can be performed with minimal equipment if required
– Especially sheep
– Partial and subcutaneous need less equipment
Disadvantages of foetotomy
- Risk of iatrogenic injury
– Can be severe or even life-threatening - Can take a long time (especially total)
– Exhaustion of dam and vet - Requires training and technical competency
Percutaneous foetotomy
- Percutaneous = dissection is made through foetal skin
- ‘classic’ technique
Subcutaneous foetotomy
= limb removal without skin
- An incision made in the skin
- Foetotomy knife introduced under the skin and limb dissected away from body
- Easier, less tiring and less equipment needed
Indications for percutaneous foetotomy
- Foeto-maternal disproportion
- Pathological foetal oversize
- Congenital foetal malformations
- Malpresentations that cannot be corrected
NB: these all only apply where the foetus is already dead
Indications for subcutaneous foetotomy
- Same as for percutaneous except correction must be achievable through limb removal only
Less common causes of dystocia
- Dropsical conditions (placental origin)
- Congenital abnormalities (foetal origin)
- Teratogens
What does ‘dropsy’ mean?
= accumulation of fluid
What are the 2 dropsical conditions?
- hydrallantois
- hydramnion
What is hydrallantois?
▪ Excess fluid accumulation in the allantois
▪ 85-90% of bovine cases
▪ Placental origin
▪ Foetus normal
▪Sporadic occurrence
▪Up to 10x expected volume of allantoic fluid
– Normal = 8-15 L
▪Fluid accumulates after mid-gestation
▪ Failure in mechanisms of production and absorption
– Excessive production, little-to-no absorption
▪Reduced number of placentomes
▪ Permanent alteration of endometrium
What is hydramnion?
▪ Excess fluid accumulation in the amnion
▪ ~10% of bovine cases
▪ Foetal origin
▪ Foetal abnormalities present
▪Related to foetal abnormalities
– Failure of swallowing or digestion of foetal fluids
– Future breeding prognosis of dam is reasonable
▪Progressive abdominal enlargement in 3rd trimester
– Slower development than hydrallantois
– Uterus and abdomen accommodates extra fluid better
– Less sick cow
– Placentomes still palpable
▪May go undiagnosed until parturition
– Large volume of thick, syrupy fluid
– Foetal abnormalities
Can hydrallantois and hydramnion occur together?
- yes occasionally
Hydrallantois prognosis
- guarded to poor
- if survives, cull of cow recommended
Hydrallantois CS
▪Bilateral abdominal distention
– Symmetrical
▪Uncomfortable
▪ Inappetant
▪Reduced/absent rumen function
– Due to compression
▪Recumbency
▪Tight uterine wall palpable per rectum
– Could potentially rupture from rectal
Tx of dropsical conditions
▪ Induce/terminate pregnancy
– Prostaglandin / steroids
– Need to provide replacement fluids to cow
-> Prevent hypovolaemia
-> Correct electrolyte disturbances
▪ Euthanasia
– Salvage slaughter if fit to travel
▪ Trochar and drain fluid
– Pass trochar into cervix
– Useful if very close to calving, otherwise would have to repeat frequently
– Rapidly re-accumulation of fluid occurs in hydrallantois
– Need to provide replacement fluids to cow?
-> ongoing debate re whether need to replace fluids
-> risk of hypovolaemic shock BUT it’s extra fluid that shouldn’t be there, so removal may not be an issue
-> IV fluids unlikely to cause harm
Congenital abnormalities
- arthrogryposis
- schistous réflexes
- congenital chondrodysplasia
- hydrocephalus
- large offspring syndrome
- cranial defects
Arthrogryposis
▪ Relatively common malformation
▪ Limb ankylosis (fusion of the joints in unusual directions)
▪ Usually combined with other congenital malformations (e.g. cleft palate)
▪ Liveborn neonates unable to stand → euthanasia
▪ Foetotomy or C-sec usually needed
Causes of arthrogryposis
Genetic
- Autosomasal recessive in Charolais breed
-> Arthrogryposis, cleft palate, scoliosis (spinal twist), kyphosis (spinal rounding)
Viral infection in utero
- Schmallenberg virus
-> Arthrogryposis affecting multiple neonates in same year
->Sheep, goats and cattle all affected.
- Bluetongue virus
-> Ruminants and camelids affected.
->Abortion is more common.
- Akabane virus
-> Not reported in UK
- Viruses are the most common cause, esp if multiple animals affected
Teratogenic plants
- Lupines (not all species)
-> Contain anagyrine.
-> Congenital deformities occur in cattle if ingested between d 40 and 70 of gestation
-> USA.
Schistosomus reflexus
▪‘Inside out’ foetuses ▪Rare, fatal malformation
– Likely genetic
▪Foetotomy or C-sec
▪Be careful not to confuse with uterine rupture
▪ Good CE and vaginal exam will differentiate between this and uterine rupture
Congenital chondrodysplasia
▪‘Bulldog’ calves
– Short legs
– Domed head
– Brachygnathia inferior (undershot jaw)
▪Dexters, Holstein, Jerseys – Likely genetic
– Other breeds reported
▪Does not always = dystocia
