Pathology of parturition in large animals Flashcards
Pathological delivery (dystocia) is in latin
difficult delivery = partus gravis seu difficilis
for expulsion of the fetus help is needed (obstetrical aid)
Stillbirth in latin
partus mortuus
dead, but in normal presentation fetus will be expelled without any aid
Retention of fetal membranes (RFM) in latin
retensio secundinarum
fetal membranes are not expelled during normal time after delivery of fetus.
Main causes of dystocia in cattle. (6)
In cow according to frequency:
- Fetus and birth canal (pelvis) disproportion (especially in first time calvers).
- Fetal malpresentation, malpositions and malpostures e.g. posterior presentation.
- Uterine torsion
- Uterine inertia (low contraction activity)
- Twins (when in same horn, one is always posterior positioned)
- Fetal monsters, fetal membranes pathology
Fetal presentation in the context of parturition:
The relationship between the long axis of the fetus and the long axis of the maternal birth canal.
Thus presentation can be longitudinal (anterior or posterior), transverse, or (very rarely) vertical.
Fetal position in the context of parturition:
That surface of the maternal birth canal to which the fetal vertebral column is applied.
Thus position can be dorsal, ventral or lateral (right or left).
Fetal posture in the context of parturition:
The disposition of the head and limbs of the fetus.
Broad causes of dystocia, extrinsic (4) and intrinsic (4).
extrinsic or environmental:
diet (excess condition and poor condition both)
supervision (ppl disturbing natural birthing too much)
diseases e.g. hypocalcemia
induction of birth
intrinsic:
age
parity
body weight
pelvic size of dam
obstetrical snares
(rope version of obstetrical chains)
obstetrical forks
snare guides in order to place snares on parts of the calf within the uterus
Eye hooks and their connection with obstetrics string by one snare (A) and separately (B).
Obstetrics ring knife
Krey-Schöttler’s double –jointed hooks for use only in dead calves
Mechanical calf puller
Correct placement of obstetrical chains.
Always Place a chain loop around the leg just above the fetlock (ankle), plus a half-hitch just above the hoof.
Main rules for obstetrical aid, first 7 rules.
- Asepsis and the use of antiseptics.
- Avoid the manual rupture of the fetal membranes before the cervix is totally open.
- Start the obstetrical aid only after you know the exact cause. Aid should be given according to a specific plan and if that plan
does not work within 20 minutes, we should change the plan. - It is much easier to give obstetrical aid in a standing animal versus in a recumbent animal. In recumbent animals, the aid is easier when limbs are malpostured or head is in upper position.
- Life saving (mother and fetus). Inspect general status of the animal.
- Lubrication
- If there is more than 2 limbs in birth canal, check whether they are front or hind limbs and whether they belong to the same fetus.
Main rules for obstetrical aid, second set of rules (rules 8-14).
- Obstetrical snares are placed separately onto each leg, if necessary, the head will be fixed with a third snare. With twins, the obstetrical snares should be labeled.
- For traction of the fetus, maximum 4 person power is used. Traction should be even and should be done only during the cow’s contractions.
- If the birth canal is narrow & bony, do not use excessive force. Do cesarean section or fetotomy instead.
- All corrections of malpositions or postures should be done in utero, not in the vaginal canal (no space for that). The fetus should be pushed back into uterus between contractions.
- Always do a final check when obstetrical aid is completed. Check for injuries and bleeding.
- Fetotomy only in case of dead fetuses and emphysemic fetuses.
- Communication with owner is very important.
For successful delivery in heifers, the external distance between coxal tubers should measure at
minimum 40 cm at insemination.
Height of the heifer’s back should be minimum 120 cm at insemination.
cow gestation in days
283 days
Relatively large fetus (fetus magnus relativus)
versus
Absolutely large fetus (fetus magnus absolutus)
Relatively large fetus: fetus size is normal, but birth canal is narrow.
Absolutely large fetus: fetus size is too big, birth canal size is normal and birth canal is normally open (most frequent cause for difficult delivery in cow).
Application of calving ropes to what part of the calf?
A = to the head, B = to the leg
Malpostures in anterior presentation. Describe deviation of the head:
Happens frequently (ca 49%) and is frequently right side deviation
Side deviation of the head common (lateroflexio capitis dextra, sinistra)
Always according to cow flank not the fetus flank
Caused by: incomplete opening of the cervix (premature rupture of fetal membranes, weak fetus (cannot extend head into the birth canal)
May happen during assisted calving, during traction of the fetus when the head is not inserted into birth canal.
E.g. Calf neck ankylosis, hydrocephalus, dead fetus
Clinical signs of malposturen of the calf’s head in anterior presentation.
Hoof tips are visible from the vulva, hoof plantar surface is downward, leg on the side of the head deviation is less visible.
Possible to palpate the head and nose, but if the uterus is strongly contracted around the fetus we can feel only ear tips.
If head deviation is corrected in the wrong way (downward), it can result in neck torsion and fetal death.
