Repro Flashcards
Common causes of dystocia in NWCs
- Foetal malpresentation (most common)
- Uterine torsion (well represented in the literature)
- Poor cervical dilation
Which horn do >95% pregnancies implant in
the LEFT
Clinical features of uterine torsion
Typically occurs in late gestation, >9mo (like mares although often occurs at term in mares/cows)
The torsion may occur in the uterine body, just cranial to the cervix, or in the vagina caudal to the cervix (NB horses tors in the uterine body, cows in the vagina)
Torsion can be described as clockwise or anti-closkwise
Left horn pregnancy typically undergoes clockwise torsion, right anticlockwise (seems counterintuitive to me based on gravity?)
NB can occur in either direction w either horn so need to be confident which way on rectal
Can be anywhere from 90° to 360° or more
Diagnosing uterine torsion
- Vaginal exam - palp or spec: for observation of twisting/narrowing of the vaginal vault (NB this is NOT an appropriate dx test in the mare as 1) torsion always occurs cranial to the cervix and 2) high risk of ascending placental infection
- Rectal exam - superior to vaginal as takes into account torsions occuring cranial to cervix. Dx based on deviation of the broad ligaments; A taut broad ligament is palpable, coursing transversely in the direction of the torsion
- Ex lap
Treatment options for uterine torsion
Non-surgical = rolling; place in lateral on the same side as the torsion ie RLR for clockwise torsion. Maintain pressure on the fortus and roll into dorsal, then onto the other side (can repeat upto 3 times)
Surgical = flank laparotomy - usually left sided
NB the camelid spleen is located mid left flank, unlike cattle, so can be injured on abdominal entry
8-10cm incision for torsion correction; extend to 15cm if caesar as well.
Expected outcome for uterine torsion tx
Non surgical correction sucessful in approx 65%, remaining 35% req. surgery (out of a series of 20)
Of those 20 - 70% live crias
Expect maternal survival >80% and foetal survival >70%
Leave the foetus in situ if torsion is sufficiently pre-term to compromise extra-uterine survival. If term pregnancy, compromised or dead foetus, caesarean should be performed concurrently
Average and range of gestation length
Ave 343 days
Range 11.5-12mo (can go over a year but not common)
Length of stage 2 labour
Ave 15 mins (range 10-30) - quick and explosive like the mare
Requirements for nonsurgical management of dystocia
1) Adequate cervical dilation
2) Pelvis of adequate diamter to allow passage of foetus and manipulations
3) Sufficient room in the uterus for foetal manipulation
Indications for caesarean
1) Inadequate cervical dialtion
2) Small maternal size precluding manipulations
Surgical approaches for caesarean section
Left paralumbar approach (preferable)
Ventral midline approach
Advantages of left PLF approach for caesarean
1) Can be done sedated and restrained - ventral midline req GA
2) Improved foetal vitality and post-partum milk let down vs following GA
What dose of lidocaine for local anaesthesia shouldn’t be exceeded in camelids
4mg/kg
Organs that can be inadvertently lacerated during left flank approach
C1, spleen, left kidney
Unlike in ruminants, the spleen is positioned against the left body wall in the region of the flank
Organs which may be inadvertantly lacerated during right flank approach
C3, duodenum, other pars of SI, right kidney
Recommeded uterine closure technique (suture size, type, pattern)
Single layer suitable for most healthy camelids
USP 0 PDS or poliglycaperone in inverting pattern
2 layers recommended if there is any mural haematoma/compromise
Advantage of ventral midline laparotomy approach for caesar
Lower risk of incisional herniation vs flank incisions
NB this is contrary to the situation in other spp where midline incisions are more likely to hernaite than flank (ie horse)
Disadvantage is requirement for GA
Complications following caesarean (
1) Haemorrhage
2) Peritonitis
3) Incisional complications - seroma, infection, herniation (latter more common with flank vs ventral midline contrary to horses)
4) Uterine adhesions
5) RFM - rare after normal delivery in camelids but common after caesar -> often cant remove at surgery
Expected return to breeding soundness following caesarean
75%
Which accesory sex glands are present in the male Camelids
Prostate & bulbourethral, but NO seminal vesicles
Peculiarities of the male camelid reproductive tract
- Pre-scrotal sigmoid flexure
- Glans is long in the adult male - 9-12cm; tapering at tip to merge into a firm cartilagenous projection with a slight clockwise curvature
- Penis penetrates cervix as in horses
- The SAC prepuce is triangular and points caudally in the nonerect penis; urine is projected backward between the hind limbs from a semisquatting position
- With arousal - cranial preputial mm pull the prepuce cranially
- Cranial and caudal preputial mm arise from the cutaneous trunci mm
- Juvenile males have adhesions between the prepuce and the glans, making penile extrusion impossible until 2-3 yrs old
- If castration is performed before pubherty, adhesions may only be partaially released or not at all (this is similar to foals in which the internal lamina of the prepuce and free portion of the penis are fixed into a single lamina, separates under androgenic control)
- Urethral catheterisation is difficult in neonates as can’t fully extrude the penis
- Cartilagenous tip of the penis is not present in neonates
- Attempts to peel prepuce from the glans will rx in haemorrhage
- Impossible to catheterise mature animals retrograde as urethral diverticulum is rarely avoidable
- Camelids have bulbourethral (cowpers) and prostate gland - no seminal vesicles
- The head of the epididymis is cranial-ventral and the tail caudal-dorsal as it is in the boar but not in the bull, ram, and stallion, where the head of the epididymis is dorsal
True of flase, femal camelids are induced ovulators
True
Unique feature of camelid placentation
- Development of an extra membrane of foetal epidermal origin - an opaque white membrane 1-2mm thick covering surface of foetal body, head neck & limbs at/close to full term
- Attached to neonate at MC junctions incl lips, anus, vulva, perpuce, footpad-skin junction, coronet and umbilicus
- Friable & easily torn/brushed from surface & withers soon after parturition
- Contrasts amnion of most other spp which completely envelops nose & mouth, potentially suffocating the weak neonate
- Membrane is stratified squamous epithelium with an outer keratinised layer
- Most will be deliverd with the membrane intact; may disintegrate w dystocia
- Precise function unknown; other mammals float freely in amniotic fluid whereas in camelids, EM separates skin from amniotic fluid, except at all orifices so waste products are deposited directly into amniotic fluid like other spp
- EM not observed until last 2mo of gestation, before this, aborted foetuses are surrounded by amnion
Normal foetal position presentation and posture
Most common normal presentation is as for other species - cranial longitudinal, dorsosacral position and the head lying dorsal to extended forelimbs (posture)
The posterior longitudinal presentation, dorsosacral position with extended hind limbs is also normal but much less common
Abdo approach to caesarean
Usually performed in lateral or sternal. Has been reported standing but rare
Left PLF approach prob most common. Can do ventral midline but req GA (decr. Foetal vitality)
Some sx prefer ventral midline dt flank anatomy - tapers - think muscles largely present dorsally then aponeuroses more ventrally so vant use more ventral flank incisions
Follicle size considered necessary for ovulation in camelids? And considered pathologic?
>13mm pathologic
At least 7mm for ovulation to occur (induced ovulators)
Gestation length for SACs
330-360d
CSs of prematurity in crias
- CSs incl unusually low birth weight, <8kg sparks some concern for llama crias and alpacas should weigh >3.6kg
- Weak, unable to hold the head up to nurse, weak/absent suckle reflex, flexor laxity (walk on fetlock), floppy ears (immature aural cartilages), silky fibre coat, eyelids may be stuck together (>1 mo premature)
- Rubbery covering on the nail may persist >6-12hr in premature crias (1-2d), epidermal membrane is thicker and may be remnants of it for 24hr
- Incisors are erupted in normal cria, failure to do so in the days-weeks after birth is another signs of prematurity
- Premature crias also sleep a lot more than normal
- Bradypnoea (<10bpm); absolute hypercapnia fails to exert respiratory effect & PaO2 is low
- Although mature crias are often hypoglycaemic for a few hrs after birth, premature ones may remain so and lack energy to nurse and have poor thermoregulatory ability
- Leucopaenia (neutropaenia)
- Intestinal mucosa doesn’t absorb IgG
- Higher incidence of ALD dt incomplete cuboidal bone ossification
- Intra-uterine infection may simulate many of the characteristics of prematurity even at term = dysmaturity
- IgG increases to around 25g/l following colostral ingestion and decreases to 15 over the first 10d
Dx & tx of FPT in crias
Dx - Single radial immunodiffusion is the most specific lab test in calves/foals
Other methods incl TP refractometer, serum protein electrophoresis, Zn sulpate turbidity and Zn sulphite precipitation
All impractical other than refractomoter TP -
<50g/l suggest FPT, 50-60 = equivocal, >60g/L suggests adequate PT
Tx - early intervention (6hr) tube with llama or goat colostrum (most like camelids and most likely to be immunised for same dz) - almost impossible to get sufficient milk manually from the post-partum female
Plasma transfusion - either IV, intra-peritoneal or orally
Have to administer slow IV (lung oedema), IP administration is faster, 5mm skin incision in the left flank, insert blunt cow teat canula and administer warm plasma in 5-10 mins
blood, plasma or serum is preferably obtained from the dam, only option for tx of FPT >24hrs old - plasma preferable at 10-20ml/kg
What is a male & femal pseudohermaphrodite?
And true hermaphrodite?
Pseudohermaphrodite has gonads of one gender but tubular repro tract of the other
Male pseudohermaphrodite has testis but female external genitalia
Female pseudohermaphrodite has ovaries but characteristics of male external genitalia (ie named male/female based on gonadal tissue).
True hermaphrodite has both ovarian and testicular tissue
Which embryological structure does the male reproductive tract develop from?And the female tubular repro tract?
Male - Wolfian/mesonephric duct (_m_ale = _m_esonephric)
Female - Mullerian/paramesonephric duct
(Males produce AMH - inhibits Mullerian duct allowing Wolffian duct to develop)
Suggested age of castration in male camelids
Ideally >12mo but before sexual maturity
Hand reared males that imprint on humans will need castrated at around 2mo
Methods of castration
- Standing - scrotal incision, closed vaginal tunic, 1-2 ligatures & transect &/or emasculator (*smaller than for large animals), leave scrotum open
- Recumbent - either as above or via prescrotal midline incision (like dogs?) care re penis - both testicles removed via same incison w 1-2 ligatures on cord. Skin closed primarily
Site of ventral midline incision for caesarean
From just cranial to the mammary gland, cranially for approx 40cm (seems v long)!
Procedure - incision in the greater curvature of the gravid horn (usually left) and packed off from the peritoneum with wet sterile towels if poss to limit contamination. The cria is delivered and handed to an assistant for resuscitation as needed. The placenta is frequently removed with minimal traction. The uterus is closed w absorbable suture in an inverting pattern; 1-2 lauyers depending on condition of tissue.
