Equine parturition and associated problems Flashcards
Normal Pregnancy
325-365 days (335)
diffuse chorioallanotic placenta
Progesterone produced by placenta
endocrinology of parturition
48 hrs prior to parturition:
increase in foetal ACTH > steroid switch progestogens to cortisol > decrease in progestagens, increase in oestragen/prostaglandins > increase in oxytocin, relaxins and PGs >parturition
- increase in relaxin: vulval and ligament relaxation
- increase in oestrogen: cervical relaxation
- decrease in progestagen, increase in oxytocin & prostaglandin: myometrial activity
- increase in prolactin: mammary development and milk production
Prepartum changes (how you know it’s gonna happen!!!) (6)
- relaxation of sacrosciatic ligaments (gradually over last few weeks and causes dipping of gluteal muscles)
- cervical softening (30d before)
- relaxation of vulva (hours before)
- udder enlarges (2-6 weeks before)
- waxing (24-48hrs)
- temp drops by 1F due to redistribution of blood to uterus (12hours before)
High risk pregnancies
Previous reproductive problems in mare Poor perineal/pelvic conformation Poor mare health Poor nutritional condition of mare Previous abnormal foals ?When was mare last scanned after being covered? Placentitis Twins
Problems in late gestation
- placental dysfunction
- placentitis
- equine herpes virus
- uterine torsion
- other
Placental dystfunction causes (4)
Non-infectious -Premature placental separation -Twinning -Toxic Infectious -Placentitis*
Placentitis causes
Usually ascending infection
- from stallion
- form a cervix that is not fully closed.
- Haematogenous
- At time of breeding (Nocardioform spp.)
Usually bacteria, occ. fungii
Streptococcus zooepidemicus/equisimilis
E. coli, Pseudomonas spp., Klebsiella pneumoniae, Aspergillus spp. Candida spp.
Placentitis
- risk factors
- CS
Risk factors:
- Poor perineal conformation
- Faecal soiling can pool and cause ascending infection.
- Breed (TBs)
- Poor body condition
- ↑age/parity
Signs
- Vulval discharge
- Udder development/premature lactation
- Foal at risk of septicaemia
Placentitis
- diagnosis
- treatment
Diagnosis
- Ultrasonography
- microbiology
Treatment
- Antimicrobials
- NSAIDs
- Tocolytics
- Altrenogest? (regamate: synthetic progesterone that can help maintain pregnancy)
- Pentoxifylline
Foaling Stage 1:
- signs (4)
- time
- ending
preparation for foetal expulsion:
signs:
- Sweating
- restlessness
- Flehmen response (curling back of upper lip)
- mild colic
- 1-4 hrs, up to 24hrs
- Positioning of foetus: Dorsopubic to dorsosacral: Head and forelimbs form ‘wedge’ at cervix
Ends with chorioallantoic rupture
Foaling stage 2
- steps (5)
- mare
- timing
expulsion of foal
- uterine & abdominal contraction
- Commences with rupture of chorioallantois
- Loss of allantoic fluid
- Exposure of amniotic membrane
- Ends with expulsion of foal
Often recumbent, restless
<20 min
Foaling stage 3
- what
- signs (2)
- timing
- after (5)
Expulsion of foetal membranes
Uterine contractions
Mild colic
<1m
- Check for excessive twisting
- Check endometrial surface for thickening
Prediction of parturition
- kits to test mammary secretions
- signs
- CCTV
- normally after 6pm
- when was mated
Treatment of dystocia
- preparation
- procedure (4)
Preparation:
- Clean perineum
- Epidural: between C1 and C2: elevate tail head to palpate space
- Sedation?
- Tocolysis – clenbuterol
Procedures:
-1st – Assisted vaginal delivery (AVD)
-If unsuccessful, GA and:
Controlled vaginal delivery
Hindlimb elevation
-If unsuccessful over 15min:
Foetotomy
If foal confirmed dead
-If unsuccessful after 1-2 cuts:
Caesarian section
Rapid technique required
peri-partuerient problems
- haemorrhage
- RFM
- uterine tears
