Peri –Parturient Problems in the Mare Flashcards
List the pre-parturient problems seen in mares
- Colic
- The over-large mare: ventral oedema, pre-pubis tendon rupture
- Placentitis
- Varicose veins
- Orthopaedic disease
List the parturient problems seen in mares
Dystocia
Uterine rupture
Uterine tears
Cervical tears
Perineal tears
List the post-parturient problems seen in mares
Colic
Uterine prolapse
Rectal prolapse
Retained placenta
Metritis
Hypocalcaemia
Tetanus
Describe pre-parturient colic
- Treating colic in the pre-parturient mare can be diagnostically and therapeutically challenging.
- Colic is not uncommon in late-term mares
- As well as all the “normal” types of colic, there are colics specific for pregnancy.
- Some pregnancy-specific colics have a poor (or worse) prognosis
Why is investigation of colic harder when it presents pre-parturiently?
- Investigation is hampered by the presence of a large foal – this makes rectal examination, abdominal ultrasound and abdominocentesis more difficult and less useful.
- Heavily pregnant mares are poor candidates for general anaesthesia
- Exploratory laparotomy hampered by presence of foal
List the different pregnancy specific colic seen in mares
- ‘Foal movement’
- GI colic
- Actually foaling or aborting
- Ischaemia/necrosis/rupture of caecum and colon
- Uterine torsion
Describe ‘foal movement colic’
- Mild-moderate medical colics –caused by intra-uterine movement of the foal?
- Common
- Should respond to mild/moderate analgesia (buscopan or phenylbutazone)
How can you tell apart colic from actually foaling or aborting?
Vaginal exam - is the cervix open?
Describe colic due to ischaemia/necrosis/rupture of caecum and colon in mares
- Syndrome of ischaemic necrosis of colon/caecum potentially ending in rupture.
- Due to weight of foal applying pressure to viscera or stretching visceral blood vessels
- Difficult to diagnose definitely – look for signs peritonitis/endotoxaemia
- Even more difficult to manage – lesions maybe inaccessible at exploratory laparotomy
How is colic due to uterine torsion diagnosed?
Rectal palpation – palpate one tight broad ligament
Vaginal exam not helpful – unlike cattle, twist cranial to cervix
How is colic due to uterine torsion treated?
Surgery
Standing flank laparotomy
GA and midline laparotomy (± caesarean?)
Rolling under GA – not recommended
Describe ventral oedema seen in pre-parturient mares
- Some mares develop a large plaque of ventral oedema near term.
- This maybe due to compression of lymphatic drainage by foal.
- If mare is well and oedema uniform and non-painful – then no treatment required – will resolve post foaling.
- Important to differentiate this from other causes of abdominal enlargement.
Describe the signs of pre-pubic tendon rupture in mares
- Large plaque of painful oedema, continuous with udder (“dropped” udder).
- Maybe bloody discharge in milk
- Often gives colic signs
- Mare often spends more time recumbent.
How is pre-pubic tendon rupture in mares treated?
- Analgesia = bute
- Will need assistance with foaling – cannot use abdominal press. Caesarean?
- Will resolve if mare nursed through to foaling, however often progressively becomes more painful and results in euthanasia.
- If survives – do not breed from again!
Describe Hydrops amnion/Hydrops allantois in the pre-parturient mare
Excessive fluid in allantoic/amniotic space
Up to 200 litres have been recorded
What are the signs of Hydrops amnion/Hydrops allantois in the pre-parturient mare?
May eventually cause colic, dyspnoea, recumbency, circulatory collapse.
Foals usually deformed. Heritable?
How is Hydrops amnion/Hydrops allantois in the pre-parturient mare diagnosed?
Rectal exam – huge fluid filled uterus but foal out of reach
How is Hydrops amnion/Hydrops allantois in the pre-parturient mare treated?
Induce foaling or abortion
Dilate cervix, drain fluid off slowly
Manually remove foal
IV fluids to maintain systemic blood pressure?
What is the main consequence of placentitis?
Eventually leads to abortion
What is the cause of placentitis?
Ascending infection from cervix
Strep. spp., E.coli, Aspergillus.
How does placentitis present?
Premature udder development and lactation ± vaginal discharge
How is placentitis diagnosed?
Clinical signs
Ultrasonographic demonstration of placental thickening
Cervical swabs if discharging
How is placentitis treated?
Potentiated sulphonamides
Bute
What is the most common cause of vaginal bleeding in the horse?
Varicose veins
How are varicose veins managed?
Usually no treatment required – tend to be of more concern to owner than mare
Describe orthopaedic disease in pre-parturient mares
- Extra weight/ bulk of late pregnancy can substantially exacerbate the effects of orthopaedic disease – arthritis, laminitis etc.
- Despite frequent owner concerns over of use of Nsaids in pregnant mares, use of daily phenylbutazone maybe necessary to keep some mares going.
What equipment should be prepared when going to a dystocia case?
- Sedation (and ketamine?)
- Clenbuterol or buscopan
- Local anaesthesia (epidural)
- Doxapram
- Foaling ropes
- Lubricant
- Hibiscrub
- Needles/syringes
- Waterproofs
Once at the place with the foaling mare with dystocia describe the steps to take to handle this case
- Warn owner – guarded prognosis – may lose both mare and foal
- Restrain mare (sedation? Twitch? Clenbuterol?)
- Quickly check mare not in shock /haemorrhaging.
- Clean perineum/arms
- Vaginal exam – with plenty of lubricant
- Ascertain presentation/posture/position
7.Decide if vaginal delivery possible – if not refer for caesarean or euthanase
If a foaling mare makes no progress after … reassess the situation?
15 minutes
Describe uterine tears/ruptures during parturition
- In complete ruptures the foal may fall into the abdomen and not be palpable in the birth canal.
- In these cases the mare may fatally haemorrhage, or will develop fulminating peritonitis and fatal endotoxaemia .
- Extract the foal and consider euthanatising the mare.
- Smaller tears may not be noticed and only suspected when the mare shows sign of peritonitis after foaling. These have a better, but still guarded prognosis.
How are uterine ruptures/tears during parturition diagnosed?
Clinical signs
Rectal/vaginal examination
Ultrasonography
Peritoneal tap
Describe perineal lacerations during parturition
- Minor perineal lacerations are common during foaling.
- Many will heal without intervention.
- Lacerations which substantially disrupt the perineal anatomy should be repaired, especially if natural healing will alter perineal conformation.
- This maybe done immediately, or delayed for a few days if bruising is severe.
- Administer antibiotics/Nsaids/tetanus cover
What is a third degree perineal laceration?
Where foals foot has penetrated rectum and torn through anus.
Rectum, vulva and vagina all communicate
How is a third degree perineal laceration treated/managed?
- Do not repair immediately – will break down
- Administer antibiotics/Nsaids/tetanus cover
- Repair required if mare to conceive again!
- Delay surgery for 4-6 weeks until granulated in.
- Surgery difficult, several attempts often needed before complete repair occurs.
List the types of post-partum colic seen
- ‘Uterine cramps’
- GI colic
- Ischaemia/necrosis/rupture of caecum and colon
- Inversion of uterine horn
- Colonic torsion
- Rupture of uterine artery
Describe post-partum colic due to ‘uterine cramps’
Many colics soon after foaling are put down to post-partum uterine contractions.
Mild to moderate colics, no sign endotoxaemia.
Should resolve with buscopan or phenylbutazone.
Describe post-partum colic due to inversion of the uterine horn
- After forceful foaling or too forceful removal of retained membranes
- Colic which reoccurs despite analgesia
- If mare continues to strain may proceed to uterine prolapse
- Diagnosis by vaginal and rectal exam
- Treat with analgesia, smooth muscle relaxants (buscopan/clenbuterol), manual replacement, uterine lavage.
Describe post-partum colic due to colonic torsion
Post-partum mares prone to colonic torsion
Due to sudden increase of space in abdomen post foaling?
A surgical colic and rapidly fatal unless quickly corrected
Describe post-partum colic due to rupture of the uterine artery
- More common in older mares.
- Haemorrhage may occur into broad ligament or into abdomen
- Mild to moderate colic signs, which may progress to signs of haemorrhagic shock.
- May not respond well to Nsaids – painful?
- May be contained within broad ligament, but if this ruptures or mare is haemorrhaging directly into abdomen then is likely to be rapidly fatal.
How is post-partum colic due to rupture of the uterine artery diagnosed?
Gentle palpation of broad ligament per rectum
Abdominal and rectal ultrasonography.
How is post-partum colic due to rupture of the uterine artery treated?
Keep quiet – sedate?
Analgesia
IV fluids – judiciously
Blood transfusions
Describe post-partum uterine prolapse in mares
- Uncommon.
- After excessive traction on foal or retained membranes.
- After difficult foaling or if mare exhausted
- May rupture uterine vessels and cause fatal internal haemorrhage.
- Even after replacement, death from metritis/endotoxaemia not uncommon.
How is post-partum uterine prolapse in mares treated?
- Clean uterus.
- Replace under epidural anaesthesia.
- Give oxytocin once replaced
- Treat with broad spectrum antibiotics and Nsaids for anti-endotoxic effects
When are foetal membranes classed at retained?
- On average mares pass the foetal membranes within 2 hours post foaling.
- Over 4 hours is considered abnormal.
- When intervention should take place is controversial – if still retained 4-6 hours post foaling then most stud vets advise treatment.
What are the consequences of retained foetal membranes?
If left in place the membranes decompose rapidly, produce a metritis which induces endotoxaemia, which may lead to severe laminitis and death.
Describe how to treat retained foetal membranes
- Administer oxytocin, broad spectrum antibiotics, flunixin for anti-endotoxic effects and check tetanus cover.
- Oxytocin alone maybe enough to quickly stimulate passage of the membranes (If this does not work then further treatments are highly controversial)
- Manual removal controversial
-If a retained fragment exists and cannot be located and removed then the uterus should be lavaged until the recovered fluid is running fairly clear. Use clean tap water initially.
Describe post-partum metritis in mares
- Maybe due to unnoticed partial retention of placenta or due to contamination of uterus during foaling
- May cause fatal endotoxaemia ± laminitis if untreated
- Treat as by antibiotics, Nsaids, oxytocin and lavage exactly as described for RFM
Describe post-partum hypocalcaemia in mares
- Uncommon (c.f. cattle)
- Muscle fasciculations, recumbency, tetany, Diaphragmatic flutter “thumps”
- Give calcium diluted in saline
How are orphaned foals managed?
You will need (before the orphan appears):
- Foster mare ( Newmarket Foster mares Ltd)
- A source of colostrum
- A milk replacer
- Bottle/teat
- Feeding protocol
Describe the main considerations of orphaned foals
- Hand-rearing foals is not recommended
- Expensive
- Hugely time consuming
- Growth problems common
- Socialisation and behavioural problems
- Adult hand-reared horses can be exceptionally dangerous
