Periparturient problems in the mare

Question 1

Pre-parturient colic is common in mares in their late term. They can get normal colic or specific ones to pregnancy. Name 2

Answer 1

Foal movement colic
Uterine torsion
Ischaemia, necrosis or rupture of caecum and colon

Question 2

What is the treatment for foal movement colic?

Answer 2

Medical analgesia - buscopan, phenylbutazone

Question 3

What causes ischaemia, necrosis and rupture of the caecum and colon in pregnant mares?

Answer 3

Foal weight causes pressure on viscera

Stretches blood vessels

Question 4

Uterine torsion causes signs of colic and is usually in the last trimester of pregnancy. How is it diagnosed?

Answer 4

Rectal palpation

Question 5

How is uterine torsion treated in horses?

Answer 5

Surgery - flank or midline laparotomy

Rolling under GA not recommended

Question 6

Why do some mares develop ventral oedema in late pregnancy?

Answer 6

Foal compression of lymphatic vessels

Question 7

What is the treatment for ventral oedema in late pregnancy?

Answer 7

None - will self-resolve after foaling

Question 8

Pre-pubic tendon rupture is due to foetus’ weight. Is it common in older or younger mares? What are the clinical signs?

Answer 8

Older mares
Colic signs
Large painful oedema continuous with udder ‘dropped udder’
+/- bloody discharge in milk

Question 9

What is the treatment for pre-pubic tendon rupture in mares?

Answer 9

Analgesia (phenylbutazone)

Assistance with foaling +/- caesarean

Question 10

What is hydrops amnion/allantois?

Answer 10

Excess fluid in amniotic/allantoic space

Question 11

Hydrops amnion/allantois causes colic, dyspnoea, recumbency and even circulatory collapse. What effect does it have on the foal?

Answer 11

Deformed foals

heritable?

Question 12

How is hydrops amnion/allantois diagnosed?

Answer 12

Rectal exam - huge fluid filled uterus out of reach

Question 13

How can hydrops allantois/amnion be treated?

Answer 13

Induce foaling/abortion
Drain fluid off slowly via cervical dilation/foal removal
IV fluids to maintain systemic BP

Question 14

What causes placentitis? Give examples of bacteria

Answer 14

Ascending infection from the cervix

Streptococcus, E. coli, Aspergillus

Question 15

Placentitis eventually leads to abortion. What clinical signs suggest placentitis?

Answer 15

Placental thickening on ultrasound

Cervical swabs of discharge

Question 16

A pregnant horse has premature udder development, lactation and vaginal discharge although she is not near term. What is your diagnosis?

Answer 16

Placentitis

Question 17

What is the treatment for placentitis?

Answer 17

TMPS or other potentiated sulphonamide

Phenylbutazone

Question 18

What is the most common cause of vaginal bleeding in a horse? It is more common in pregnant or older mares

Answer 18

Varicose veins

Question 19

What is the treatment for varicose veins leading to vaginal bleeding?

Answer 19

No treatment required

Usually no concern to mare

Question 20

Can NSAIDs be used in pregnant mares?

Answer 20

Yes - may be necessary to give phenylbutazone

Weight of foal can exacerbate ortho disease

Question 21

What respiratory stimulant can be given to foals following dystocia?

Answer 21

Doxapram

Question 22

If during a vaginal exam for dystocia you discover a foal is able to pass per vaginum, how long should you leave a mare with no progress before starting a caesarean?

Answer 22

15 mins

If no progress with dystocia

Question 23

A mare has become suddenly unwell with a distended abdomen. She is definitely pregnant, but you cannot feel the foal on rectal exam in the uterus or in the birth canal. What is your most likely diagnosis?

Answer 23

Complete uterine rupture

Foal in abdomen so cannot feel via rectum

Question 24

What is the treatment for a complete uterine rupture or tear?

Answer 24

Consider removing foal and euthanasia of mare

Ex-lap and repair

Question 25

Why are uterine tears a problem?

Answer 25

They can cause haemorrhage and lead to peritonitis

Question 26

How can uterine ruptures or tears be diagnosed?

Answer 26

Ultrasound Rectal/vaginal exam Peritoneal tap

Question 27

Perineal lacerations are common during foaling. Most minor tears heal spontaneously. What should treatment be for 3rd degree perineal lacerations or rectovaginal fistulas?

Answer 27

DELAYED surgery - wait for granulation tissue to form | If don't wait --> wound breakdown

Question 28

How are cervical lacerations treated? Do these affect fertility?

Answer 28

May heal spontaneously or require surgery Delay repair for 1 month until uterus involuted and inflammation has decreased May become sub-fertile

Question 29

What is the treatment of post-partum 'uterine cramp' colic?

Answer 29

Analgesia - buscopan, phenylbutazone

Question 30

Why are mares predisposed to colonic torsion post-partum and how is this treated?

Answer 30

Increased abdominal space | Surgical colic - requires fast correction or fatal

Question 31

Rupture of the uterine artery is common in older mares. How is this diagnosed?

Answer 31

Colic signs - may progress to shock Rectal palpation of broad ligament Ultrasound

Question 32

Rupture of the uterine artery may cause haemorrhage into the broad ligament or into the abdomen if the broad ligament also ruptures. How can ruptured uterine arteries be treated?

Answer 32

Keep quiet +/- sedation Analgesia Clotting agents IV floods or blood transfusion

Question 33

Uterine prolapse may occur after a difficult foaling or if the mare is exhausted. How is this treated

Answer 33

Clean and replace under epidural Give oxytocin once placed (causes involution) Broad spectrum ABs + flunixin

Question 34

On average mares pass foetal membranes within how many hours of foaling? After how long is the placenta classed as retained?

Answer 34

``` Average = 2 hours Retained = >4 hours ```

Question 35

Describe how retained foetal membranes can cause laminitis and be fatal

Answer 35

Decompose and cause metritis | Cause endotoxaemia/SIRS - severe laminitis and death

Question 36

What initial medical treatment should be given for retained foetal membranes?

Answer 36

Oxytocin Flunixin Broad spectrum antibiotics Check tetanus cover

Question 37

If medical treatment for RFM doesn't work, the membranes can be manually removed (controversial). What should you do if the entire foetal membranes are removed?

Answer 37

Antibiotics + NSAIDs | Only re-examine if necessary!

Question 38

If medical treatment for RFM doesn't work, the membranes can be manually removed (controversial). What should you do if the removal is incomplete and some foetal membranes remain?

Answer 38

``` Lavage Administer oxytocin Put on ABs and flunixin Re-examine Continue lavaging until uterus involuted and little fluid returned ```

Question 39

A horse post-foaling prevents recumbent, with muscle fasciculations and diaphragmatic flutters (thumps). This condition is rare compared to other species. What are your most likely DDx?

Answer 39

Hypocalcaemia (Tx: give calcium diluted in saline) | Tetanus (only if not UTD with vaccine)

Question 40

Why is hand reared foals not recommend?

Answer 40

Hand-reared foals develop socialisation/behavioural problems | Adults can be extremely dangerous

Question 41

What should mares be screened for via a clitoral swab/blood test prior to mating?

Answer 41

Contagious equine metritis (Taylorella equigenitalis) - swab EHV - blood Equine infectious anaemia - blood