First opinion equine reproduction

Question 1

Oestrus

Answer 1

5-7 days

Receptive to stallion, shows oestrus behaviour

Cervix is relaxed, pink, and oedematous

Uterus is oedematous and lacking in tone

Ovaries show waves of follicular activity and formation of dominant follicle

Question 2

Dioestrus

Answer 2

14-17 days

Not receptive to stallion

Cervix is tight and pale

Uterus is toned with no oedema

Ovaries show a lack of follicular activity and a CL

Question 3

Uterine oedema appearance on ultrasound

Answer 3

Cart wheel appearance on cross section view of uterus

Grade from 1-4 (1 is least oedematous, 4 is pathologically oedematous)

Useful to track progression of oestrus

At peak oestrus it looks like a rosette or segments of an orange

Question 4

Follicle appearance on ultrasound

Answer 4

Anechoic structure on ovary

Diameter measurements are used to track growth and aid predilections of ovulation

Average growth 2-3mm per day

Question 5

Corpus luteum appearance on ultrasound

Answer 5

Hyperechoic structure on ovary

Post ovulatory structure

Responsive to Prostaglandin when mature >5 days

Question 6

Corpus haemorrhagicum appearance on ultrasound

Answer 6

Similar to CL with a central lacuna

Forms immediately post ovulation in a high proportion of mares

Not responsive to PG

Question 7

Anovulatory follicles appearance on ultrasound

Answer 7

Variety of appearances: snow globe, spider web, honeycomb

Follicle has grown but not ovulated, give PG injections to break down

Question 8

Granulosa cell tumour appearance on ultrasound

Answer 8

Honey comb structure

Opposite ovary is smaller in comparison

Confirm with blood tests - anti-mullerian hormone is most widely used

Question 9

Altrenogest (PO or IM)

Answer 9

Suppression/prevention of oestrus during anoestrus (e.g. if competing)

Control the time of initiation of oestrus

Synchronisation of ovulation

Question 10

Oxytocin (IM or IV)

Answer 10

Induces contraction of myometrium; useful for treatment of endometritis and retained foetal membranes

Milk let down

Inducing parturition at the end of pregnancy (difficult and not routinely performed)

Question 11

Prostaglandin (IM or IV)

Answer 11

Induce luteolysis for control of oestrus in stud management

Termination of pregnancy prior to day 35

Establishing oestrous cycles in barren/maiden mares

Fostering (large IV dose)

Treatment of RFM and endometritis

Question 12

Ovulation induction agents

Answer 12

Desorelin
hCG

Question 13

Use of reproductive ultrasonography

Answer 13

1. Tracking oestrus to time insemination or breeding
2. Post insemination scan
3. 14 day scan
4. 28-30 day scan

Question 14

Using ultrasound to track oestrus to time insemination/breeding

Answer 14

Every day or every second day
Note uterus (oedema pattern), follicles, cervix
Map cysts

Question 15

Post insemination scan

Answer 15

Check for ovulation
Double ovulation? Increased risk of twins
Check for any uterine fluid (amount, nature)

Question 16

14 day scan

Answer 16

Pregnant or not
Ensure no twins (how many CLs?)
Twin pinching can be done up to day 17

Question 17

28-30 day scan

Answer 17

Still pregnant?
Heart been visible from day 25

Question 18

Pre-breeding screening tests

Answer 18

1. CEM in the mare
2. CEM in stallion
3. EVA
4. EIA

Question 19

Vaccinations for pregnant mare

Answer 19

EHV 1 and 4

Rota virus

Tetanus

Equine influenza

Question 20

EHV 1 and 4 vaccine schedule for pregnant mare

Answer 20

Prevention of respiratory disease and abortion NOT neurological disease

1st vaccine: 5th month
2nd vaccine: 7th month
3rd vaccine: 9th month

Question 21

Rota virus vaccine schedule for pregnant mare

Answer 21

Prevention of foal diarrhoea
Recommend if stud has been previously affected by rotavirus

1st vaccine: 8th month
2nd vaccine: 9th month
3rd vaccine: 10th month

Question 22

Tetanus vaccine for pregnant mare

Answer 22

Not needed anymore but clients ask for it for peace of mind

Booster 4-6 weeks prior to due date

Question 23

Equine influenza vaccine for pregnant mare

Answer 23

Keep up to date with annual vaccination

Question 24

Worming the pregnant mare

Answer 24

Wormed with Ivermectin or pyrantel 4-6 weeks before foaling down

Moxidectin can now be given, used to treat encysted redworm in winter, if due to foal in jan/feb recommended worming 4-6 weeks before due

Question 25

Worming the foal

Answer 25

Should NOT be wormed before 2-3 months

Then wormed with fenbendazole at 2-3 months and again at 5-6 months

FEWC from 6 months (2monthly)

Moxidectin not for foals <7months but after that all foals should be given it in winter

Question 26

Placentitis management

Answer 26

Signs: 9-11months pregnant, premature mammary development, running milk, vaginal discharge

Diagnostics: rectal US, blood work

Treatment: antibiotics, NSAID, altrenogest

Potential sequelae: abortion, ‘red bag’ delivery

Question 27

Retained foetal membrane management

Answer 27

History: foaled 4 hours previous, assisted foaling, has not passed placenta

Emergency!

Full clinical exam, once out ensure all placenta is present

Treatment: tie up retained membranes, ensure none has broken off, uterine flushing, do not pull!, oxytocin

Potential sequelae: metritis, laminitis