Week 8- Infertility in the Mare

Question 1

What is the average length of a mare’s estrous cycle

Answer 1

21 days including 3 to 7 days of oestrus and 14 to 15 days of dioestrus

Question 2

When does ovulation typically occur during estrus

Answer 2

About 24 hours before the end of oestrus marking the optimal breeding window

Question 3

What type of breeders are mares

Answer 3

Seasonally polyoestrous long day breeders meaning they cycle during spring and summer

Question 4

What percentage of healthy young mares typically conceive per cycle

Answer 4

Up to 90 percent showing high natural fertility rates

Question 5

When should infertility investigation begin in a mare

Answer 5

After she fails to conceive after three oestrous cycles in one breeding season

Question 6

What is the target pregnancy rate per cycle in a breeding operation

Answer 6

Greater than 65 percent as a measure of reproductive efficiency

Question 7

What is the ideal end of season pregnancy rate

Answer 7

Around 85 percent showing successful management across cycles

Question 8

What is a good live foal rate for a stud

Answer 8

Greater than 75 percent representing overall breeding success

Question 9

What is one of the most common reasons mares do not show heat

Answer 9

Pregnancy but other causes include seasonality and body condition

Question 10

What is foal heat and why is it sometimes silent

Answer 10

The first heat after foaling which can be behaviourally subtle and easily missed

Question 11

Why might lactational anoestrus occur in mares

Answer 11

Because high prolactin levels during lactation can suppress the reproductive axis

Question 12

What historical factors are important in assessing mare fertility

Answer 12

Previous pregnancies breeding method uterine infections and use of hormones

Question 13

What is the significance of evaluating perineal conformation

Answer 13

Poor conformation can allow air and contaminants to enter the reproductive tract

Question 14

What is the ideal vulval conformation in a fertile mare

Answer 14

Vulva vertical or less than 10 degrees off with 80 percent below pelvic brim and a tight seal

Question 15

What does pneumovaginum refer to

Answer 15

Ingress of air into the vagina often due to poor vulval seal which can lead to infection

Question 16

What breeds or types of mares are more prone to pneumovaginum

Answer 16

Large breeds aged mares and those that have had multiple foals

Question 17

What is the purpose of a Caslicks procedure

Answer 17

To surgically close the upper vulva and improve the vulval seal to reduce contamination

Question 18

What must be done to a Caslicks suture before foaling

Answer 18

It must be released to prevent tearing during delivery and often reclosed postpartum

Question 19

What is a vestibuloplasty used for in mares

Answer 19

To restore both the vulval and vestibulovaginal seal especially in mares with vestibular incompetence

Question 20

What causes urovaginum in mares

Answer 20

Cranial displacement of the vagina causing urine to pool in the cranial vaginal vault

Question 21

What are clinical signs of urovaginum

Answer 21

Constant urine dribbling vaginitis cervicitis urometra and urine scalding

Question 22

What is the typical treatment for persistent urovaginum

Answer 22

Urethral extension surgery to direct urine caudally and avoid contamination

Question 23

What is a persistent hymen and where is it seen

Answer 23

A retained membrane at the vaginal opening seen especially in maiden mares and can block exams or insemination

Question 24

How is a persistent hymen usually treated

Answer 24

Manually ruptured or sectioned with a guarded blade under aseptic conditions

Question 25

What is cervical incompetence and how does it impact fertility

Answer 25

It refers to a cervix that fails to open or close properly leading to fluid retention or infection

Question 26

What can cause cervical adhesions in mares

Answer 26

Repeated trauma or foalings which may require daily manual breakdown and can lead to pyometra

Question 27

What are endometrial cups and when do they form

Answer 27

Glandular structures that form around day 35 of pregnancy and secrete eCG even if pregnancy is lost

Question 28

Why can persistent endometrial cups impair fertility

Answer 28

Because they continue to secrete hormones and prevent return to normal cycling even after pregnancy loss

Question 29

What are intrauterine marbles used for in mares

Answer 29

To suppress oestrous behaviour by mimicking pregnancy though largely considered placebo

Question 30

What is the concern with endometrial cysts

Answer 30

They can interfere with embryo mobility and maternal recognition of pregnancy particularly if large or numerous

Question 31

How are endometrial cysts diagnosed

Answer 31

Transrectal ultrasound hysteroscopy and occasionally uterine biopsy if fertility is affected

Question 32

What is endometritis and how common is it in mares

Answer 32

Inflammation of the endometrium and one of the most common causes of infertility

Question 33

What is persistent mating induced endometritis

Answer 33

Failure to resolve post breeding inflammation within 24 to 36 hours leading to prolonged uterine reaction

Question 34

Which mares are more susceptible to PMIE

Answer 34

Older multiparous or conformationally poor mares that cannot clear inflammation effectively

Question 35

How is PMIE managed in breeding mares

Answer 35

Single insemination per cycle followed by uterine lavage oxytocin and intrauterine antibiotics

Question 36

What is endometrosis in mares

Answer 36

Chronic degenerative endometritis marked by glandular fibrosis and poor breeding prognosis

Question 37

What is pyometra in mares and how is it treated

Answer 37

Accumulation of pus in the uterus treated with repeated drainage lavage and culture guided antibiotics

Question 38

What is an anovulatory haemorrhagic follicle

Answer 38

A large non ovulating follicle filled with blood which may luteinise but does not release an oocyte

Question 39

How are anovulatory follicles treated in mares

Answer 39

Usually not treated as they resolve spontaneously but prostaglandin may be used to induce luteolysis

Question 40

What is a granulosa thecal cell tumour GTCT

Answer 40

A steroid producing ovarian tumour that causes abnormal behaviour and hormonal disruption

Question 41

What is a hallmark diagnostic sign of GTCT

Answer 41

Unilateral enlarged ovary with contralateral atrophy and elevated anti mullerian hormone

Question 42

What is the definitive treatment for GTCT

Answer 42

Surgical removal of the affected ovary via ovariectomy which is curative