Infertility workshops Flashcards
What does BAR DUDE stand for
Bright
Alert
Responsive
Defecating
urinating
Drinking
Eating
What do you see in a mares ovary immediately after ovulation
corpus haemorrhagicum- large blood filled structure
Large anechoic structure
What does free fluid in the body of the uterus indicate
always abnormal unless immediately after mating-> may suggest endometritis
What happens to vulval confirmation when a horse looses muscle and fat
anus becomes sunken
Faecal contamination of vestibule and ascending infection into the uterus more likely
Mare is more likely to loose a pregnancy if she gets pregnant
What is the most common cause of infertility in the mare and what factors predispose to this
Post-breeding or breeding/ mating induced endometritis
Increased bacterial load or reduced drainage (due to poor uterine contractions, abnormal cervix, dependant uterus)
How to treat/reduce risk of post-breeding endometritis
Early treatment (removal of fluid post mating, use of antimicrobials) may allow the mare to get pregnant
Surgery to improve poor conformation reduces the risk of the problem
When does the natural and thoroughbred breeding seasons start
Natural- April-July
Thoroughbred- February (11 month gestation, age of foals counted from 1st Jan so want them to be born as close to but after then
Why are pregnant mares also put in artificial light
when they foal they think it is already spring time and start cycling again straight away
Why might exogenous progesterone be given to a mare
Exogenous progestogens (altrenogest [Regumate]) causes suppression, storage of gonadotrophins and surge release when stop progestogen
Used as method of inducing/synchronising oestrus by administration and withdrawal of the product
when its given it negatively feeds back to the hypothalamus but when it is withdrawn there is a big surge of GnRh from hypothalamus which can help a mare to reach high levels of FSH adn LH needed to ovulate
Why wouldn’t you give exogenous progesterone to a mare in anoestrus
There is no GnRH to suppress with the progesterone in the first place -> they just need light
Why are mares put under artificla light
The imposed breeding season and the natural breeding season do not coincide at least for thoroughbreds (we often try to breed when mares should not be expected to be cycling)
Supplementary light can advance the transitional phase, and then suppression with progestogens and their subsequent removal may allow onset of an ovulatory cycle
Additional drugs may be required to force ovulation after progestogen withdrawal
What is dioestrus ovulation and why does it occur in mares
Normally in the luteal phase waves of follicles grow but regress due to high levels of progesterone
Sometimes the luteal phase follicle ovulates – this seems strange because the oocyte is released at a time when progesterone is high and the mare is not in oestrus. These are called dioestrus ovulations and they result in the formation of a new CL
The mare still produces PG from her uterus at the normal time (day 16) and this PG lyses the first (primary CL) as expected
If the new CL is young when the PG is released it may not be lysed (remember CLs are resistant to PG for the first 5d)
There is no new production of PG so the new CL persists
How common is a dioestrus ovulation in the mare and what does it result in and what is the treatment
Common- around 24% of cycles
Results in prolonged dioestrus
Treatment is a single does of PG
What is the most common cyclic abnormality in the mare
Prolonged dioestrus- persistence of a secondary CL, which is the result of a dioestrus ovulation
What is a granulosal cell tumour
Most common ovarian tumour in the mare
They can affect mares of many ages
They are usually endocrinologically active, so often the contra-lateral ovary is supressed and is small
Many are asymptomatic and are incidental findings (possibly in the early course of the disease)
They may secrete
Oestrogen – resulting in persistent oestrus
Progesterone – resulting in failure to cycle
Androgen – resulting in virilisation
