Equine 2 Flashcards
When are most causes of fetal loss in the mare?
Nearly always in late pregnancy and therefore get abortion and expulsion.
Rarely get mummificaion in the mare.
Why do you get embryonic death in endometritis?
Presence of bacteria or inflammatory products within the uterus as a result of mating-induced endometritis creates a hostile uterine environment and prevents the mare from staying pregnant (when the conceptus enters the uterus on day 5/6)
If a mare is at risk of low progesterone during pregnancy when would be the most high risk period?
Before endometrial cups are formed, here they may benefit from supplemental progesterone
What are the most concerning causes of abortion in the mare?
Infectious prime concern
What are some of the non infectious causes of equine abortion?
Multiple conceptuses
Umbilical cord abnormalities
How many mares get twins?
10%
How can you plan examinations for twins?
Day 14 and if suspicion of twins then re-examine 2 days later
Day 21
Day 35
How can you deal with twins in the mare?
Abolish whole pregnancy with PG- likely to occur at next pregnancy
Manual rupture of one conceptus at day 14/15
What can occur to the umbilical cord in foals?
Torsion –> death
What are some infectious causes of fetal abortion?
Equine herpes virus
Equine viral arteritis
Bacterial/fungal placentitis
What herpes virus normally causes abortion?
EHV1
When do most abortions occur with EHV?
Most abortions within 60 days of infection but most are seen after 250 days
How is EHV spread?
Respiratory route
What is your approach to mare aborting due to EHV?
- Isolation of mare
- Advise that mares are kept in groups according to stage of pregnancy
- Isoalte new arrivals
- Control by vaccination of pregnant mares at 5,7, 9 months of pregnancy
How is EVA transmitted?
Resp tract and veneral
What are classic disease signs of EVA?
flu-like but with significant conjunctivitis, (pink eye) focal dermatitis, limb and ventral oedema
What occurs to EVA in a stallion?
may infect the accessory glands and result in a persistent infection
Do mares develop immunity to EVA?
Yes
What do aborted fetuses look like in EVA?
partially autolysed (unlike fresh foetuses seen with EHV) however still need appropriate pathological examination
How can you prevent EVA?
Screening mares prior to breeding Vaccinating stallions (require serology to be negative prior to vaccination)
What are some signs of bacterial/fungal placentitis?
Usually vulval discharge, mammary changes and then abortion
How can you diagnose placentitis?
Focal abnormality of cervical star
What is placentitis associated with?
Poor perineal conformation
What is the tx of bacterial/fungal placentitis?
culture/sensitivity but usually systemic potentiated sulphonamide and consideration of progesterone supplementation
What is the effect on the foal in placentitis?
Affect growth, foal may die
What is a red bag delivery?
The placenta has not ruptured at the cervical star during parturition
What is the most common method for shortening the luteal phase in the mare?
Prostaglandin administration between day 5-12 causes return to oestrus 4-6days later
What is the most common method for hastening ovulation?
GnRH agonist (deslorelin) or hCG
Plan breeding 24 hours after injection.
What are some common abnormalities of cyclicity in the mare?
Prolonged dioestrus
Erratic oestrus during transitional phase
Absent oestrus post-partum
Silent oestrus
What is the pathogenesis of prolonged dioestrus
Caused by persistence of secondary CL in absence of pregnancy
What is the incidence of prolonged disoestrus?
24% of cycles - common
What are the signs of a prolonged dioestrus?
Failure to return to oestrus
What is the treatment of a prolonged dioestrus?
PG single dose
How can you treat erratic oestrus during the transitional phase?
Providing 16hrs artifical light and additional nutrition from 1st December
Once mare in transitional period (follicles 2.5cm) progestogens (regumate) administered, this is withdrawn when follicles are 4.5cm (can also give GnRH agonist at this point)
What is lactational anoestrus?
Mares that foal early in the year and therefore should not be expected to return to cyclical activity
How can you treat lactational anoestrus?
There is no tx.
Increase nutrition and lighting and attempting to bring the mare into transitional phase and then using progestogens
What is foal shy?
Mare that are protective of the foal and although they have follicle development and ovulation they suppress behavioural signs
What is a silent oestrus?
A mare that will not show signs of oestrus or will not allow mating although other examination confirms that she is in oestrus and close to ovulation
When is silent oestrus usually seen in?
Maiden mares or mares with foal at foot
What are some conditions that could be mistaken for nymphomnia in the mare?
Persistent oestrus during transitional period
Mare that are difficult to handle during oestrus
Bad mares
Granulosa cell tumour
What are some reproductive clinical signs of a granulosa cell tumour?
If produce oestrogen = persistent oestrus
If produce progesterone = persistent anoestrus
If produce androgens = virilisation
Plasma inhibin concentrations may be elevated
They don’t produce nymphomania rather persistent oestrus