Equine 3 Flashcards
the attachment between the chorioallantois villi and the endometrium is diffuse except for where?
the cervical star
what is a mucus plug? when is it ideal to pass?
cervix produces a thick, viscous that helps prevent bacteria from passing up there!! ideal to pass right before foaling and can be mistaken for discharge!
if you see a mucus plug being passed early, like around month 8,9,10, what are you concerned about?
placentitis/infection gettin up there
why is placentitis (bacterial in origin) a problem?
it disrupts transfer of gasses, nutrients, and blood flow to the fetus
risk factors for ascending placentitis?
since the pathogens enter via the cervix:
- history of fetoplacental compromise
- poor vulvar conformation
- cervical dysfunction
- aged mare/immunocompromise
describe the pathophysiology of ascending placentitis
bacteria migrate through the cervix and cause infection at the cervical star. Infection then spreads thru the chorioallantois from the cervical star and causes necrotizing inflammation. requires failure of the mucus plug. some bacteria make mucolytic enzymes like pseudomonas, but others can be E coli, strep zoo, klebsiella, etc. The inflammation causes PGF2 causing contractions and if bad enough can cause abortion
you go see a horse named Lizzie and shes 8 months pregnant. she has premature lactation and udder development and also has some vaginal discharge. #1 differential?
placentitis
you think Lizzie has placentitis. How will you diagnose her? there are a lot of things you can do….
always use your clinical signs and use an ultrasound–>measure combined thickness of the uterus and the placenta at the cervical placental junction. You will also see fluid accumulation behind the chorioallantois.
can also do a vaginal speculum exam, but be careful not to disrupt the mucus plug, don’t force it! if you mess with the cervix too much you can induce contractions.
can also use fetal HR–>typical for 6 months gestation is 120-130, with placentitis it is increased usually
plasma progesterone levels: high levels indicate fetal stress
Lizzie showed a thick uterine/placenta with fluid behind the chorioallantois, and baby’s HR was 150 (elevated). How will you treat her?
antibiotics–>TMS or penicillin
antiinflammatories–>flunixin or phenylbutazone
progesterone therapy–>regumate/altrenogest to support the pregnancy
Pentoxyphlline–>improves blood flow to placenta, reduces viscosity
you get a farm call about Stella; a mare that is pregnant. she has a rapidly enlarging abdomen and the contour of her ventral abdomen has changed acutely. she also seems to have painful edema ventrally. Thoughts? How will you treat her?
YIKES I’m thinking rupture of the abdominal musculature or a rupture of the prepubic tendon. you can’t fix this; most you can do is pain control and reduce movement. Many times this ends in euthanasia. could also try an abdominal bandage
clinical signs, diagnosis, and treatment of uterine torsion?
CS: low grade colic that is not responsive to medical treatment
diagnosis: rectal palp–>you’ll feel a sheet of broad ligament that extends across the caudal abdomen–>pathognomic!
treatment: surgical or roll them
why should you use caution when using antispasmodics with a pregnant mare?
can cause cervical relaxation
describe what premature placental separation is
when there is separation of the chorioallantois from the endometrium without rupture of the amniotic sac–>result is the fetus has no blood supply
when should a horse pass fetal membranes?
within 3 hours of birth
why do we advice the owner to tie up the placental tissue to keep it in tact until it is passed. why?
dont want the mare stepping on it and tearing/pulling on it, it can lead to tears or hemorrhage
it is important to keep the placenta in tact and do a thorough exam. why? what part of the placenta are we most worried about and why?
we can see if any of it is missing and maybe retained/still inside
tip of the non gravid horn–>part that is typically retained
why is retained fetal membranes urgent?
it can lead to metritis, septicemia, endotoxemia, lamanitis, and death
what are our treatment goals for retained fetal membranes?
remove the membranes, dilute inflammatory mediators from the uterus, control any systemic inflammation, reduce the risk of lamanitis
can you remove retained fetal membranes manually?
controversial! if you do it, go slow and steady, dont tear it, and work with the uterine contractions! if you’re too aggressive it can cause hemorrhage, endometrial damage, etc.
describe how to treat retained fetal membranes medically
sedate them and load them into stocks, use oxytocin to get them to contract, float the placenta (fill it with water to stim uterine contractions), calcium IV fluids, +/- manual traction
attempt 1: oxytocin and weight on placenta
attempt 2: oxytocin, float the placenta, IV fluids with calcium
attempt 3: manual traction
what are the 3 Ps of dystocia?
preserve the life of the dam, the life of the fetus, and the dam’s future fertility
if you do a C section in a mare, what do you lose?
the mare :( she will die in the field
consequences of uterine tear
colic signs and peritonitis
you’re going to see Ruby, a 15 yo mare that’s had many foals before. She had an acute onset of colic signs, she is anxious, painful, sweating, has pale mms, and is tachycardic. Differential?
uterine artery rupture (hemorrhage into the broad ligament), diagnosed on rectal palp
hemorrhage into the abdomen is usually more low grade colic signs but can rapidly progress to hypovolemic shock, diagnosed on uktrasound
when are mares prone to colon torsion?
first 3 months post foaling and we arent sure why, something to do with the microbiome?
