After False Pregnancy

[SILVER]

What shot is used to bring a mare to cycle after false pregnancy.

 

[Nathan Luszcz]

Mares don't technically have false pregnancies. You need to figure out why she showed signs of pregnancy, why she lost it if there was one, and what is keeping her from coming back in to heat. There are several things that show signs similar to pregnancy and each one is treated differently.

The shot you may be thinking of which aborts young fetuses, short cycles mares you missed, and brings mares that are cycling back into heat is called "prostoglandin f2-alpha", two trade names for which are "Estramate" (synthetic), and "Lutalyse" (natural, but nasty side effects).

There are so many hormonal drugs used for different reasons the one you may be thinking of might be one of many others.

 

[Becky]

In addition to what Nathan said, you would want to have your vet ultrasound your mare to determine exactly what is going on. We also have had good luck putting a mare on 10 days of Regumate to get them cylcing again.

 

[Nathan Luszcz]

Unfortinately Regumate isn't responcible for starting your mare cycling. All Regumate is is a synthetic progresterone, which mimics the second half of a mare's cycle. Perhaps your vet was trying to synchronize her?

 

[SILVER]

Thank you so much for the responses. The name I was trying to think of was the Estrumate. I have been to the vet this afternoon and he is booked to come out next week to further investigate things. I have a mare that isn't cycling and one that seems to be a real hussy that won't settle. Always something it seems. Thanks again for the responses.

 

[Joyce]

I had two mares one year with false pregnancies and the Vet came and gave them a shot to shock their system back to normal so they wouldn't go into labor but I don't remember what the shot was. I will have to look in my records and see if I can find it.

I know of one farm in NY state that had a false prenancy, mare went into labor, and of course delivered nothing and if I remember correctly they lost the mare thru the process.

 

[Becky]

Nathan, my vet was here a few weeks ago to ultrasound some mares. One hasn't been cycling all season. He checked her and said she was shut down and go with the 10 days of Regumate to see if we could get her going again.

 

[Nathan Luszcz]

I wonder what he's trying to accomplish. Progesterone would make her think she's pregnant, not push a new wave of follicles. Seems like a waste of money to me. And you said it worked?

It is extremely rare for a mare to go into labor without actually having a foal or the remains of a foal. Mares do not have false pregnancies. On rare occasion they will bag up for no apparent reason (even yearlings) and look like they may foal, but its not a reproduction issue, generally its a hormonal hiccup. There is no shot to "shock" their system into not foaling. PGF 2a will destroy a CL and (if the mare is cycling) bring her back into heat. Regumate will prolong a mare's diestrus, or help keep a foal if the mare's CL is not producing enough. Oxytocin will cause a late term mare to go into labor, and will also squeeze the uterous. Estrogen, FSH, GnRH, etc will affect a mare's cycle but not a pregnancy. There isn't many other shots one can give, reproductively!

The biggest thing that is called a false pregnancy is when a foal is lost after 50 days or so. At that point the fetus has ceased to be an independant embryo and has begun to "implant" (mares don't implant like woman do) into the mare's uterous. Once that happens, even if a fetus is lost, the mare's body won't cycle again until the beginings of the placenta are removed and the uterous "reset". That may take a few weeks, months, or even an entire season. (one of the reasons twin checks are so important)