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  Discussion on Multiple foal deaths at birth - help!
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Member:
mleeb

Posted on Wednesday, May 14, 2008 - 8:00 pm:

A friend of mine has had 11 mares foal in the last 3 weeks, and has only 3 live foals to show for it. Needless to say, she's tearing her hair out with the stress of it all, and she still has 30 more mares to go. Here's the history:
Lori, the friend, bought a brood mare band from a long time family friend who is quite elderly and wanted his herd to go somewhere where his 40+ years of breeding would continue on. The mares, all bred, began arriving late last fall, and I believe they were all moved by January. It was a 2 hour drive. They are all papered QH mares, various ages, and all in good health.
Three weeks ago, the first mare foaled in the wee hours of the morning. It was dead when the herd was checked around breakfast time. Two days later, another one was found dead, this one partially consumed by the coyotes. The herd was immediately moved closer to the house where they would be in plain sight. Their pasture is next to a gravel road with a fair bit of traffic now that it is planting season. A third foal was then born, this one survived. It was born to a mare my friend had owned for years. (I should mention that she is not new to breeding, just new to having quite this many mares.)
Over the last 10 days, 8 more mares have foaled, for a total of 11 mares. There are only 3 surviving foals. The most recent foal to die was today.
So, a little more history for you:
1. The former owner did not vacinate for Rhino, a recently discovered piece of information.
2. Four to six weeks ago, the herd was dewormed using Safeguard pelleted dewormer, given to them by their local vet who assured them that it was perfectly safe for pregnant mares. After it was fed, they noticed the bag was labelled for cattle, not horses.
3. Of the 3 births they have witnessed first-hand, all the foals were born live, and died within a few minutes. All were still attached to the placenta. Today's foal was still encased in it's bag, which was so thick and strong it required a knife and a fair bit of effort to cut it open.
4. The two dead foals from 3 days ago were picked up by a different vet from a neighboring town who performed a postmortem on one and found nothing of relevance, and sent the second to the University of Saskatchewan (which has a veterinary division) for testing. No results have come back as of yet.
So, the first questions they have are is this from the dewormer, or maybe from Rhino? Is the location of the pasture causing a problem? Are there any preventative measures that can be taken to prevent the rest of the foals from dying as well?
Any ideas at all would be welcomed.
Member:
morg1

Posted on Wednesday, May 14, 2008 - 9:16 pm:

Oh, how sad and so frustrating for the owner. I really don't know. All of the things you mentioned makes me wonder, but could the mares be on fescue pasture? I will definitely be watching to see what DrO says.
Moderator:
DrO

Posted on Thursday, May 15, 2008 - 8:08 am:

Hello Michelle,
Do to an inability to deal first hand with the issue time and time limitations, we do not normally respond to requests for help with horses not directly in your care. However this is pretty bad and I know the owners must be greatly concerned. There is nothing in your post that suggests the cause of the problem so treatment is highly speculative. The fact the foals looked normal to the veterinarian does rule out some important diseases. What needs to happen is the foals that have died needed to have a necropsy done so that the cause of death can be determined and from there possibly a treatment plan can be developed. The history certainly suggests a nutritional, infectious, or toxic factor but what that factor might be is not evident from your post. Hypothyroidism in foals has been reported in the Saskatchewan area causing epidemic foal death. For more and other potential rule outs see Diseases of Horses » Endocrine System » Hypothyroidism in Foals.

For a list of other possible problems you might look at Diseases of Horses » Reproductive Diseases » Problems During Pregnancy and Diseases of Horses » Foal Diseases.
DrO
Member:
christel

Posted on Thursday, May 15, 2008 - 9:10 am:

Michelle, how sad this is for all involved. When you mentioned that one foal had to be 'cut' out of the bag, my first thought was fescue grass. Have the mares been on this type grass? Fescue grass can have a fungus that will cause the bag to be hard for a foal to get out of when born, and they will suffocate.
Hope you all find some answers soon.
Member:
kathleen

Posted on Thursday, May 15, 2008 - 10:12 am:

Michelle,
I had a friend who lost almost every foal one year. It was similar to what you posted, including that most of them were born alive and died later. Some of them had eye problems just before they died. They tested everything possible to find out what was happening. If I remember correctly, they have a pond in the pasture (no fescue) that was tested and something was found that they believe was causing the problem. They had to treat the pond, don't remember with what, but it solved the problem. It was about 8 or 9 years ago so I don't remember enough about it to give details. Hope this helps. It is just heartbreaking to see (and hear) about these poor foals and the mares and the owners.
Member:
aannk

Posted on Thursday, May 15, 2008 - 4:35 pm:

Could it possibly be MRLS?
Member:
mleeb

Posted on Thursday, May 15, 2008 - 4:57 pm:

I'm not familiar with that one. What's MRLS?

I talked with Lori this morning and read her all of your posts. She's very grateful for your input, and expects to hear back on the autopsy report later today. I'll post the results. She wrote down all the possibilities mentioned above, and plans to ask her vet about them.
Member:
erika

Posted on Friday, May 16, 2008 - 8:45 am:

Alicia, I was wondering the same thing...MRLS, Michelle, stands for Mare Reproductive Loss SynDrOme I believe. It was an epidemic of foal loss in Kentucky among racehorse breeders that was in the news a few years ago. If I remember correctly, it is from the feces of Eastern tent caterpillars that ate wild cherry leaves.

Manitoba is a plains province though, isn't it? Any wild cherry trees?

This is so sad...I hope they find the reason and are able to do something about it. It must be heartbreaking to watch foal after foal die!
Erika
Member:
mleeb

Posted on Friday, May 16, 2008 - 9:21 am:

Ahh, ok. I was reading about that a few days ago.

Manitoba IS a plains province, that's correct. However, the northern 2/3 are forest and rock. Where I am is just on the edge of both. My friend is actually 2 hours north west of me in Saskatchewan.

I imagine there are wild cherry trees - do pincherries count? They're quite common. No idea if the tent caterpillars are found in the area, though.

I believe the mares are going to be moved to a new pasture tomorrow, once the cows are moved off of it. They are just going to open the gate and let them drift there on their own so there's no stress. Another mare was foaling yesterday afternoon, no word yet on the outcome, or any response from the U of Saskatchewan on their autopsy.
Member:
aannk

Posted on Friday, May 16, 2008 - 12:44 pm:

Yes, Mare Reproductive Loss SynDrOme. I don't think tent caterpillars only eat cherry trees, though. I would check to see if they are in the area.
Alicia
Member:
erika

Posted on Friday, May 16, 2008 - 1:15 pm:

Right, they eat lots of trees but for some reason the ones that dined on cherry were causing the problems. Cherry trees are poisonous to horses, so maybe whatever is in the leaves is DrOpped onto the grass by the caterpillar DrOppings?

Perhaps if you do a search on it, Michelle, you will find out if it's a possibility in your area.
Good luck,
Erika
Member:
erika

Posted on Friday, May 16, 2008 - 1:36 pm:

Ooops! I stand corrected...after taking my own advice and Googling MRLS, I see that it is the caterpillars themselves that do the damage. Not necessarily what they are eating.

Evidently, horses will readily eat them (as shown on the very weird videos on the U of KY website!), and the hairs on the caterpillars injure the lining of the intestines. It makes them more vulnerable to germs and other things that shouldn't pass the intestinal lining.

Kind of similar to our gypsy moth rash locally. Ticks, stinging caterpillars,...I think I'm noving to the desert....
Erika
Member:
mleeb

Posted on Friday, May 16, 2008 - 7:46 pm:

Well, it appears that tent caterpillars are common in Saskatchewan, and many cities even spray for them. Any time I search for something that links them to Saskatchewan foal deaths, I get the Kentucky ones instead, but really the location hardly matters. Considering how completely cold and crappy our spring has been here - no rain, nights with below zero temps, days hardly any better (until 7 days ago when it suddenly got warm! Yippeeee!) - I would wonder how a live caterpillar could be found anywhere and consumed in sufficient quantities to cause this problem. The flies and mosquitos haven't even appeared yet!

Btw, before you move to the desert, think of the big spiders and the scorpions... ;-)
Member:
aannk

Posted on Friday, May 16, 2008 - 11:51 pm:

do they have to eat them now? what about if they ate them shortly after becoming pregnant?
not that i want to eliminate hope, but if this is the cause, it isn't her fault.
Moderator:
DrO

Posted on Saturday, May 17, 2008 - 5:32 pm:

Alicia, how much time might pass between exposure and problems is not known but in one study 100% of the horses exposed to whole caterpillars aborted between 3 and 4 days postexposure. For more on this see, Diseases of Horses » Reproductive Diseases » Problems During Pregnancy » Mare Reproductive Loss SynDrOme » Causes of MRLS: Experiment 4.
DrO
Member:
mleeb

Posted on Friday, May 23, 2008 - 6:18 pm:

Quick update: The vet tech was out to the farm this past week and was taken out to see all the mares whose foals had died (they are pastured separately). Lori felt that they appeared to be retaining water, but that they were improving now that they had the opportunity to pick at the new grass, although they are still mostly on hay. The vet tech agreed, and she was of the opinion that it was hypothyroidism induced.

Lori now has 6 live foals, hasn't lost one in about a week.

Today the vet at U of Sask left a very short message on her answering machine, stating that the autopsy revealed herpes. She has no more information than that as of yet, because when she called back the vet was in surgery, and she couldn't reach him.

That's as much as we know right now.
Moderator:
DrO

Posted on Saturday, May 24, 2008 - 9:59 pm:

Thanks for the update Michelle, let us know if there are any more information.
DrO
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