Leah Patton, from ADMS Brayer journal Jul/Aug 1997, Vol 30 #4, author unstated


We had a call here at the ADMS office from a man who had a dilemma.  He knew of two good mares, both bred to the same good jack, who had both lost their mule foals.  One mare had lost a six weeks premature foal two weeks earlier.  The second mare delivered a stillborn foal on the morning that he called.  Having lost the entire foal crop for that year for that breeder, he needed some advice on what could have been the cause of such a disaster.

We are not vets at the office, and we recommend calling your vet first, or we can have your vet consult with our vets.  But we can offer some basic suggestions so you can get an idea of what needs to be done and what direction to start.

First, a post mortem should be performed on the stillborn foal to rule out internal abnormalities, such as heart or circulatory system defects.  Unless a post mortem is performed, these internal defects would never be detected.

If nothing shows up clearly in the post mortem then you can begin to consider other factors.  Was the labor unusually hard or prolonged?  Was the foal in a normal presentation or was it breech, or otherwise abnormally presented?  Dystocia-- abnormal birth presentation, such as having the head or legs back-- can often result in a stillbirth.  Stress, caused by any number of situations from a new environment to a bad storm, could be a factor (and is more common in wild herds with heavy predator influence) in the miscarriage of a foal and should not be overruled if no other cause can be found.  Familiarity with the mare's background and behavior will help in the knowledge if she had suffered excessive stress.

It is possible for mares to be incompatible in blood type with their foals, just as the RH factor plays a role in human pregnancy.  However, the odds against two mares bred to the same jack both being incompatible are slim, unless the mares were full sisters.  A simple blood test on the stud and mare can see if this was a possibility.

A uterine biopsy on the mares can determine if the mare had a uterine infection.  Not only can untreated infection (uterine or urinary tract) cause abortion, but it can also lead to permanent scarring of the mare's reproductive system, eliminating the mare from a future breeding program and possibly leave her sterile.  Sometimes the jack or stallion can be a carrier of the infection, even though he shows no outward symptoms himself.

Making sure that mares are washed, and that the jack is cleaned before each service, or the use of Artificial Insemination (AI) can help eliminate the spread of infection, especially on studs that service outside females.

If no clear cut cause has been determined by this point, then other possibilities might be explored.  Time, effort, and money may be involved, but for a breeder that has lost a year's investment, you would not want a possible repeat the following season.  Certainly you would want to make sure that the mare was healthy and sound before rebreeding her for the next year.

Diet is another consideration.  There are poisonous weeds and plants, that if consumed in quantity could cause fetal death and abortion (such as fescue, or the ergot mold on rye).  Lack of certain nutrients, or the abundance of toxic ones, could cause fetal deformity.  Know what poisonaous plants are in your area, and feed only good pasture and good quality hay free of weeds and especially free of mold.

Mares that foal unobserved in the pasture may reject the foal, or it might not be able to free itself from the birth sack.  Exposure has claimed many a small weak foal, from maiden and experienced mares alike.

Equine twins are often casualties as well.  Unlike other animals with twins, the second twin must be delivered quickly or it will breathe before it has been fully delivered and will drown in the birth fluids.  If the mare bonds with the first foal and rejects the second, it could be trapped in the amniotic sack, or die of exposure.  In most twin births, the twins are of different sizes, and the smaller twin has a severe disadvantage.  Many twin pregnancies end in the loss of one or both twins.  Singleton foals can also survive while the second twin is reabsorbed or stops growing partway through the pregnancy.

Lethal White Syndrome, common in Paint horses, and linked apparently to the Overo spotted pattern, has not yet been documented in donkeys or mules.  The Roan gene in horses is also lethal in a homozygous (RR) dose, but as color studies are still under research, we do not know if color of the foal (such as albino white or highly spotted) could have a link to miscarriage and stillbirth in longears.

Studies in humans have shown that one of every eight pregnancies is miscarried naturally before it is ever realized that the pregnancy has occurred.  In horses, the conception rate is somewhere around 60%, with about 60% of these pregnancies coming to live birth.  Given these figures, it is a miracle indeed that a positive number is ever seen in the birth rate.

In short, there are a great number of causes that could be responsible for the loss of a fetus.  Having your vet perform a post mortem first can eliminate some of the guesswork, and allow you to make changes in the situations that led to the problem in the first place-- be it a different jack, new location, different diet or other situation.

For an article on Fescue problems, contact the ADMS Hee Haw Book Service and ask for article #50.  Your local Agricultural Extension Agent can also help you with a guide to poisonous plants in your local area. 
Home (Index)

About donkeys

About Mules


Zebra Hybrids

Mule Pix

Calendar of Events

The BRAYER (membership Magazine)

Membership Form (Dues)****

(external secure link)
Renewing members Short Form
(external Secure Link)

About ADMS


FAQ (frequently asked Questions/Trivia)
Includes info on FERTILE MULES, twins, speed of mules/donkeys, etc

Breeding Questions

About Jacks

VHOF (Versitility Hall of Fame)

Lingo (Terminology)

Diseases in Longears


What Can you Do w/Longears?

Clubs and Organizations

Books ( Our "Hee Haw Book Service")

Member Photos

Links (Breeders and Farms)

Measuring Equines

Tail-less Donkeys?

On Gelding (Castration)

Buyers Checklist (BEFORE you purchase!)

SPOTTING PIX (pinto-spotted donkeys)

Dear John Henry (advise from a Mule)


One tough Mule/Bad-ass Mule

New info - Medical/Shots/Worming

FEES for ADMS Services

Microchipping Notice Sheet
(to inform ADMS of added chip #s for your animals)  New 6-6-08

Found a lost or strayed Longear with a Microchip?

Need literature?
Visit  Hee Haw Books


Measuring for Dwarfism in Donkeys

Registered Farm Names
   F-J     K-O   P-S   T-Z
Farm names End 06    Feb-June 07
July-Dec 2007      SEE NOTE RE UPDATES

Prefixes MAIN
(Farm names added 8-20/21-08)
Prefix/Name Rules (see Rules)
Registration Info
Where Does my Donkey Go?

Registration Form   or NEW PDF VERSION

Secure Online form Miniature/MDR Only

Secure ONLINE FORM for all other Longears

PLEASE READ HERE before using online form
(* Since we now have online forms, we will no longer assign numbers for show. * )
Registration Rules 1

Registration Rules 2

Registry Checklist

Inspection Form

Transfer Form or   NEW PDF Version

Update Form      or  NEW PDF Version

Stud Report

Breeding Certificate
(on the reg form)

Stud Contract

Sales Contract

Code of Ethics (PDF)

REGISTRY changes 2009

Permanent ID OPTIONS 2010
The ONLINE Registration form is up and running! Please use it for new registrations of donkeys or mules of all sizes.   Link is above.


VHOF/Versatility Hall of Fame