Horses are part of an ever growing industry, with over 600,000 horses in the UK, 1.4 million riders and 5 million people with an active interest in the equine industry*. Most people acquire a horse out of choice, so if you make this decision you should think carefully before going ahead. A horse needs lots of love and care, including regular worming, vaccinations and dental care. Owning a horse is time consuming and can be costly; not only will you will need to consider where you will keep your horse, you must also consider the ongoing costs of owning a horse which include accommodation, bedding, feed and healthcare.

In the unlikely event that your horse goes missing it is going to be very difficult for anyone to know who it belongs to, unless your horse carries some form of permanent identification. It is wise to get your horse microchipped or freezemarked, this will avoid heartache in the long run, should your horse go missing or is stolen.

Horses are herd animals, and thrive on being together with other horses. Don’t forget that your horse will need somewhere to graze, a stable for warmth in the winter time, a constant supply of water, feeding daily and regular exercise. It can cost hundreds of pounds a month to care for a horse, including accommodation, food, veterinary care and insurance; there will be other costs, including buying tack and rugs and extra livery charges when you go on holiday.

Horses can live into their thirties, over this time your horse will need lots of care and attention. Being able to provide all of this will ensure you and your horse make the most of your time together.

* Research conducted in 2004 by the Henley Centre for DEFRA and the British Horse Industry Confederation.

Preparing your mare for breeding (USA)

There are many factors to consider before you breed your mare. It is important to consider the costs, time and expertise required to breed a mare, and look after a foal.

Where do I start if I want to breed from my mare?

  • Decide whether you are happy for your mare to go away to stud or whether you would prefer to keep her at home for breeding.
  • Think about what stallion you would like to use, his fertility and what type of semen is available.
  • Find out if there are any periods over the breeding season when the stallion is not available.
  • Think about whether you would like the mare mated naturally or whether artificial insemination is more appropriate.
  • If artificial insemination is elected, determine the number of breedings you get in a season for cooled semen, or the number of straws and doses for frozen semen.
  • Think about where you would like the mare to foal, are you prepared to do foaling checks through the night yourself? Or would you prefer her to foal at a dedicated farm?
  • Ensure that you have the funds available to cover the stud fees, breeding management and foal expenses and that you are financially prepared for complications.

Why do I need to get my mare examined by a veterinarian?

It is important to ascertain that your mare is a good candidate to breed, with a normal and healthy reproductive tract. Knowledge of where the mare is in her estrous cycle and following her while in heat will increase her reproductive efficiency. Fertility declines with age, so horses over 13 years of age who have not had a foal previously or mares that have had many foals, may find it more difficult to conceive. It is also important to check for infectious and sexually transmitted diseases. Whether you are having your mare bred naturally or via artificial insemination it is important to time the breeding accurately, close to ovulation, in order to increase the chances of conception and decrease the costs involved.

What does a pre-breeding exam include?

Clinical exam

It is important to check that the mare is in good physical health. A lot of brood mares have orthopedic disease that prevent them being ridden. It is essential to ensure that the orthopedic problem is not likely to get significantly worse as the mare gets heavier in foal. A severely lame and painful pregnant mare is a welfare issue and the stress of orthopedic pain may result in abortion. Any systemic medical issues such as Cushing's disease, insulin resistance should be addressed. Brood mares should be the correct weight with a body condition score of 5-7 out of 10; a mare that is either too fat or too thin will struggle to conceive.

Vulvar exam

One of the most important parts of the reproductive tract that is frequently overlooked is vulvar conformation. The vulva, along with the vestibulo-vaginal sphincter (hymen) and the cervix form the three barriers of the uterus that prevent contamination from air and feces. The vulva should be vertical with the anus above it. In some older mares the anus becomes sunken and the vulva forms a shelf underneath - this is poor vulvar confirmation and makes uterine infection and inflammation more likely, reducing the chances of the mare to conceive.

Vaginal exam

It is necessary to examine the cervix and vaginal walls; this is done by placing a speculum into the vagina. Observing the cervix visually allows determination of where the mare is in her estrous cycle, as well as if signs of inflammation (redness), infection (discharge) or if pooling urine is present. It is important to check the cervix for scarring which can result in difficulty dilating which can lead to fluid being trapped within the uterus as well as potential complications at foaling. The ability of the cervix to close completely without any defects is also necessary. If the cervix doesn't close properly it allows contamination of the uterus potentially leading to chronic infection and inflammation. When checking for cervix competency, it is important to do so manually when the mare is not in heat, so that the tubular canal can be felt completely.

Rectal exam and ultrasound

Mares are long day breeders and therefore their natural breeding season is in the spring and summer. Artificial lighting with or without medical treatment can help advance their return to reproductive activity. Rectal palpation and ultrasound allow the ovaries, uterus and cervix to be evaluated anatomically and functionally. Ultrasound gives the ability to see things within the reproductive tract which can't always be felt. Ovarian structures (follicles, corpus luteum, etc), uterine edema, intra-uterine fluid, and endometrial cysts are all important to note during the examination. Putting the whole reproductive exam together can provide you with the knowledge of whether your mare has a normal reproductive tract and cycle which aids in preparing her for breeding, as well as providing her with the best chance for conception.

Blood tests and vaccinations

Equine Infectious Anemia (EIA) is an infectious disease that can be tested for easily using the Coggins test. It is required that all mares are tested prior to movement within and between states within the United States. This test should be performed according to state requirements and updated prior to breeding.

Equine Viral Arteritis (EVA) is a sexually transmitted infection; it can cause abortion, and can cause flu like symptoms. Mares should be tested if exposed to infected mares or prior to breeding if they are to be bred to a positive stallion. If they are negative and are to be bred to a positive stallion then vaccination is recommended prior to breeding. If the mare is positive, then exposure to positive semen should not affect the mare. Any time a mare is bred to a positive stallion she should be isolated so that other mares are not exposed by shedding.

Clitoral swabs

Clitoral cultures are usually performed if mares have chronic uterine bacterial or fungal infections since it is a warm, dark environment in which for them to grow. Contagious Equine Metritis (CEM), a sexually transmitted disease, is not endemic in the USA, therefore clitoral cultures prior to the breeding season are not routinely required, however mares that have been imported into the United States from CEM countries do have to undergo CEM testing following a specific protocol. In addition, any mares potentially exhibiting signs, or potentially exposed, should be cultured.

Uterine culture and cytology

Uterine culture and cytology are important in identifying infection and inflammation. A culture provides evidence that bacteria, fungal or yeast infections are present. Cytology helps determine if inflammatory cells are present, in addition to bacteria, fungus, yeast, debris and mucous. A mare can have endometritis (inflammation of the uterus) with or without infection. It is important to identify inflammation since causes of inflammation alone can decrease a mare's ability to conceive. Whether a culture or cytology is required prior to breeding, is determined by the stud/farm requirements, stallion contracts, and most importantly by the mare - if she has a poor reproductive history, any evidence of abnormalities on reproductive examination, or problems foaling, then these procedures are highly recommended.

Uterine biopsy

Uterine biopsies aid in determining the underlying health of the uterus. It provides information with respect to what problems need to be addressed and the probability of the mare carrying the pregnancy to term. Endometrial biopsies are recommended for mares that have a poor reproductive history or a history of fetal loss or abortion.

What can be done if my veterinarian finds a problem at the pre-breeding exam?

Many problems can be resolved, for example:

  • If the mare is too fat or too thin this can be addressed prior to service.
  • Vulvar confirmation can be improved by means of a Caslick operation - this is where part of the vulva is stitched shut to improve the vulvar seal and reduce the risk of contamination from fecal material.  
  • Abnormal cycling can be resolved by using different hormonal drug therapies - these are given to the mare to induce normal cycling. 
  • Mares that have intra-uterine infections can be treated with appropriate antibiotics.
  • If abnormal fluid is seen within the uterus, treatment can be initiated once the cause has been identified.

How should my mare be prepared for mating?

Once your mare has undergone her pre-breeding reproductive exam, and any recognized problems have been addressed, she can be prepared for breeding.

The chances of her conceiving are higher if mating is timed to coincide with ovulation. It is a good idea to keep a record of when your mare is in heat, as this will help your veterinarian determine whether she is cycling normally. Palpating and ultrasounding her ovaries, uterus and cervix will enable your veterinarian to track follicle development and uterine edema with cervical softening, to help predict when she will ovulate. Once ovulation is imminent the mare can either be taken to the stallion or the semen can be ordered. It is important to know how long in advance stallion managers need notification for semen to be shipped. In addition, making sure frozen semen is accessible when needed is imperative. It may be necessary to examine the mare twice or even three times daily prior to ovulation if frozen semen is used.

When do I find out if my mare is pregnant?

It is possible to detect a pregnancy using ultrasonography as early as 11 days after ovulation. Most veterinarians recommend ultrasound examination at 14 or 15 days post-ovulation, during the stage when embryos are still able to move. This allows identification and resolution of twin pregnancies if they are present.

It is recommended to have your mare ultrasound again between day 28-30 and day 42-45 to check for a heartbeat and to assess fetal viability. Unfortunately, if the mare loses the pregnancy after day 40 it is highly unlikely that she will cycle again normally and therefore will not be able to be bred again that season.

Fetal sex determination can be performed between 58-70 and 110-120 days if desired.

Gestational length is incredibly variable in the mare ranging, on average, from 320-340 days.