Ask The Vet: Equine Reproduction - January 07

Pregnancy toxemia doesn't exist in the horse. Pregnancy toxemia in humans is associated with hypertension and the associated problems. Pregnancy toxemia in sheep and goats is related to plane of nutriton and production of ketones. The stress of pregnancy can potentially be enough to produce an HYPP attack, but I would think that the mare would have shown other problems with HYPP prior to "just up and dying."

We will typically examine the mare's external conformation first. Is the vulva straight up and down or is it tilted? How much of the vulva is above the brim of the pelvis? This helps decide the risk of contamination of the vagina and of aspiration of air into the vagina. Next we will palpate and ultrasound the mare's reproductive tract. Are there two ovaries present and are they normal in size and texture? Are there follicles and or a corpus luteum present? Where is the uterus located in the abdomen? In a normal mare, the uterus will be high in the abdomen at the level of the brim of the pelvis. Older mares and mares that have had multiple foals may have a pendulous uterus that sits low in the abdomen. Is there edema present in the uterus? If the mare is in heat, there should be. If she is out of heat, there should not be. Is there free fluid in the uterus? There should not be any free fluid present. We will then perform a vaginal speculum examination to evaluate the vagina and cervix. If we see any abnormalities or suspicious areas, we will perform a manual examination of the cervix.

The biggest problem you will most likely face with a 12-year-old maiden mare will be a cervix that does not relax properly. In most cases, this can be dealt with using misoprostol or cloprostenol to aid in cervical relaxation and uterine lavage to help remove inflammatory byproducts. We usually do not perform a uterine biopsy on maiden mares unless we see something during our examination that indicates it may be needed. If this is desired, it must be discussed with the seller. Good luck with your potential purchase.

The size of the foal is limited by the size of the uterus. In the horse, the type of placentation present will generally limit the size the foal at term. This is different than the ruminant species where the fetus continues to grow in utero until it is delivered. So, if a cow or goat or ewe goes over its due date, the fetus continues to grow and there will be a dystocia due to fetal oversize. With the variability of gestation length in the horse this fortunately does not occur. There was a study performed in the past where pony embryos were transferred to Thoroughbreds, Thoroughbred embryos were transferred to ponies, ponies were bred to ponies and Thoroughbreds were bred to Thoroughbreds. The rate of dystocias (difficult births) was slightly (but not significantly) higher in ponies with Thoroughbred embryos. These foals were slightly smaller at maturity than the Thoroughbred foals out of a Thoroughbred mare. A small Quarter horse or a Cob stallion should be fine.

The limiting factor for your mare returning to work is the foal. If you are planning to leave him with the other horses, how well will he tolerate that and how well will they tolerate him without his mother? The foal may run all over the place when the mare is taken away even though he seems not to care where she is now. The other horses may not tolerate him after his mother leaves. Her presence may be enough to keep the other horses away from him. If the foal was going with the mother while you work her then the amount of training would be limited by the foal's tolerance for the exercise. You would not want to overwork a 9-week-old foal. I would suggest you play this one by ear and see how everyone reacts to the mare being taken to be worked and adjusting your game plan as needed.

There are several structures that the mare could potentially prolapse when there is excessive straining. These include the vagina, the cervix, the bladder or the uterus. If your mare prolapsed her uterus, the prognosis for subsequent pregnancies is unknown. Her chances for getting pregnant depend on the amount of damage that occurred while the uterus was prolapsed. The amount of damage is also related to the amount of uterus that was prolapsed and how long the tissue was prolapsed. When the uterus is prolapsed, the broad ligament is stretched. This can cause problems with the nerves to the uterus, the blood supply, the lymphatics and potentially the muscles. If there are problems with the nerves, the uterus may not contract properly and it will be difficult to push fluid out of the uterus. If the blood supply is affected, the uterus can be compromised as well. If the lymphatics are affected, again there may be a drainage problem. If the muscles are overstretched, they may not contract as they should again resulting in problems with fluid in the uterus. If the uterus was out for a long period of time, tissue damage could occur that would compromise the mare's ability to carry a foal to term. I would suggest allowing the uterus to rest for as long as possible prior to attempting to rebreed her. Sixty days of sexual rest should be beneficial. I would have your veterinarian evaluate at her foal heat and one or two of the subsequent heats. You want to evaluate the presence or absence of fluid, the general appearance and feel of the uterus as well as the presence or absence of bacteria in the uterus. Future fertility will be dependent upon what your veterinarian finds during these examinations.

In late pregnant mares, it is not uncommon for the mare to stock up. Typically, it is in the hind limbs. Exercise should help keep the filling under control. Has the filling increased in spite of the exercise or is it staying the same? If the filling is stable, I would suggest continuation of the exercise. Some people will place a support wrap on the legs to help control filling. Others will apply a sweat in an attempt to pull the filling down. The choice for any of these treatments is related to the severity of the filling. If you think the filling is excessive or the mare is not close to foaling, I suggest that you have your veterinarian evaluate the mare.

The fear with modified live vaccines is the potential for return to virulence and shedding (such as with EVA vaccination). Our vaccination protocol calls for vaccination against Rabies in November. I would not suggest that you disregard your veterinarians advice based upon my vaccination schedule. Your veterinarian is familiar with the prevalence of problems in your area. For example, we vaccinate for botulism in Kentucky because there have been problems with botulism, but this is not the case in other areas of the country. Due to this, I am reluctant to recommend a generalized vaccination protocol for pregnant mares.

With respect to deworming with the Panacur powerpak: the Intervet Web site contains labels for the various dewormers. It states that a single dose has been tested for safety in the pregnant mare but that the 5 day double dose treatment has not been evaluated for safety in the pregnant mare. A majority of the sources that I investigated suggest deworming 24 to 48 hours post foaling to prevent the post foaling rise in shedding of parasites. There is much discussion concerning deworming in general. It appears that we need to use minimal dewormers and deworm at the time when the drug will have the optimum effect. To do this, we need to be familiar with the life cycles of the various parasites. The thought is the current regime of deworming every X weeks is contributing to the development of resistance to the dewormers.

Whether to breed the mare or not depends on the severity of her ataxia. As the pregnancy progresses, the mare will become heavier and may have difficulty with her coordination. This is a case where you need to discuss the question with your veterinarian. This is a judgment call and cannot be made without examining the mare. To my knowledge, there have been no reports of transplacental transmission of EPM in the horse.

There are several causes of an enlarged ovary. If the mare was pregnant at some point from the May breeding, the enlarged ovary may be a normal finding. From about 36 days to 110 days post ovulation, the endometrial cups are present. These secrete eCG (equine chorionic gonadotropin, formerly known as PMSG). During this time, the mare produces follicles and the eCG causes them to luteinize and produce progesterone to maintain pregnancy. The ovaries feel somewhat enlarged due to the multiple follicles and luteinized follicles present. A hemorrhagic follicle can be very large and cause the ovary to feel large. These typically will go away with time. A granulosa cell tumor can also cause an enlarged ovary. These will cause the mare to stop cycling. Removal of the ovary will allow the mare to return to cycling although the time from surgery to restarting of the cycle is variable. Par ovarian cysts, which are cysts right next to the ovary can give the false impression of an enlarged ovary. An ultrasound examination of the ovary can give you a better idea of what is actually present on the ovary.

The question as to breeding a mare with heaves depends on the severity of the disease. The amount of oxygen the horse can extract from the air as it breathes decreases as the severity of the disease increases. When the mare is pregnant, not only does she need the oxygen but her foal does as well. COPD is similar to asthma in humans. Exposure to certain antigens - pollen, dust, etc. incites a response in the horse. There may be a genetic component to COPD as it relates to the allergic portion of the syndrome. There are also other questions to answer when considering breeding a 20-year-old mare. Is she reproductively sound? Does she accumulate fluid when bred, does she have a uterine infection, how well does she clear fluid, is her external conformation good enough to prevent infection and aspiration of air or feces?

A red bag occurs when there is premature placental separation. There are several causes. The most common are due to fescue or placentitis. With fescue, there is an ergot alkaloid present on the fescue that causes the placenta to become thickened. When parturition occurs, the foal cannot push through the placenta. The foaling process continues and the chorio-allantois (the red portion of the placenta) appears at the vulva instead of the amnion (the white bag). If the bag is not opened immediately, the foal suffocates. These mares also typically do not develop an udder prior to foaling. Placentitis is another potential cause. Placentitis most commonly is caused by an ascending infection. The infection begins at the cervix and travels forward. If the infection is severe enough, the placenta will separate from the uterus. The placenta will also become thickened. Most of the foals in this situation are weaker due to a systemic infection and cannot punch through the placenta. In your case, it may have been due to the position of the foal. If the foal was presented in a true breech presentation where the hind end is coming first, there was nothing to break through the placenta. In this case, the foaling process began and the mare was going through the proper steps. At the stage where the foal's leg should have broken through the placenta, this did not occur. The process continued and the placenta detached and appeared at the vulva. These are difficult dystocias to resolve as there is not enough room for the foal to be delivered in this position. The likelihood of this occurring again is fairly low. Unfortunately, it was just "one of those things."

The chances of success are more a function of the effort put into success than where the horse is located. It is important to know when the mare is in heat in order to breed her at the appropriate time. If the mare shows heat better at home, that would be one reason to breed her from home. This should also help decrease your veterinary expenses as the mare should not need to be examined as frequently. Does the stallion's semen handle being transported? Although it is only a half hour away, if you are transporting semen, it may not be a half hour from collection to insemination. Your schedule, the veterinarian's schedule and the stallions schedule will all need to be coordinated for optimum results. It is impossible to determine how the mare will behave if she is sent away to the breeding farm again. Many times when mares are sent to breeding farms, they are in pastures with other horses. When this happens, the horses have to determine the social hierarchy. This can cause a great deal of stress in some horses and be no big deal for others. As you can see, there are many factors to consider when planning to breed a mare.

The process of udder development and milk production involves an interaction of ovarian and adrenal steroids, prolactin, growth hormone, insulin, thyroid hormones and oxytocin. In older mares, Cushing's (pituitary Adenoma) may result in abnormal production of milk in the udder. Some feeds and forages may contain compounds that cause the udder to fill. You can have your mare tested for Cushing's disease using a dexamethasone suppression test. If the results are abnormal, the mare can be treated with pergolide, which may help decrease the udder.

This is an area that is definitely not my strong point. I will give you some of my clinical impressions. The bottom line is it depends. The resultant offspring will generally not outgrow their genetics. That is you should not end up with offspring that are larger than the larger parent. Which parent will contribute the most to the height of the foal is the question. This may depend on the individuals in question. There are some stallions that we deal with that pass on their size. Many of their offspring are much larger than the mare. On the other hand, there are some mares that seem to be dominant in passing on their traits. If you have bred your stallion and/or have some foals from the mare, you may be able to get an idea of the dominance of their traits. I am not referring to dominance in the true genetic dominant/recessive traits but rather the influence that parent has on the resultant offspring. If your stallion's foals tend to be similar to his size regardless of the mare's size, he may have a strong influence. If however, the foals seem to be closer in size to the mare's, the mare may have the greater influence. The same will be true from the mare side. I hope that this helped you, this is a gray area and difficult to explain clearly.

The first thing that comes to mind is placentitis. Placentitis usually is detected by an enlarged udder or milk dripping prematurely or by a vaginal discharge. The placenta can be examined by your veterinarian via trans-rectal ultrasonography. They will measure the thickness of the placenta. If the placenta is abnormally thickened, the mares are usually treated with systemic antibiotics, double dose of regumate, flunixin and pentoxyfiline. Most cases of placentitis are ascending. The bacteria enters the uterus through the cervix and ascends away from the cervix. The presence of the infection in the region of the cervix causes inflammation and edema in the placenta, which shows up as thickening. I suggest having your mare evaluated as soon as possible. If this is placentitis and is untreated, the infection will progress and you will most likely loose the pregnancy. The foal dies due to septicemia (systemic infection) and outgrowing the functional part of the placenta. Early treatment increases the likelihood that you will have a live foal. The foal may need some medical management when it is born. The severity of the fetal compromise is related to the severity of the infection. Another cause would be Cushing's. Cushing's is due to a pituitary adenoma. This affects the secretion of hormones from the pituitary, some of which are related to milk production. Placentitis is more likely.

It is not necessary to remove salt from the mare's diet during late pregnancy. It is important that horses have access to fresh clean water at all times. The horses themselves regulate how much salt they will eat when the salt is available free choice. They usually will not consume too much. This thought may be related to the fact that in the past, many water sources would freeze when the mares were in late pregnancy. In the case where fresh water was not available at all times, too much salt could cause problems.

If you plan on breeding the mare early (before she would naturally begin to cycle) she needs to be put in a lighted stall at night. The mare needs to be exposed to a total of 16 hours of daylight. A 150 watt bulb in a 12x12 stall should provide sufficient light. Mares will begin to cycle 50-75 days after the lights start. Otherwise, the mare will probably start cycling in late March to early April. When she begins to show heat, you should have your mare evaluated by your veterinarian. They will palpate and ultrasound her uterus, possibly take a uterine culture and cytology and if she is in heat, evaluate her cervix to see if it relaxes properly. I am assuming that she has not had any foals before. If that is the case, she may suffer from the older maiden mare cervix. When a mare is in heat, her cervix should relax to allow fluid and debris out of the uterus and semen in. This does not occur in some older maiden mares. When the cervix does not relax properly, fluid may accumulate in the uterus and cause inflammation. Inflammation results in the production of more fluid, which causes more inflammation .... You should also choose a fertile stallion to breed her to. I would ask the breeding farm if they know what the first cycle conception rate is for their stallion. You would like the number to be greater than 60%. This means that after all the mares in a stallion's book have been bred the first time, 60% will be pregnant. After the second cycle, a total of 84% of the mares will be pregnant and after the third time on the remaining mares, 94% of the mares in the book will be pregnant. A stallion's book is all the mares he will breed in a given breeding season. As you can see as the first cycle pregnancy rate decreases, it will take more attempts to get the same percentage of mares pregnant. That means it will cost more money as you may have to breed more cycles to get a pregnancy. The mare does not need any special supplements. A well balanced ration in combination with good quality hay and pasture and access to clean water should be sufficient. The mare should not be overly fat or thin. You should have an unbiased person evaluate the body condition of your mare. Most horses are somewhat overconditioned. The costs to maintaining the mare during pregnancy are relatively minimal. It would be advisable to have her examined for pregnancy several times after the initial check at 14-16 days post ovulation. She will need her routine vaccinations plus the vaccination against equine herpes virus type 1, which is given at 5,7 and 9 months of pregnancy. The veterinary costs to get the mare in foal vary from region to region and also depend on how the mare is bred: pasture bred, live cover/hand bred, artificial insemination at the farm, artificial insemination with shipped cooled semen or artificial insemination with frozen semen. These have been listed from least expensive to most expensive. Finally, if you will have someone else foal the mare for you, there will be a foaling fee and board fee.

Whether to try again or not is a decision for you to make. Hopefully, I'll give you some information to help you with the decision. As mares age, so do their eggs. Pregnancy loss is higher as mares get older.

That being said, there are plenty of 20+ year old mares having foals consistently. Do you know when she lost her pregnancy? We usually examine mares for pregnancy at 14-16 days post ovulation, 28-32 days, 42-45 days, 60, 90 and 150 days. Determining when the mare lost her pregnancy can give you some idea of the cause. Early pregnancy loss may be due to uterine infection, uterine inflammation or genetic causes.

Pregnancy loss at 60-90 days may be due to uterine fibrosis or abnormal lymphatic. Later abortions may be due to infectious causes such as ascending placentitis, herpes virus or Leptospirosis. Genetic causes can cause losses anywhere in the pregnancy. I would suggest a reproductive evaluation if you plan to breed her. Your veterinarian will palpate and ultrasound the reproductive tract evaluating the consistency and appearance of the ovaries and uterus. A uterine culture and cytology may performed as well as a uterine biopsy. The conformation of the external genitalia will be evaluated to see if the mare needs a Caslicks suture. Based upon the information gleaned from the examination, you can make a decision about your mare's reproductive future.

It is not unusual to see red areas in the snow where horses urinate. There are substances in the urine that oxidize and form a red pigment. If you are still concerned that it is blood, I would either attempt to catch a sample in a container before it hits the ground and evaluate the color or have your veterinarian examine the mare. Your veterinarian can determine if the mare is still pregnant by trans-rectal palpation.

There are a variety of potential causes of pregnancy loss. Mares can conceive with a uterine infection, but will not remain pregnant.

Inflammation will also cause pregnancy loss. The biggest problem we see with older maiden mares (yes, 7 is older for a maiden mare - reproductively speaking) is failure of the cervix to relax properly. This makes it difficult for the mare to leak clear fluid from her uterus and can contribute to inflammation. As I mentioned in an earlier question, I don't think that low progesterone as a primary disease occurs very often. The low progesterone values are usually secondary to something else such as infection or inflammation. I would suggest palpation and ultrasound of your mare when she is in heat and out of heat. We want to observe the follicles, but also look at the uterus to see if there is any free fluid and if the edema present is appropriate for the stage of cycle. Post ovulation, when the mare is out of heat, we want to make sure the edema has gone away. If not, there is inflammation present in the uterus. We also want to make sure there is no fluid present. If fluid is present, the mare will have to be treated aggressively during breeding with uterine lavage and ecbolics (drugs to cause uterine contraction) such as oxytocin or Estrumate. I would also manually palpate the cervix to determine if it is functioning properly. The cervix should be relaxed when the mare is in heat.

Finally, a uterine biopsy could be performed to examine the uterus at a microscopic level to see if there are any changes such as inflammation, scarring (fibrosis), abnormal lymphatics or abnormal blood vessels.

Could the Johnson grass have caused the abortion? Possibly. Johnson grass contain cyanide-type compounds as well as accumulating nitrates in the plant. To cause an abortion, the mare would have to consume a sufficient amount of the plant. We don't know how much Johnson grass was in the hay or how much she consumed. Without having a necropsy performed on the aborted fetus, it is difficult to assign a specific cause to the abortion.

The need for supplemental progesterone for pregnancy maintenance is a controversial situation. There are many causes of pregnancy loss in the horse. I believe that true luteal insufficiency is a rare occurrence. Luteal insufficiency is when the corpus luteum (CL) does not produce enough progesterone. The CL occurs after the mare ovulates. Mares with a uterine infection or inflammation will produce prostaglandin in the uterus. Mares in pain will also produce prostaglandin. Prostaglandin is the drug we use to lyse the CL or short cycle the mare. When we give prostaglandin, the CL stops secreting progesterone and the mare will come back into heat. If the mare comes back into heat and she was pregnant, she will lose the pregnancy. You can see if she secretes her own prostaglandin, it will be difficult to stay pregnant. If a uterine infection is the cause of prostaglandin secretion, the use of progesterone would not be advised.

Progesterone decreases the response of the uterus to an infection. If you give progesterone on top of a uterine infection, you could make the infection worse and cause a pyometra. These can be difficult to treat. I would suggest that you have your veterinarian perform a reproductive examination on your mare when she comes into heat. Your veterinarian will palpate and ultrasound the mare's uterus, perform a vaginal speculum examination and perform a uterine culture and cytology. If these are normal, and you want to evaluate progesterone, it should be at least 5 days after the mare goes out of heat.

In a large study of Thoroughbred farms, it was found that there was a 12% pregnancy loss between 14 and 42 days and a 12% loss between 42 days and foaling. Some of these may have been due to uterine infections, genetic abnormalities and other uterine problems. In older mares, there are other reasons for pregnancy loss. Some of these can be related to aging changes in the uterus such as scarring, abnormal lymphatics or abnormal blood vessels. Other aging changes are seen in the mare's oocytes (eggs). A neat study performed some years ago transferred embryos from old mares in young mares and embryos from young mares into old mares. The pregnancy rate was higher in the young mares embryos into the older mares. This showed that it was the embryo causing the pregnancy loss and not the uterus. The immune system in older mares is not as good as that of younger mares. Therefore, older mares can be more prone to uterine infections. As mares get older and have more foals, the conformation of their vulva can change. The anus becomes sunken and the vulva slopes at a greater angle than when the mare was young. This increases the chance of uterine contamination. The uterus in older mares becomes more pendulous (hangs lower in the abdomen). This makes it more difficult for the mare to clear fluid from her uterus. A complete reproductive work up would be in order if you plan to breed the older mare.

The decision to culture the mare is usually based upon the clinical impression of the veterinarian after examining a mare. In live cover situations, many breeding sheds require proof of a negative uterine culture. This is to prevent the potential spread of pathogenic organisms via a sexually transmitted route. If this is not a requirement, I base my decision to perform a culture and cytology on my examination. If there is free intrauterine fluid or what I consider to be excessive uterine edema, I will culture and take a cytology of the mare's uterus. If vaginal speculum examination shows an inflamed vagina or cervix, I will perform a culture and cytology.

EVA or equine viral arteritis is a sexually transmitted virus. It is present in the semen of a shedding stallion. I would suggest testing your stallion for EVA. This can be done with a simple blood test. If he is negative, you may consider vaccination. If you vaccinate the horse, he will need to be quarantined for 30 days to prevent the potential spread of the virus if he sheds any virus due to vaccination. If he tests positive, you will need to have a sample of semen tested for the virus to determine if he is shedding the virus or just has antibodies to the virus due to exposure at some point. If the horse is shedding virus, he can be bred to vaccinated mares safely.

If you plan to offer AI breeding, you will need to be able to collect semen from the horse. Your veterinarian may offer this service or may be able to assist you in setting up a program. Training a horse to be collected requires patience and time to work slowly with the horse. Some pick it up quickly, others require a little more time. The key is to stop the training sessions before frustration sets in on the human or animal side. I would suggest performing a longevity trial on the extended semen using several different semen extenders and antibiotics. This will help you determine if the semen is capable of surviving the extension and cooling process. You will also find out which extender-antibiotic combination works best for the horse.

There is some thought that there may be a genetic component to parrot mouth (overbite). One would guess that a potential sire would not be related to the grand sire so that would decrease some of the chance for the trait to be carried on if the cause in your mare is genetic in origin. There is a chance (50%) that the problem came from the mare. If you know of any of her siblings that are affected, her offspring may be affected as well. I congratulate you for being concerned about the consequences of breeding your mare.

There are no specific exercises that I am aware of that can be used to give these results. An overall exercise program in combination with as much turnout as possible will give the best results. If the mare has not been used for riding in a long time, I suggest starting her back to work slowly. Ideally, one would want to start with some ground work or round pen work before progressing to riding again.

Breeding on foal heat is a subject that will elicit many opinions. With foal heat breeding, the pregnancy rate is lower than on subsequent cycles. The pregnancy loss rate is higher than mares bred on subsequent cycles. A majority of the data for these statistics comes from large commercial breeding farms. A study performed at Texas A&M looked at foal heat breeding in the population of prison mares. These mares are selected for fertility and bred to stallions of good fertility. In that study, there was no difference with pregnancy rate if the mare was bred on foal heat or if foal heat was skipped and the mare was bred on subsequent heats. Based upon the history you gave, I would skip foal heat and breed her on the subsequent cycle. If she is due to foal later in the year, you can shorten the interval to the second heat with the use of prostaglandin. I would suggest having your veterinarian palpate and ultrasound the mares uterus when she is in foal heat to make sure it is in good shape. That is, is the uterus involuting, is there any fluid in the uterus, or are there any more abnormalities present.

In my practice, there are some farms that routinely give Banamine (flunixin) post foaling. My personal preference is to give only if needed. Using flunixin routinely would be similar to taking Tylenol because there's the potential that you'll be uncomfortable later in the day. Oxytocin is not routinely used post foaling. It is usually used in mares with a retained placenta or with excessive intrauterine fluid several days post foaling. Normal mares that are turned out regularly after foaling and are being vigorously nursed by the foals should not have a problem with fluid accumulation.

If you haven't done so already, I would suggest having your veterinarian exam the mare to help answer your questions. In mares with chronic pain, it is not uncommon to use long term anti-inflammatory products (usually phenylbutazone). This is usually with mares that have chronic founder. The horses are also treated with Gastroguard or Ulcerguard.

The dose is adjusted to use the minimum amount of drug that has the desired level of pain relief. There are shoeing techniques that can be used in horses with suspensory problems. The goal with any pain problem in the pregnant mare is to determine the cause of the pain. If possible, the cause should be treated to eliminate the production of pain. If that is not possible, the next step is to treat the mares with drugs or therapy that will provide pain relief. Painful mares are difficult to get in foal and keep in foal. The reason for this is that in the pain response, prostaglandin is released. Prostaglandin is the substance used to lyse the corpus luteum, which produces the progesterone that maintains pregnancy.

Melanomas located on the skull most likely would not affect cyclicity. In order for the melanoma to have an impact, it would have to obstruct the communication between areas of the brain (hypothalamus and pituitary) and the ovaries. This would be difficult unless the tumor was within the brain. If that was the case, I would suspect that you would see other signs as well. I would look at other potential causes of decreased ovarian activity. Some of the potential causes of decreased activity would be a granulosa theca cell tumor, uterine infection, ovarian senility, stress and negative energy balance (extremely thin). These are a few that came to mind quickly, there are many others. I would suggest having your veterinarian perform a complete breeding soundness examination if possible in an attempt to sort out what the problem may be.

Dependent edema is not uncommon in late pregnant mares. The severity varies from mare to mare. The cause may be due to the fetus compressing the abdomen and decreasing fluid movement or decreased movement of the mare. In some mares, the edema will become so severe that it is very uncomfortable to move. Turnout is probably the best thing as it will allow the mare to move around and hopefully decrease the amount of edema. In some cases, anti-inflammatory drugs such as flunixin or phenylbutazone have been used. Is the mare also developing an udder? If the edema is "late term edema," she should also be developing an udder. If there is no udder development in the face of the edema, I would suggest having her evaluated by your veterinarian. She should also be evaluated if you feel the edema is too severe. Mares that developed ventral edema late in pregnancy will usually lose the edema within several days of foaling.

It's probably an oops - is it too late or can we still separate the colts from the fillies?

Yes, it's possible for a yearling filly to be bred by and become pregnant to a yearling colt. There are a few caveats however. Puberty occurs in the colt at about 1 1/2 years of age. In a study looking at puberty where puberty was defined as the first ejaculate containing greater than 50 million sperm with greater than 10% motility, the average age of puberty was 83 weeks (1 year 7 1/2 months) but ranged from 57 to 97 weeks (13 months to 1 year 11 months). There were 15 light horse colts in the study.

Puberty occurs in the filly at 12 to 24 months of age. So for pregnancy to occur as early yearlings, they both would have to have reached puberty. As they progress through the yearling year, the likelihood of pregnancy occurring increases.

There are several methods available to get a ballpark idea of the age of a pregnancy. Due to the variation in size of foals at birth and the range of normal gestation length (320 to 360 days), you will only be able to predict within 4 to 6 weeks of foaling date. What that means is these methods will get you within about 60 days of the correct age. Some of the methods include measuring the size of the fetal eye socket, measuring the size of the fetal aorta and measuring the placental thickness. These are measured using an ultrasound. Normal values have been determined for these measurements. Most of the work has been performed on Thoroughbreds with a few other light horses. As the pregnancy progresses, the udder will start to fill. This usually starts two to three weeks before foaling. The muscles in the area of the tail head will relax and the vulva will elongate. These changes occur close to foaling. A wax-like drop will be seen on one or both teats shortly (usually about 48 hours before foaling). These changes are more predictable in mares that have had foals in the past. Maiden mares have been known to have the changes occur in a very short period of time. As you get closer to the expected time of foaling, you can test the mammary secretions for calcium. There are several test kits commercially available for this purpose. These kits are more reliable at predicting when the mare will not foal than when she will. However, this will still help you get sleep.

As for an emergency kit, there is not much you will need to add to your foaling kit. In the foaling kit I would have clean towels, soap (ivory dish soap, betadyne scrub, chlorhexadine scrub), bucket, cotton or towels to wash the mares vulva and udder, tail wrap, bottle and lambs nipple, dental floss (to tie umbilicus if needed), dip for the navel (chlorhexadine solution, betadyne solution [not strong iodine]), enemas and disposable hand gloves. I would suggest talking to your veterinarian about any drugs he feels you should have on hand for the mare as well as any other emergency supplies for the foaling kit. It is important for there to be good communication between you and your veterinarian during this time.

Since we are talking about reproduction, my guess is that you're referring to the broad ligament, which is the ligament that supports the uterus and not the suspensory ligament in the legs. The most common problem seen with the broad ligament in pregnant mares is a uterine artery rupture that bleeds in to the broad ligament and forms a hematoma. These are uncommon but not unheard of in mares the same age as yours. The signs you saw are indicative of pain that can be from a variety of causes. Typically, when a mare ruptures a uterine artery, they do not respond to one dose of Banamine and recover in one hour. These horses are uncomfortable for a long period of time, depressed, sweaty, trembling, increased heart rate and very pale mucus membranes.

These signs are due to hypovolemic shock. A variety of treatments have been used including sedation and keeping the mare quiet, fluids, plasma transfusions and drugs to aid clotting. There is not a great deal of information in the literature about rebreeding mares with a uterine artery rupture that has healed. As uterine artery ruptures usually occur in older mares, it is thought that the makeup of the blood vessels is compromised with age allowing the rupture to occur. My clinical impression would be that some of these mares can be rebred and have another foal uneventfully, but I don't know what percentage that would be. Not all uterine artery ruptures are saved by the broad ligament.

In some cases, the broad ligament ruptures as well and the mare bleeds into the abdomen. This is fatal to these mares. Your mare obviously experienced a painful episode but it would be difficult to pin it on the broad ligament. The broad ligament can be examined using rectal palpation and ultrasound in an attempt to see if it was related to the incident with yur mare.

There are a variety of reasons that can cause stiffness in the hind end. I would suggest having your veterinarian evaluate the horse. Mares can become more uncomfortable and move around slower as they get closer to foaling. This is due to the size of the abdomen and may also be related to any dependant edema. When the mares don't move as much, they develop a plaque of edema on their belly and the legs may also become stocked up. This will result in a stiff appearance and slow movement. Problems with compression of a nerve are usually seen during the foaling process, typically when the foal spends a long period of time in the pelvis. We see this in dystocias (difficult births) and unattended foaling where the foal may be slow to be delivered. Recovery of mares from dystocia induced paresis depends on severity and time affected prior to treatment.

There are many broodmares that have had laminitis. If the mare becomes pregnant, she will gain weight during her pregnancy. In cases of laminitis, we try to keep the horses as light as possible to decrease stress on the laminae. If the mare has recovered from the laminitis, there should be minimal risk to breeding her. It is important to remember that horses that have developed laminitis are more prone to developing laminitis again. You will need to be diligent in your care of her to prevent this from recurring. Mares that are in pain due to laminitis produce prostaglandins, which can have a negative impact on getting them pregnant. I would suggest consulting with your veterinarian regarding the resolution of the laminitis and his feelings on the impact of a pregnancy on the mare. By waiting another year or two, it may be slightly more difficult to get the mare in foal. Each animal is an individual so it is difficult to make general statements. Our mare was a 15-year-old maiden and she became pregnant on the first service with no extra treatments needed. I've also worked on "young" maidens that require numerous breedings and a great deal of work to get pregnant. You may want to wait one year to work out managing the mare through the year to avoid laminitis so that when she does become pregnant you've had a history of how she needs to be managed.

Yes it's possible to breed her at this age. However, there are some issues you will have to deal with. Your mare most likely will suffer from "old maiden mare syndrome." We see this in maiden mares starting about 7 years of age. The cervix in these mares does not relax as it should when the mare is in heat. When a mare is in heat, her endometrium produces fluid. This is to allow the uterus to remove contaminants such as bacteria and dead sperm. The fluid is removed from the uterus in two ways. One is by contraction of the uterus pushing the fluid out through the cervix. The other is via the lymphatic system. If the cervix does not relax, it is difficult for the mare to remove all the fluid. Fluid in the uterus can also produce inflammation. The horse responds to inflammation by producing more fluid to remove the source of inflammation. This leads to a vicious circle. Over time, some of the lymphatics will become blocked resulting in an increased accumulation of fluid. We treat these mares with uterine lavage and drugs such as oxytocin and cloprostenol to aid in uterine contraction and evacuation. In some cases, we have used misoprostol (prostaglandin E) to aid in cervical relaxation.

It is difficult to say if a pregnancy would be harmful to the mare. She is pushing the upper limits of age to have a first foal. I would suggest performing a uterine biopsy to evaluate the condition of the uterus. As mares age, the blood vessels to the uterus change. The collagen present becomes frayed and loses integrity. The more compromised the vessels are, the greater the chance of a uterine artery rupture. The condition of the vessels can be crudely evaluated on the biopsy. Additionally, following the mare through a cycle with palpation and ultrasound will help you determine if she pools fluid. I would also evaluate the cervix manually when she is in heat to see if the cervix relaxes. With this information in hand, you and your veterinarian can reach a conclusion regarding the risks and benefits and likely success of a pregnancy in your mare. If you decide the mare is not a suitable candidate to carry a foal to term but want a foal from the mare, you may consider embryo transfer.

There are two sites where fluid can build up. One is in the lumen of the uterus and the other is in the endometrium. Free fluid in the lumen can be due to infection, inflammation or poor drainage. Prior to breeding, the mare should have a negative uterine culture. The free fluid can be treated with uterine lavage and drugs such as oxytocin and cloprostenol to cause the uterus to contract and push the fluid out. Excessive fluid in the endometrium (or excessive edema) could be due to inflammation or poor drainage as well. Treatment also includes lavage and drugs to cause the uterus to contract. On occasion, we use anti-inflammatory drugs such as flunixin, phenylbutazone or corticosteroids such as dexamethasone or prednisolone to decrease inflammation. Once the cause of the fluid is determined in your mare, it can be treated. Mares that develop fluid are more difficult to get in foal but can be managed successfully.