artificial insemination. Disorders and diseases

Disorders and diseases
When your mare has failed to come into heat by May, when she's already been back for the third time, or when she's been in heat now for three weeks straight and is not showing signs of pregnancy even though the stallion is worn out from covering her, maybe it's time to call in expert help.

In the last 20 years, Equine gynaecological research has enjoyed tremendous development, and our efforts are increasingly being accepted. Even so, a certain amount of hesitation sometimes exists when it comes to calling in a veterinarian for a gynaecological patient. Some reasons for this might be:

A certain instinctive resistance to rectal exams ('all that messing around inside a horse certainly can't be good for her!').
Since sterility problems are internal and often invisible from the outside, people tend to think, 'If there are no symptoms, the horse isn't sick.
The costs for completing meticulous gynaecological testing (possibly including treatment) can be considerable, especially when you consider that the veterinary will have to make several visits to see a single mare and that these costs will be the same., no matter if the mare is a top thoroughbred or a pet Shetland pony. (4) Finally, veterinary interventions can only increase the chances of a pregnancy; nobody can guarantee success. This means that disappointments can still occur.

Causes for failure to become pregnant that involve the functioning of the stallion or the handling of the breeding procedure have already been discussed at length. What follows, then, are certain problems stemming from the mare. Since it is impracticable to try and cover every one of the problems affecting the female reproductive system, I'm limiting myself to the most common ones.

Abnormalities of the ovaries
During the winter, most mares go through a period in which their ovaries are inactive (the ovaries can be felt as small and hard). This is also known as the anestrous period. In the spring, signs of activity start to appear. Usually, however, this begins with the formation of very small follicles, a phenomenon known as MFO (multi-follicular ovaria). Mares with MFO often show certain signs of heat over a lengthy period of time, but these signs never amount to a real ovulation. If a rectal exam or ultrasound done during the winter or early shows that such is the case, to be considered as normal. If this is still the case in May, however, there may be problems involved. Luckily, there are several ways of attempting to affect the behaviour of the ovaries by means of hormones and they sometimes work.

Another familiar problem is that the corpus luteum may continue to produce progesterone so that the mare will fail to come into heat in spite or follicular activity. It is possible that the mare has been pregnant and has miscarried, but there is usually no explanation for this phenomenon. Treatment in this case involves an injection of prostaglandins (the 'heat injection').

Another problem, but one that is only rarely found, is a mare with very small hard ovaries. These mares have very little chance of ever becoming pregnant. Tumours and cysts are other rare abnormalities. Hormoneproducing tumours sometimes cause a mare to exhibit extreme behaviour.

Problems involving the uterus
The most common cause of fertility problems among mares is a uterine infection. Often, such a uterine infection is fairly free of symptoms, while in certain cases the problem will be apparent in the form of an abnormal fluid (e.g. pus) being excreted onto the vulvar lips, tail hairs, thighs, and hocks. Uterine infections are almost always associated with mating or insemination. Every mating or insemination, no matter how carefully conducted, introduces a number of bacteria into the uterus. The uterus has a natural resistance to such organisms, and this resistance is highest when the mare is in full heat. Some mares, however, are more susceptible to infections: older mares, mare, that are not in full heat (e.g., anestrous), or mares in foal heat that have had problems releasing the afterbirth. Among some mares, however, it is difficult or impossible to determine the cause of their susceptibility to infections. Once such a mare has been cured (at considerable trouble) of a uterine infection, it would be advisable, as a precautionary measure, to give her an antibiotic vaginal flush 3 to 6 hours after having her serviced.

A uterine infection can be caused not only by actual pathogenic bacteria, but also by bacteria normally found in the horse's environment such as the bacteria in manure. Fungi and yeast's can also cause infections. The real problem horses in this respect are the ones that have been treated for a uterine infection caused by one micro-organism and then come down with another infection caused by another micro-organism.

Among older mares, cysts (fluid-filled blisters) are often seen in the uterus. If there are only a few of them, this should be no hindrance to pregnancy.

Damage to the Cervix
The Cervix can become damaged both due to a difficult birth and to a difficult mating procedure. The Cervix forms the barrier between the vagina (which is not sterile) and the sterile uterus. Damage to the Cervix, therefore, increases the risk of infection in the uterus Poor closure of the Cervix can also result in miscarriage.

Problems involving the vagina and vulva
A fairly frequently occurring problem is 'wind-sucking' (pneumovagina, or the aspiration of air and debris into the vagina). In this case, poor conformation of the vulva keeps it from closing properly, during fast gaits and jumping, a sucking sound can be heard. This is especially conspicuous among mares in heat. This sucked-in air (and debris) cause vaginal irritation and infection. The infection can then spread to the Cervix and uterus. Not only does this problem greatly reduce the chance of pregnancy, but it is also seen as objectionable among horses used in sport (if not because of a reduced performance then at least because spectators find it hilarious). Older, thinner horses are more prone to this problem as are young thoroughbred horses due to the increased tilt of their vulvas. An operation can treat this problem.

The second problem is the presence of urine in the vagina (urine pooling), This is most commonly seen in old, thin horses with a defective genital conformation. A small amount of urine need not be a major problem if cleaning is done before covering or insemination. In serious cases, an operation can sometimes help.

One problem (and one that often causes great alarm among mare owners) involves bleeding or haemomhages in the vagina caused by broken veins. This is seen primarily in older horses during the second half of their pregnancy. Although usually not a serious problem, it can occasionally involve such a heavy flow of blood as to require a blood transfusion. Treatment is best done following foaling, but can even be done before that by cauterizing the veins.

A real venereal disease that occurs in the Netherlands is coital exanthema. This
caused by a herpes virus being transmitted during mating. It exhibits initially as fluidfilled blisters that can break open, and a red rash. Although painful, the problem goes away on its, own without treatment, often leaving little white scars behind on the vulva. Obviously, stallions or mares with this disorder should be given time to heal before having them engage in mating.

As a summary, here are possible causes for the most commonly heard complains:

Mare does not become pregnant
- The mare is already pregnant.
- The mare is not being teased properly
- The mare is simply not displaying typical heat behaviour
- The mare is being teased at the wrong time.
The ovaries of the mare are not yet active (she is still in her anestrous period).
- The mare is suffering from a very serious uterine infection.
- A corpus luteum is still active on the ovaries due either to the fact that the mare was temporarily pregnant or for unknown reasons.
- The mare lacks a normally formed reproductive system.
The mare is in heat but does not become pregnant (continues to come back to be served)
- The mare is suffering from a uterine infection.
- The mare is being served at the wrong time.
- The mare is not developing a good follicle.
- The mare is suffering from 'wind sucking'.
- The Cervix is not properly closed.
- There are possible problems involving the management of covering and/or the stallion.

Other problems

The mare remains in heat for a long time or comes into heat irregularly Uterine infection
The mare is still in the transition from her winter anestrous period to her reproducti-ve season and is still producing small follicles (MFO).

Diagnosing pregnancy
The best way to determine pregnancy is to have an ultrasound exam done about 18 days after mating. At that time, there should be an obvious amniotic sac visible. The best time to repeat this procedure is at 25 days after service when an embryo with a beating heart should be visible. Another reason for having an ultrasound exam done is to determine the possibility of twins. Determining twins by means of ultrasound is best done around 15 days after ovulation before the embryos are well embedded since treatment is still possible at that time. Always check early in case of a double ovulation.
When checking by means of a rectal examination, it is possible to feel the presence of a possible pregnancy around 3 weeks after mating because the uterus will have changed shape and will be exhibiting more tension by that time.
At about 5 weeks after mating, an amniotic sac can be felt.
At five weeks, it will be the size of a tangerine;
at six weeks, it will be the size of an orange, etc.
Many different laboratory tests are also available but are usually used only in exceptional cases in which rectal examina-tion is not possible.

In conclusion
It can sometimes happen that the mare will become sick after service and that the foal, too, can become sick. The mare's owner will sometimes think that the problem may be related to a disorder invol-ving the reproductive system, but this is .seldom the case. Usually, what is involved is a respiratory disorder that the mare has picked up during transport to the stud center or during her stay there. Even at a breeding facility where everything possible is done in the way of disease prevention, it can sometimes happen that disease will crop up. This is why it is so important to have mares that are going to be served properly inoculated and to leave sick hor-ses at home.



		Abnormalities of the ovaries Problems involving the uterus Damage to the Cervix Problems involving the vagina and vulva The most commonly heard complains Other problems Diagnosing pregnancy In conclusion
	Disorders and diseases When your mare has failed to come into heat by May, when she's already been back for the third time, or when she's been in heat now for three weeks straight and is not showing signs of pregnancy even though the stallion is worn out from covering her, maybe it's time to call in expert help. In the last 20 years, Equine gynaecological research has enjoyed tremendous development, and our efforts are increasingly being accepted. Even so, a certain amount of hesitation sometimes exists when it comes to calling in a veterinarian for a gynaecological patient. Some reasons for this might be: A certain instinctive resistance to rectal exams ('all that messing around inside a horse certainly can't be good for her!'). Since sterility problems are internal and often invisible from the outside, people tend to think, 'If there are no symptoms, the horse isn't sick. The costs for completing meticulous gynaecological testing (possibly including treatment) can be considerable, especially when you consider that the veterinary will have to make several visits to see a single mare and that these costs will be the same., no matter if the mare is a top thoroughbred or a pet Shetland pony. (4) Finally, veterinary interventions can only increase the chances of a pregnancy; nobody can guarantee success. This means that disappointments can still occur. Causes for failure to become pregnant that involve the functioning of the stallion or the handling of the breeding procedure have already been discussed at length. What follows, then, are certain problems stemming from the mare. Since it is impracticable to try and cover every one of the problems affecting the female reproductive system, I'm limiting myself to the most common ones. Abnormalities of the ovaries During the winter, most mares go through a period in which their ovaries are inactive (the ovaries can be felt as small and hard). This is also known as the anestrous period. In the spring, signs of activity start to appear. Usually, however, this begins with the formation of very small follicles, a phenomenon known as MFO (multi-follicular ovaria). Mares with MFO often show certain signs of heat over a lengthy period of time, but these signs never amount to a real ovulation. If a rectal exam or ultrasound done during the winter or early shows that such is the case, to be considered as normal. If this is still the case in May, however, there may be problems involved. Luckily, there are several ways of attempting to affect the behaviour of the ovaries by means of hormones and they sometimes work. Another familiar problem is that the corpus luteum may continue to produce progesterone so that the mare will fail to come into heat in spite or follicular activity. It is possible that the mare has been pregnant and has miscarried, but there is usually no explanation for this phenomenon. Treatment in this case involves an injection of prostaglandins (the 'heat injection'). Another problem, but one that is only rarely found, is a mare with very small hard ovaries. These mares have very little chance of ever becoming pregnant. Tumours and cysts are other rare abnormalities. Hormoneproducing tumours sometimes cause a mare to exhibit extreme behaviour. Problems involving the uterus The most common cause of fertility problems among mares is a uterine infection. Often, such a uterine infection is fairly free of symptoms, while in certain cases the problem will be apparent in the form of an abnormal fluid (e.g. pus) being excreted onto the vulvar lips, tail hairs, thighs, and hocks. Uterine infections are almost always associated with mating or insemination. Every mating or insemination, no matter how carefully conducted, introduces a number of bacteria into the uterus. The uterus has a natural resistance to such organisms, and this resistance is highest when the mare is in full heat. Some mares, however, are more susceptible to infections: older mares, mare, that are not in full heat (e.g., anestrous), or mares in foal heat that have had problems releasing the afterbirth. Among some mares, however, it is difficult or impossible to determine the cause of their susceptibility to infections. Once such a mare has been cured (at considerable trouble) of a uterine infection, it would be advisable, as a precautionary measure, to give her an antibiotic vaginal flush 3 to 6 hours after having her serviced. A uterine infection can be caused not only by actual pathogenic bacteria, but also by bacteria normally found in the horse's environment such as the bacteria in manure. Fungi and yeast's can also cause infections. The real problem horses in this respect are the ones that have been treated for a uterine infection caused by one micro-organism and then come down with another infection caused by another micro-organism. Among older mares, cysts (fluid-filled blisters) are often seen in the uterus. If there are only a few of them, this should be no hindrance to pregnancy. Damage to the Cervix The Cervix can become damaged both due to a difficult birth and to a difficult mating procedure. The Cervix forms the barrier between the vagina (which is not sterile) and the sterile uterus. Damage to the Cervix, therefore, increases the risk of infection in the uterus Poor closure of the Cervix can also result in miscarriage. Problems involving the vagina and vulva A fairly frequently occurring problem is 'wind-sucking' (pneumovagina, or the aspiration of air and debris into the vagina). In this case, poor conformation of the vulva keeps it from closing properly, during fast gaits and jumping, a sucking sound can be heard. This is especially conspicuous among mares in heat. This sucked-in air (and debris) cause vaginal irritation and infection. The infection can then spread to the Cervix and uterus. Not only does this problem greatly reduce the chance of pregnancy, but it is also seen as objectionable among horses used in sport (if not because of a reduced performance then at least because spectators find it hilarious). Older, thinner horses are more prone to this problem as are young thoroughbred horses due to the increased tilt of their vulvas. An operation can treat this problem. The second problem is the presence of urine in the vagina (urine pooling), This is most commonly seen in old, thin horses with a defective genital conformation. A small amount of urine need not be a major problem if cleaning is done before covering or insemination. In serious cases, an operation can sometimes help. One problem (and one that often causes great alarm among mare owners) involves bleeding or haemomhages in the vagina caused by broken veins. This is seen primarily in older horses during the second half of their pregnancy. Although usually not a serious problem, it can occasionally involve such a heavy flow of blood as to require a blood transfusion. Treatment is best done following foaling, but can even be done before that by cauterizing the veins. A real venereal disease that occurs in the Netherlands is coital exanthema. This caused by a herpes virus being transmitted during mating. It exhibits initially as fluidfilled blisters that can break open, and a red rash. Although painful, the problem goes away on its, own without treatment, often leaving little white scars behind on the vulva. Obviously, stallions or mares with this disorder should be given time to heal before having them engage in mating. As a summary, here are possible causes for the most commonly heard complains: Mare does not become pregnant The mare is already pregnant. The mare is not being teased properly The mare is simply not displaying typical heat behaviour The mare is being teased at the wrong time. The ovaries of the mare are not yet active (she is still in her anestrous period). The mare is suffering from a very serious uterine infection. A corpus luteum is still active on the ovaries due either to the fact that the mare was temporarily pregnant or for unknown reasons. The mare lacks a normally formed reproductive system. The mare is in heat but does not become pregnant (continues to come back to be served) The mare is suffering from a uterine infection. The mare is being served at the wrong time. The mare is not developing a good follicle. The mare is suffering from 'wind sucking'. The Cervix is not properly closed. There are possible problems involving the management of covering and/or the stallion. Other problems The mare remains in heat for a long time or comes into heat irregularly Uterine infection The mare is still in the transition from her winter anestrous period to her reproducti-ve season and is still producing small follicles (MFO). Diagnosing pregnancy The best way to determine pregnancy is to have an ultrasound exam done about 18 days after mating. At that time, there should be an obvious amniotic sac visible. The best time to repeat this procedure is at 25 days after service when an embryo with a beating heart should be visible. Another reason for having an ultrasound exam done is to determine the possibility of twins. Determining twins by means of ultrasound is best done around 15 days after ovulation before the embryos are well embedded since treatment is still possible at that time. Always check early in case of a double ovulation. When checking by means of a rectal examination, it is possible to feel the presence of a possible pregnancy around 3 weeks after mating because the uterus will have changed shape and will be exhibiting more tension by that time. At about 5 weeks after mating, an amniotic sac can be felt. At five weeks, it will be the size of a tangerine; at six weeks, it will be the size of an orange, etc. Many different laboratory tests are also available but are usually used only in exceptional cases in which rectal examina-tion is not possible. In conclusion It can sometimes happen that the mare will become sick after service and that the foal, too, can become sick. The mare's owner will sometimes think that the problem may be related to a disorder invol-ving the reproductive system, but this is .seldom the case. Usually, what is involved is a respiratory disorder that the mare has picked up during transport to the stud center or during her stay there. Even at a breeding facility where everything possible is done in the way of disease prevention, it can sometimes happen that disease will crop up. This is why it is so important to have mares that are going to be served properly inoculated and to leave sick hor-ses at home. Page up