Reproductive Services
The clinic is a BEVA approved centre for artificial insemination using both chilled and frozen semen. Our clinic laboratory is also one of a few laboratories in the country accredited for CEM (contagious equine metritis organism). This is the preventative scheme, overseen by the Horserace Betting Levy Board, to make sure mares and stallions at stud are screened for the venereal diseases that can affect fertility.
Chilled Semen AI
Mares can be dealt with at home, at a boarding stud / stables or admitted to the clinic for insemination with chilled semen. The semen is sent from the relevant stud in a special insulated and chilled container usually for next day delivery or same day, in some instances. The semen has about a 48 hour shelf-life in the container but should be inseminated into the mare as soon as possible. Timing is important and the mare will be examined internally and semen ordered to try and ensure that insemination occurs within the 24 hours prior to ovulation of the follicle. Weekends and bank holidays can make the precise timing difficult. The sperm will live for anything from 12 to 48 hours after insemination, inside the mare. Pregnancy rates will be similar to those achieved by natural service.
Frozen Semen AI
Mares must be admitted to the clinic for insemination and the monitoring leading up to insemination. Once the semen has been thawed the sperm must be kept at a constant 37oC and inseminated immediately. The sperm only live for about 6 hours after thawing so the timing has to be very precisely co-ordinated with ovulation. This is done by closely monitoring the mare at increasingly frequent intervals, as ovulation approaches. Around the time of ovulation, examinations will be made every 2-4 hours. As soon as ovulation is identified, insemination is performed, immediately, often this is in the early hours of the morning. The semen is thawed in a water bath at 37oC and once thawed, which takes about 30 seconds, immediately inseminated using a pre-warmed catheter. To further increase the success rates we use deep uterine insemination, depositing the thawed sperm right next to the end of the fallopian tube, which contains the unfertilised “egg”. To be even more precise, an endoscope can be used to directly visualise the end of the fallopian tube and deposit the sperm directly onto it. This method can reduce the quantity of sperm required to achieve acceptable pregnancy rates, which maybe of advantage if the stallion concerned is dead and semen supplies limited. This endoscopic method is more complicated and expensive than deep uterine insemination.
Thawed sperm are more fragile than fresh or chilled sperm and therefore, not suitable for use in mares with a hostile uterine environment, such as mares at foal heat or older mares or mares prone to uterine infections.
Because of the expense and work involved in using frozen semen it is not recommended to use this technique in a maiden mare, it is advisable to ensure her fertility using natural service or chilled semen AI before embarking on a frozen semen insemination.
Routine Mare Work
The practice does the routine work at a number of local studs and can deal with any mare requiring reproductive examinations. Routine work would include swabbing mares prior to covering, mares should have a clitoral swab prior to natural service, this is looking for any of the venereal bacteria ( CEM, Klebsiella pneumoniae or Pseudomonas aeruginosa). Some studs will also require a blood sample to ensure the mare is negative for EVA (equine Viral Arteritis) and EIA (Equine Infectious Anaemia or “Swamp Fever”) using a Coggins Test.
A clitoral swab can be taken at any time in the same breeding season as the mare is to be covered and the EVA blood sample should be taken within 28 days of being initially covered.
It is strongly advisable that mares also have a cervical or endometrial swab. This swab can only be taken if the mare is in season. The cervical swab not only checks for the venereal bacteria but for the presence of any bacteria inside the uterus and for non-infectious inflammation. The swab should be taken in the first day or two of the in-season period, this allows some time to treat any problem before the mare goes out of season.
Checking the mare’s ovaries once she is in season allows the vet to estimate a likely timing of ovulation and aim towards the ideal situation of a single covering as close to the time of ovulation as possible. Each time a mare is covered an amount of dirt, debris and contamination is deposited into the uterus along with the sperm, therefore, to reduce the risk of an infection being set up, the number of coverings should be kept to a minimum. Also mares should have their vulval area cleaned with fresh water and their tail bandaged prior to covering to reduce any potential contamination. Disinfectants and soaps should not be used.
Internal examinations not only allow the ovaries and their follicles to be monitored, the uterus is examined for oedema, one of the indicators of how well in-season the mare is and also the presence of any free fluid in the uterus which is a warning sign for infections or inflammation of the inside of the uterus which will dramatically interfere with fertility.
Mares can be checked for ovulation, this is useful for knowing when ovulation occurred and it’s timing relative to the last covering, for identifying multiple ovulations and therefore, the mares more likely to have twin pregnancies and for the identification of post-covering uterine infections, which are one of the most common causes of reduced fertility.
Scanning for pregnancy
The identification of pregnancy is important for several reasons,
1. Obviously to identify the pregnancy and avoid the need to return to the stud or be covered again.
2. To identify multiple pregnancies and deal with the situation as early as possible.
3. To ensure the pregnancy is normal and growing at an appropriate rate.
4. Identify mares that suffer early loss of the pregnancy so that they may be returned to stud the same year if appropriate.
Scans should ideally be done at 16 –18 days after covering, again at 25-28 days after covering and a third time at 42 days after covering.
The 16-18 day scan is looking to identify a pregnancy and also the first opportunity to identify possible twin or multiple pregnancies. A twin pregnancy can be squeezed to remove it. Up to 18 days the pregnancies move freely within the uterus and can be manipulated apart to avoid traumatising the remaining pregnancy. After 18 days they implant into the wall of the uterus and cannot be moved, if twin pregnancies are identified after 18 days and they are close together, then attempts to squeeze one is likely to traumatise the other one which dramatically increases the chances of loosing that pregnancy also.
The 25-28 day scan is checking that any pregnancy seen at the first scan is still present and has grown at a normal rate. From 25 days, the pregnancy should contain a heartbeat which is visible on the scan, this is a good sign that the pregnancy is growing, normally and is viable. If no heartbeat is seen the mare should be re-scanned a few days later, if no heartbeat is seen and the pregnancy has not grown, at this stage, abortion should be considered. It is also an opportunity to look for any additional pregnancies that may be some days younger than the initial pregnancy and therefore may have been too small to identify at the first scan.
The 42 day scan is performed to check the pregnancy has grown and is healthy. Most early pregnancy loss occurs prior to 42 days, so if a pregnancy has survived to 42 days it stands a reasonable chance of making it to term. This scan is also a last chance to ensure there is only one pregnancy present.
Sexing
It is possible to identify the sex of the foetus between 60 and 65 days after covering. It is not easy to perform as specific views of the foetus are required and because the scan is performed through the rectum the vet is very limited in the movement available of the probe. If the foetus is lying in an accommodating plane it may be quite straight forward to get the necessary views, if it is not then it may be impossible. If time is not an option one can wait for the foetus to move but this may take upto an hour or more and most mares if not the vet and owners cannot wait that long. After 65 days the pregnancy gets too big and is often out of range of most trans-rectal scanners to get the necessary views.
Barren Mares
Should a mare go through a breeding season and not conceive, then some investigations should be performed to try and find out why, before she is left to go through the winter.
If she has only been covered by one stallion and has not conceived to him previously, it is always worth changing to another stallion. Genetic mis-matches leading to unviable pregnancies, which are lost in the first couple of weeks are thought to be very common. If a mare is covered three times by one stallion, without success and she conceives the first time with a different stallion, it does not prove there was a genetic mis-match between the initial pairing but strongly suggests it and it would not be sensible to try and repeat that initial pairing.
If a mare has not had a cervical swab during the season then this should be performed when she is next in-season. If no obvious reason is found thus far, then an endometrial biopsy should be taken. This is done when the mare is in season, an instrument is introduced through the cervix and a pinch of tissue is taken from the uterine lining. This is sent off to the laboratory for analysis. Depending on the laboratory findings a treatment protocol can be formulated. Once that treatment has been administered and sufficient time to allow the treatment to have it’s effect, the biopsy should be repeated to make sure it has had it’s desired effect.
If the biopsy does not produce a reason for the infertility, then an endoscope can be used to look at the entire inside of the uterus which may provide a diagnosis for the infertility.
Caslicks
This procedure still causes controversy today.
The mare’s vulva is designed to be an airtight seal to the vagina. As mares get older, have more foals or just aren’t very fit, their abdominal wall slackens. This means the abdominal contents, the guts, drop. Since the rectum and anus are attached to the guts, they get pulled forward, over the pelvis, which obviously can’t move. Since the vulva is also attached to the rectum, it too, moves upwards. In the original plans, the top of the vulva was supposed to be level with the brim of the pelvis. This situation allows the air-tight seal to work. However, if the vulva is pulled upwards, as described above, then the portion raised above the level of the pelvic brim, no longer acts as a seal and allows air into the vagina. Unfortunately air entering the vagina also brings bacteria with it. Bacteria in the vagina also get onto the cervix and when the cervix opens i.e when the mare is in season, the bacteria can get into the uterus.
To correct this abnormality, we can perform a Caslicks Operation. This means stitching the portion of the vulva that sits above the pelvic brim and returning the rest of the vulva to an air-tight seal. Once stitched, the skin edges heal and the actual suture material can be removed but if the mare is in foal, she will need to have the stitched portion re-opened just prior to foaling. Because the opened portion will be allowing the passage of air (and bacteria) again into the vagina, the re-opening wants to be done as close as possible to foaling and it wants repairing as soon as possible after foaling, preferably the next morning.
We do offer a scheme or all-in-one fee for insemination with either Frozen or Chilled AI for mares coming into the clinic. There are certain criteria that need to be satisfied for your mare to qualify for the sheme package, and those criteria vary according to the type of semen insemination being used. To check if your mare qualifies for the scheme you will need to ring the clinic and speak to one of the stud vets. Even if your mare doesn’t qualify for the scheme, we will still accept her for any form of semen insemination but all procedures will be charged on an individual basis .
The current prices for the scheme packages are:
Fresh of Chilled Semen insemination:
1st Cycle £ 160.65 plus VAT
2nd and subsequent cycles £139.23 plus VAT
Frozen Semen Insemination
1st Cycle £338.10 plus VAT
2nd and subsequent cycles £269.97 plus VAT
The scheme covers all procedures related to the insemination and grass livery while the mare is in the clinic. If the mare requires stabling, then an additional supplement will be added. It does not cover vaccinations or any other treatment not specifically required as part of the insemination procedure. use of Ovuplant as a lutenising agent will incur an additional surcharge.
If the mare conceives, the scheme fee includes up to three ultrasound pregnancy scans to be performed at 16 days, 25-28 days and 42 days of pregnancy. If the mare is to be scanned at a location other than the clinic, a visit fee will be levied.
If the mare is not-in foal at the 16 day scan ( or any subsequent scan) then a new cycle of inseminations would begin and the appropriate charge levied unless the owner elects not to continue with the process.
Acceptance on to the scheme package does not guarantee that subsequent insemination cycles will be also accepted under the scheme package system. At the discretion of our veterinary staff, mare’s requiring excessive amounts of veterinary input not considered acceptable under the terms of the scheme package may be refused the scheme package for subsequent insemination cycles, those would have to be paid for by charging individually for procedures used on the mare. However, once a mare has been accepted on to the scheme package, for a particular insemination cycle, that cycle will be completed in full under the terms of the scheme.
The clinic is a BEVA approved centre for artificial insemination using both chilled and frozen semen. Our clinic laboratory is also one of a few laboratories in the country accredited for CEM (contagious equine metritis organism). This is the preventative scheme, overseen by the Horserace Betting Levy Board, to make sure mares and stallions at stud are screened for the venereal diseases that can affect fertility.
Chilled Semen AI
Mares can be dealt with at home, at a boarding stud / stables or admitted to the clinic for insemination with chilled semen. The semen is sent from the relevant stud in a special insulated and chilled container usually for next day delivery or same day, in some instances. The semen has about a 48 hour shelf-life in the container but should be inseminated into the mare as soon as possible. Timing is important and the mare will be examined internally and semen ordered to try and ensure that insemination occurs within the 24 hours prior to ovulation of the follicle. Weekends and bank holidays can make the precise timing difficult. The sperm will live for anything from 12 to 48 hours after insemination, inside the mare. Pregnancy rates will be similar to those achieved by natural service.
Frozen Semen AI
Mares must be admitted to the clinic for insemination and the monitoring leading up to insemination. Once the semen has been thawed the sperm must be kept at a constant 37oC and inseminated immediately. The sperm only live for about 6 hours after thawing so the timing has to be very precisely co-ordinated with ovulation. This is done by closely monitoring the mare at increasingly frequent intervals, as ovulation approaches. Around the time of ovulation, examinations will be made every 2-4 hours. As soon as ovulation is identified, insemination is performed, immediately, often this is in the early hours of the morning. The semen is thawed in a water bath at 37oC and once thawed, which takes about 30 seconds, immediately inseminated using a pre-warmed catheter. To further increase the success rates we use deep uterine insemination, depositing the thawed sperm right next to the end of the fallopian tube, which contains the unfertilised “egg”. To be even more precise, an endoscope can be used to directly visualise the end of the fallopian tube and deposit the sperm directly onto it. This method can reduce the quantity of sperm required to achieve acceptable pregnancy rates, which maybe of advantage if the stallion concerned is dead and semen supplies limited. This endoscopic method is more complicated and expensive than deep uterine insemination.
Thawed sperm are more fragile than fresh or chilled sperm and therefore, not suitable for use in mares with a hostile uterine environment, such as mares at foal heat or older mares or mares prone to uterine infections.
Because of the expense and work involved in using frozen semen it is not recommended to use this technique in a maiden mare, it is advisable to ensure her fertility using natural service or chilled semen AI before embarking on a frozen semen insemination.
Routine Mare Work
The practice does the routine work at a number of local studs and can deal with any mare requiring reproductive examinations. Routine work would include swabbing mares prior to covering, mares should have a clitoral swab prior to natural service, this is looking for any of the venereal bacteria ( CEM, Klebsiella pneumoniae or Pseudomonas aeruginosa). Some studs will also require a blood sample to ensure the mare is negative for EVA (equine Viral Arteritis) and EIA (Equine Infectious Anaemia or “Swamp Fever”) using a Coggins Test.
A clitoral swab can be taken at any time in the same breeding season as the mare is to be covered and the EVA blood sample should be taken within 28 days of being initially covered.
It is strongly advisable that mares also have a cervical or endometrial swab. This swab can only be taken if the mare is in season. The cervical swab not only checks for the venereal bacteria but for the presence of any bacteria inside the uterus and for non-infectious inflammation. The swab should be taken in the first day or two of the in-season period, this allows some time to treat any problem before the mare goes out of season.
Checking the mare’s ovaries once she is in season allows the vet to estimate a likely timing of ovulation and aim towards the ideal situation of a single covering as close to the time of ovulation as possible. Each time a mare is covered an amount of dirt, debris and contamination is deposited into the uterus along with the sperm, therefore, to reduce the risk of an infection being set up, the number of coverings should be kept to a minimum. Also mares should have their vulval area cleaned with fresh water and their tail bandaged prior to covering to reduce any potential contamination. Disinfectants and soaps should not be used.
Internal examinations not only allow the ovaries and their follicles to be monitored, the uterus is examined for oedema, one of the indicators of how well in-season the mare is and also the presence of any free fluid in the uterus which is a warning sign for infections or inflammation of the inside of the uterus which will dramatically interfere with fertility.
Mares can be checked for ovulation, this is useful for knowing when ovulation occurred and it’s timing relative to the last covering, for identifying multiple ovulations and therefore, the mares more likely to have twin pregnancies and for the identification of post-covering uterine infections, which are one of the most common causes of reduced fertility.
Scanning for pregnancy
The identification of pregnancy is important for several reasons,
1. Obviously to identify the pregnancy and avoid the need to return to the stud or be covered again.
2. To identify multiple pregnancies and deal with the situation as early as possible.
3. To ensure the pregnancy is normal and growing at an appropriate rate.
4. Identify mares that suffer early loss of the pregnancy so that they may be returned to stud the same year if appropriate.
Scans should ideally be done at 16 –18 days after covering, again at 25-28 days after covering and a third time at 42 days after covering.
The 16-18 day scan is looking to identify a pregnancy and also the first opportunity to identify possible twin or multiple pregnancies. A twin pregnancy can be squeezed to remove it. Up to 18 days the pregnancies move freely within the uterus and can be manipulated apart to avoid traumatising the remaining pregnancy. After 18 days they implant into the wall of the uterus and cannot be moved, if twin pregnancies are identified after 18 days and they are close together, then attempts to squeeze one is likely to traumatise the other one which dramatically increases the chances of loosing that pregnancy also.
The 25-28 day scan is checking that any pregnancy seen at the first scan is still present and has grown at a normal rate. From 25 days, the pregnancy should contain a heartbeat which is visible on the scan, this is a good sign that the pregnancy is growing, normally and is viable. If no heartbeat is seen the mare should be re-scanned a few days later, if no heartbeat is seen and the pregnancy has not grown, at this stage, abortion should be considered. It is also an opportunity to look for any additional pregnancies that may be some days younger than the initial pregnancy and therefore may have been too small to identify at the first scan.
The 42 day scan is performed to check the pregnancy has grown and is healthy. Most early pregnancy loss occurs prior to 42 days, so if a pregnancy has survived to 42 days it stands a reasonable chance of making it to term. This scan is also a last chance to ensure there is only one pregnancy present.
Sexing
It is possible to identify the sex of the foetus between 60 and 65 days after covering. It is not easy to perform as specific views of the foetus are required and because the scan is performed through the rectum the vet is very limited in the movement available of the probe. If the foetus is lying in an accommodating plane it may be quite straight forward to get the necessary views, if it is not then it may be impossible. If time is not an option one can wait for the foetus to move but this may take upto an hour or more and most mares if not the vet and owners cannot wait that long. After 65 days the pregnancy gets too big and is often out of range of most trans-rectal scanners to get the necessary views.
Barren Mares
Should a mare go through a breeding season and not conceive, then some investigations should be performed to try and find out why, before she is left to go through the winter.
If she has only been covered by one stallion and has not conceived to him previously, it is always worth changing to another stallion. Genetic mis-matches leading to unviable pregnancies, which are lost in the first couple of weeks are thought to be very common. If a mare is covered three times by one stallion, without success and she conceives the first time with a different stallion, it does not prove there was a genetic mis-match between the initial pairing but strongly suggests it and it would not be sensible to try and repeat that initial pairing.
If a mare has not had a cervical swab during the season then this should be performed when she is next in-season. If no obvious reason is found thus far, then an endometrial biopsy should be taken. This is done when the mare is in season, an instrument is introduced through the cervix and a pinch of tissue is taken from the uterine lining. This is sent off to the laboratory for analysis. Depending on the laboratory findings a treatment protocol can be formulated. Once that treatment has been administered and sufficient time to allow the treatment to have it’s effect, the biopsy should be repeated to make sure it has had it’s desired effect.
If the biopsy does not produce a reason for the infertility, then an endoscope can be used to look at the entire inside of the uterus which may provide a diagnosis for the infertility.
Caslicks
This procedure still causes controversy today.
The mare’s vulva is designed to be an airtight seal to the vagina. As mares get older, have more foals or just aren’t very fit, their abdominal wall slackens. This means the abdominal contents, the guts, drop. Since the rectum and anus are attached to the guts, they get pulled forward, over the pelvis, which obviously can’t move. Since the vulva is also attached to the rectum, it too, moves upwards. In the original plans, the top of the vulva was supposed to be level with the brim of the pelvis. This situation allows the air-tight seal to work. However, if the vulva is pulled upwards, as described above, then the portion raised above the level of the pelvic brim, no longer acts as a seal and allows air into the vagina. Unfortunately air entering the vagina also brings bacteria with it. Bacteria in the vagina also get onto the cervix and when the cervix opens i.e when the mare is in season, the bacteria can get into the uterus.
To correct this abnormality, we can perform a Caslicks Operation. This means stitching the portion of the vulva that sits above the pelvic brim and returning the rest of the vulva to an air-tight seal. Once stitched, the skin edges heal and the actual suture material can be removed but if the mare is in foal, she will need to have the stitched portion re-opened just prior to foaling. Because the opened portion will be allowing the passage of air (and bacteria) again into the vagina, the re-opening wants to be done as close as possible to foaling and it wants repairing as soon as possible after foaling, preferably the next morning.
We do offer a scheme or all-in-one fee for insemination with either Frozen or Chilled AI for mares coming into the clinic. There are certain criteria that need to be satisfied for your mare to qualify for the sheme package, and those criteria vary according to the type of semen insemination being used. To check if your mare qualifies for the scheme you will need to ring the clinic and speak to one of the stud vets. Even if your mare doesn’t qualify for the scheme, we will still accept her for any form of semen insemination but all procedures will be charged on an individual basis .
The current prices for the scheme packages are:
Fresh of Chilled Semen insemination:
1st Cycle £ 160.65 plus VAT
2nd and subsequent cycles £139.23 plus VAT
Frozen Semen Insemination
1st Cycle £338.10 plus VAT
2nd and subsequent cycles £269.97 plus VAT
The scheme covers all procedures related to the insemination and grass livery while the mare is in the clinic. If the mare requires stabling, then an additional supplement will be added. It does not cover vaccinations or any other treatment not specifically required as part of the insemination procedure. use of Ovuplant as a lutenising agent will incur an additional surcharge.
If the mare conceives, the scheme fee includes up to three ultrasound pregnancy scans to be performed at 16 days, 25-28 days and 42 days of pregnancy. If the mare is to be scanned at a location other than the clinic, a visit fee will be levied.
If the mare is not-in foal at the 16 day scan ( or any subsequent scan) then a new cycle of inseminations would begin and the appropriate charge levied unless the owner elects not to continue with the process.
Acceptance on to the scheme package does not guarantee that subsequent insemination cycles will be also accepted under the scheme package system. At the discretion of our veterinary staff, mare’s requiring excessive amounts of veterinary input not considered acceptable under the terms of the scheme package may be refused the scheme package for subsequent insemination cycles, those would have to be paid for by charging individually for procedures used on the mare. However, once a mare has been accepted on to the scheme package, for a particular insemination cycle, that cycle will be completed in full under the terms of the scheme.
