Stud Medicine
Stud medicine encompasses all veterinary work required for mares, stallions and foals in their early (neonatal) life. We offer a complete stud medicine service to help you from the time you start thinking about breeding until after your foal is born.
The Breeding Season
Horses are known as seasonal or long-day breeders, i.e. they only cycle during a set period of the year. The increase in day length at the beginning of spring time (February/March) stimulates hormonal changes starting the oestrus cycle. Just as the increasing day length initiates the hormonal activity, the shortening day length in autumn time reduces it and mares will subsequently stop cycling around October or November.
Because it is the amount of daylight that is responsible for the onset of the mares’ seasons; it is possible to advance the breeding season artificially, commonly done in the racehorse breeding industry. This can be done by using a methodical lighting regime.
Interestingly, the stallion’s reproductive function does not stop in the winter however daily sperm production and volume, hormonal concentrations and libido are much greater in the true breeding season.
Mares will come “into season” approximately every 21 days. The oestrus period (“season”) lasts 5-7 days, in which they will exhibit overt signs of receptivity towards a stallion. These signs vary greatly between mares. The behavioural signs will reduce as ovulation approaches and oestrus ends approximately 24 hours ovulation occurs.
Pre-breeding Assessment & Investigation of the Barren or Susceptible Mare
Prior to breeding from your mare it advisable to have a pre-breeding assessment performed. Many studs will require certification to prove the mare is free from CEM (Contagious Equine Metritis) and EVA (Equine Viral Arteritis). This is very straightforward and involves taking a clitoral swab (CEM) and a blood sample (EVA). We recommend that your mare has a clinical and ultrasonographic assessment of the reproductive tract (vulva, vestibule, cervix, uterus and ovaries) prior to the start of breeding. This can be done at the same time as the swab and/or blood sample. This identifies potential problems, confirms the mare is cycling and at which stage of the cycle she is in. This is especially important if your mare needs to be taken to stud to be covered, but does not demonstrate overt oestrus behaviour.
We provide a comprehensive service for the investigation of susceptible (those which may have had previous reproductive problems) or barren (those which failed to conceive) mares. Additional techniques used in these cases include endometrial swabs and biopsies and endoscopy of the uterine tract (videohysteroscopy).
Pre-breeding Assessment & Subfertility Investigation in Stallions
Assessment of the stallion should take place as far in advance of the breeding season as possible especially if it the first breeding season. The assessment includes a full general clinical examination, observation of libido and mating ability and detection of venereal infectious diseases (including CEM and EVA), giving an insight into semen quality and quantity.
Artificial Insemination
Cliffe Equine Clinic is a registered British Equine Veterinary Association (BEVA) approved centre for fresh, chilled and frozen semen artificial insemination (AI).
Most centres will still inseminate fresh or chilled semen into the uterine body. We now perform all types of inseminations using the deep uterine insemination (DUI) technique. This is where a long, flexible and atraumatic catheter is passed up to the tip of the horn on the side with the ovulatory follicle on it and the semen is deposited right at the entrance of the oviduct. This technique has improved conception rates, especially in mares that have failed to conceive previously due to fluid retention in the uterus, or if the semen used has low numbers of sperm in it.
All inclusive packages are available for AI. The package starts when your mare is in season and includes:
• Visits or livery at the clinic
• Sedation if required
• All rectal and ultrasound examinations throughout each cycle
• Liaison with the stud
• Storage of semen (frozen)
• Ovulation induction agents
• The insemination procedure
• Assessment of the semen
• Post-ovulatory scan & wash out of the uterus, including all routine drugs used
• The first pregnancy ultrasound scan at 14-16 days post insemination
The packages do NOT include:
• Pre-breeding assessment of the mare / stallion
• CEM swabs / EVA blood tests
• Visit and drugs used to manipulate the oestrus cycle
• The second pregnancy ultrasound scan at 30 days post insemination
Fresh or chilled AI performed at Cliffe Equine Clinic: £250 + VAT
Fresh or chilled AI performed at your yard: £350 + VAT
Frozen AI (only performed at Cliffe Equine Clinic): £300 + VAT
Pregnancy Diagnosis and Twin Management
Pregnancy diagnosis is most commonly and reliably performed using ultrasound scanner. This allows for the detection of an embryo early on in pregnancy. It is advisable to have two examinations performed – the first scan at 15 days after covering/insemination; and the second at 30 days.
The first scan not only diagnoses a pregnancy but also allows us to detect and treat twins. Should twins be present one of the embryos should be “crushed” or “squeezed” leaving only one embryo. If twins are left it is most likely the mare will either resorb the pregnancy or one foetus with die during pregnancy causing abortion resulting in the loss of both twins. It is easier and safer to reduce the pregnancy to one before day 17. On day 17 the embryos will become attached to the uterus wall and the chance of both embryos being damaged and the pregnancy lost during this procedure is greater.
The second scan will confirm the embryo is still present, is growing and is alive by the presence of a foetal heart beat.
We also offer a late scan within 4 weeks of the expected foaling date. This scan assesses the foetal heart beat and health by monitoring the foal’s movement. The position of the foal within the uterus does not change between now and foaling. If the foal is seen to be in a breach position precautionary arrangements may be made should a caesarean procedure be required.
Post Foaling Examinations
An examination of the mare and newborn (neonatal) foal should be undertaken within 6 hours of foaling. The mare should expel the placenta (cleanse) with this period. This should be kept to show the vet at the examination to check it is complete. Should some or the entire placenta be retained for longer than this period the mare must be seen as an emergency.
The foal should be standing up a sucking from the mare within 2-3 hours of birth. If there is a problem with the foal standing or sucking its immunity maybe affected. A blood sample can be taken at 24 hours of age to measure IgG levels in the blood to determine foal’s immune status. Tetanus and antibiotic protection is provided for the foal where needed.
More information on foals, foaling and failure of passive transfer are available on our fact sheets. (LINK)
Further Advice
We are happy to discuss specific cases or requirements in detail with you and provide advice on other topics such as: suitability for breeding; managing the difficult “in season” mare and problems during pregnancy. For advice on stud medicine concerns please ring the clinic to speak with Karl Holliman or Imogen Silhan-Sutton.
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