- Catley Cross Veterinary Clinic

Stud Medicine and Artificial Insemination
Information and prices 2015
Pre-breeding Exam
A.I. packages
Pregnancy Diagnosis
Foal check
A. ‘Stud medicine’ is a veterinary subject area concerning the reproductive and medical
management of mares, stallions and foals. In the U.K. there is an equine breeding
season in the spring and summer months as mares are ‘long-day breeders’ – that is,
this is when they have regular oestrous cycles or ‘seasons’ when they are able to be
bred. The thoroughbred breeding season is artificially brought forward to earlier in
the year by managemental, hormonal and environmental manipulation.
A mare comes into season roughly every three weeks, with each oestrous period
lasting about five days. Ovulation occurs about 24 hours before the end of
behavioural oestrous. The mare will continue regular cycling until around October
when the ovaries become progressively less active and eventually reproductive
cycling stops completely over the winter months – so called ‘anoestrous’. As day
length increases in the spring mares start to show erratic oestrous behaviour with
prolonged periods of apparently being in season but without any ovulation occurring.
This ‘transitional’ stage continues until the hormones involved reach sufficient levels
that ovulation eventually occurs and the mare goes on to cycle on a regular basis
until the autumn.
Stallions are also affected by the seasons, for instance, sperm production reaches a
maximum between May and July.
B. Artificial insemination involves the use of fresh, chilled or frozen semen. There are
advantages and disadvantages to breeding mares using artificial insemination
compared with using a ‘natural cover’. From a veterinary perspective the main
difference is that the timing of insemination has to be a lot closer to the point of
ovulation when using artificial techniques – particularly so for chilled and even more
so for frozen semen. This invariably requires the use of repeated physical and
ultrasonographic examinations of the mare’s reproductive organs in order to get the
timing ‘right’.
From an owner’s perspective there are some general issues such as the mare’s age
and fertility, mare safety and the higher costs of A.I. which need to be considered.
With particular reference to chilled semen this technique generally produces higher
conception rates and requires less intensive gynaecological work. Even so it must
be inseminated within 48 hours of collection. It is essential to find out what you are
paying for when buying semen – e.g. how many doses of semen will you get and are
there any additional transport costs? Semen coming from abroad must come with
the relevant paperwork. Semen transported without an official export health
certificate from the country of origin cannot be legally inseminated into U.K. mares. It
is important to check that the stallion’s semen chills and travels well (as not all do)
and find out which days of the week the stallion is collected from and how much
notice you will have to give in order for the semen to be collected and sent.
Frozen semen can be collected from stallions anywhere in the world and sent to the
mare owner well in advance, avoiding potential late delivery. It is important that it is
ordered from a reputable stud so ask for details of semen quality and post-thaw
motility (some stallion’s semen does not freeze well). Again it is important to know
what you are paying for and how many doses. Semen handled badly during
transport may not be viable. Appropriate export health certification accompanying
the semen is also vital.
C. It is recommended all mares which are to be bred have a pre-breeding examination
beforehand. This involves a physical and ultrasonographic examination of the
ovaries, uterus and cervix and testing the mare for venereally transmitted infections.
These tests may involve a blood sample for Equine Viral Arteritis (EVA) and Equine
Infectious Anaemia (EIA) and always involve a clitoral swab for Contagious Equine
Metritis (CEM) and two other bacteria causing venereal disease. If any problems are
identified at this stage they can potentially be dealt with before the main breeding
season starts. It can take 7 -10 days to get the results so please allow enough time
for this. This examination is especially important for maiden mares, barren mares
and older mares (13 years plus). The autumn is a good time for investigating
potential fertility problems in ‘barren’ mares, that is, those that have failed to conceive
in the previous stud season. Techniques used include uterine swabs and biopsies,
ultrasonography, hormone testing and endoscopic examination of the uterus.
Pre-breeding assessment of stallions is also possible and can include a physical
examination, observation of libido and mating ability and swabbing for venereal
D. Catley Cross Veterinary Clinic offers packages for mares which are to be bred with
artificial insemination. Packages are only available for mares boarding at the
Practice for their reproductive work. Catley Cross Veterinary Clinic is a BEVA
Approved Centre for fresh, chilled and frozen artificial insemination and our vets and
nurses are familiar with the latest techniques and ideas in the field of equine
reproduction. Before entry into a packaged AI program a mare has to be confirmed
she is cycling normally within a month of the planned breeding. This can be done at
the same time as a pre-breeding examination and may require the use of a blood
sample to measure progesterone levels.
Packages include all routine work, grass livery and routine drugs relevant to
breeding. Some mares are not suitable for a package, these include maiden mares
14 years and older and those with a poor breeding record. Treatment of ovarian or
uterine problems or non-cycling mares is not included. All work must be carried out
at Catley Cross. Reproductive scans carried out off-site will incur a visit charge and
charge for the scan.
Includes: scans prior to insemination, prostaglandin injections (if required), ovulation
hormone, insemination, liason with stud, semen evaluation, post-insemination
oxytocin injections, post-insemination uterine flushing (if required), post-insemination
scans and pregnancy scans at 15 days and 25 days after ovulation.
Excludes: clitoral and endometrial swabs, EVA/EIA blood sample, progesterone
blood samples, laboratory fees, sedation, drugs and treatments for complications e.g.
antibiotics and supplement for stabled livery
All prices are subject to VAT.
Chilled per cycle price:
Frozen per cycle price:
Other relevant prices:
Stabled livery supplement:
Pre-breeding exam
Lab fees per swab (approx.):
Lab fees per progesterone test (approx.):
Postage for samples (approx.):
Breeding work carried out at home premises
We are very happy to carry out stud work at the home premises, where the work will
be charged out on an individual basis, as per our standard charges.
E. Pregnancy diagnosis and twin management
It is usual for a mare to have her first scan for pregnancy 15 or 16 days post-covering
or insemination. This allows early detection of twins, which if left untreated, usually
leads to the abortion of both foetuses. Treatment of twins at this early stage is
possible and involves crushing one of the early embryos, leaving the other to go on
and develop normally. This type of treatment is risky beyond day 18 after which both
embryos are often fatally damaged during any attempted crushing.
In the normal situation a second ultrasound scan for pregnancy is essential at 25-30
days post-ovulation. This allows confirmation of a foetal heartbeat and re-checks the
mare for the presence of twin embryos.
Other useful times to scan during pregnancy are at around 42 days to check general
development and between 60 – 65 days in order to check the sex of the foetus. This
is a specialist procedure and Craig is still gaining experience in this technique. The
foetal sex scan is therefore being offered free of charge if done at the same time as
other work on the premises. Scans to assess the well-being of the late-term foetus
can also be carried out in the last month or two of pregnancy.
F. Post-foaling Examinations
It is recommended the mare and newborn foal are examined the following day after
birth. The mare is checked for tears and the placenta is examined for completeness
and any abnormality. The foal should have been sucking from 2-3 hours after birth
and a blood sample taken from 12 hours after first suck can confirm adequate
transfer of immunity via the colostrums. A physical examination of the foal is able to
confirm all is well or may allow the vet to point out things which need monitoring or
Please direct any other enquiries to either Craig Rutland or Karen Church via the
Practice office.