Ovulation Timing and Breeding Management
The most common cause of infertility in the bitch is inappropriately timed breeding.
Litter size and pregnancy rate is maximized if the bitch is bred within her most fertile window, which is 2-6
days after ovulation. In many bitches, sexual receptivity (“flagging” for the male and standing to be
mounted) does not coincide with peak fertility period. Not breeding too early or too often also helps with
optimal use of a male in high demand. Additional benefits of ovulation timing are prediction of parturition
date, which is important in bitches with a singleton pregnancy or in bitches that will require caesarean
Ovulation timing includes one or a combination of several techniques: vaginal cytology, vaginoscopy,
serum progesterone testing and in some cases serum luteinizing hormone (LH) assay. We recommend to
start with ovulation timing on day 5-7 of the heat cycle if the cycle length is average (approx. three
weeks), and sooner if the cycle is short (2 weeks or less). In most cases, blood collection for
progesterone is recommended every 2-3 days until ovulation can be confirmed. Even if 80% of bitches
will most likely ovulate on day 10 or 12, it is considered normal for a bitch to ovulate on day 4 or 24 of her
A Common misconception is that there are fixed progesterone values around the luteinizing hormone
peak as well as ovulation. Even if there is a common trend of progesterone values to be between 4 and
10 ng/ml (12.6 and 31.4 nmol/L) at ovulation, it varies dramatically between bitches and therefore it is
important to know a bitch's baseline before making decision about her values at ovulation.
At Graham Animal Hospital, progesterone values are available on the same day, within 2 hours of blood
This type of breeding is considered best for young, fertile females and males known to
have good fertility, as the sperm cells need to spend some time in the bitch's reproductive tract before
they are capable of fertilization (undergo a process called capacitation). The type of breeding is started
early and performed every other day (most commonly on days 1, 3 and 5 after ovulation). The biggest
advantage of natural breeding is the low cost and it is probably the most efficient way to get maximal
number of sperm cells into the bitch's reproductive tract. Main disadvantages of natural breedings are the
lack of semen evaluation and proof of ejaculation as well as the need for the male and female to be on
the same premises. Brucellosis testing is recommended for all dogs bred naturally, less because of high risk of disease, but more to avoid legalities in the rare occurrence of infection.
Vaginal Artificial Insemination (AI).
This type of breeding is ideal when the male is either inexperienced
or unable to achieve a tie for whatever reason. The biggest advantage of having an artificial insemination
is that a full analysis of the semen can be performed, ensuring that the sample is adequate in
concentration (with minimal prostatic fluid), motility and free of abnormalities. Vaginal AI lowers the risk of
injury if unfamiliar dogs are used. An insemination pipette is inserted and gently threaded forward until
resistance is met, indicating that the pipette has reached the narrow part of the vagina. At this point, a
syringe containing the semen sample is connected to the pipette and deposited slowly into the vagina.
When the entire sample has been injected, the pipette is removed, the bitch's hind end may be kept
elevated for about 10 minutes and a light feathering can be performed for about 5 minutes to encourage
vaginal contractions to transport the semen through the cervix into the uterus. The vaginal AI with fresh
semen is generally performed on the same days as natural breeding. With fresh chilled semen, as
capacitation time is shorter, we prefer to inseminate day 2 and 4 after ovulation.
Transcervical Artificial Insemination (TCAI).
The biggest advantage of TCAI is that the bitch does not
require general anesthesia for it to be performed and it does deliver semen into the uterine lumen, as in
surgical insemination. For TCAI, the bitch is fully awake and in a standing position. During the procedure,
an endoscope is inserted vaginally and pushed through the vaginal canal towards the cervical opening
(also called external os). A small catheter is threaded directly into the cervical opening and the semen
sample is injected through the catheter. This procedure can be observed on screen by all participants and
can take from 3-45 minutes, 5 minutes on average. Having a concentrated semen sample injected
directly into the uterus increases the number of spermatozoa that will reach the eggs, thus increasing the
chances of conception. In the rare instance that the catheter cannot pass through the cervical opening;
whether it is due to anatomical abnormality or position of the cervix, a surgical insemination is
recommended. The main disadvantage of TCAI over vaginal AI is cost because of the specialty
equipment and skills necessary. TCAI can be used for fresh, chilled or frozen semen and is
recommended for bitches with fertility problems, as well as in cases where semen quality is impaired, like
frozen semen and semen from subfertile studs.
Surgical Artificial Insemination (SAI).
This type of insemination is performed under general anesthetic.
A small abdominal incision is made and the uterus is exteriorized. At this point, the veterinarian can
examine the uterus for any obvious abnormalities (e.g. cysts and adhesions). A small needle with a
catheter tip is inserted close to the tip of one horn and half of the semen sample is injected directly into
the uterine lumen. This procedure is repeated with the second horn. The uterus is then replaced into the
abdomen and the incision is routinely sutured (3 layers) with a absorbable suture material. Generally the
procedure takes from 30 to 45 minutes. A surgical insemination is the best option for bitches that have
long standing fertility problems as well as in cases where semen quality is impaired, like frozen semen
and semen from subfertile males. Benefits of this procedure include: evaluation of the uterus and ability to
place the semen exactly where it needs to be while evenly distributing it through each horn. Anecdotally,
SAI has the highest conception rate of all of the forms of AI; however, it is the most costly and it does
expose the bitch to a full general anesthetic. SAI is only performed once, in most cases 3 or 4 days post
ovulation if frozen semen is used, however, if multiple inseminations are desired , it can be used together
with TCAI on consecutive days.
Pregnancy Ultrasound (U/S)
. Pregnancy ultrasound confirms pregnancy in mid-gestation, therefore
answering questions of potential false pregnancy, as well as providing us with information about litter size
and due date. Fetal viability can be assessed, and if multiple fetal absorption sites are observed,
diagnosing and treatment for hypoluteoidism (insufficient levels of pregnancy sustaining hormone
progesterone) can be initiated. Ultrasonography also helps us to early diagnose pyometra and
mucometra, helping us initiate treatment early. We recommend to perform pregnancy ultrasound on days
25-28 post breeding. If performed later, accurate staging of pregnancy and fetal count becomes difficult.
There is a common misconception that ultrasound waves can be dangerous to developing embryos,
however, in research settings, bitches that were ultrasounded daily for the length of the entire pregnancy
delivered good size litters with healthy pups. The procedure is short, and delivers valuable information,
therefore, like in human medicine, the stand is that the benefits by far outweigh the risks. A printed copy
of an image is available for the owner for no extra fee.
Pregnancy x-ray (digital)
. A pregnancy x-ray is performed during the last week of pregnancy to
determine number of the fetuses, so the owners can be sure when the whelping is completed. For the
procedure, the bitch is lifted onto an x-ray table and laid on her side, the radiograph of her abdomen is
taken and developed directly after. This procedure generally takes 5-10 minutes. A copy of the x-ray can
either be emailed or burned onto a CD for a minimal fee.
At Graham Animal Hospital we offer advice on what is expected during uncomplicated whelping.
Staff on call is prepared to provide both surgical and medical interventions if there is a problem
(dystocia). Prediction of parturition date is possible early in heat cycle via progesterone testing, in
mid-pregnancy via ultrasonography and at term using a combination of tests. This becomes very
important when staging the bitch for an elective cesarean section.
We also offer medical treatment for pyometra using Alizine (please discuss the possibility of use of this drug with staff members). The same drug can be effectively used for early termination of unwanted pregnancy.
Male Breeding Soundness Evaluation (BSE)
A complete fertility evaluation of the stud dog routinely involves history, brief physical examination,
semen collection and evaluation and examination of the prostate. To obtain the most representative
sample, semen collection should be performed in the presence of an teaser bitch in heat whenever
possible. Canine semen is ejaculated in 3 fractions: 1) pre-sperm fraction – which arises from the
prostate and urethral glands, thought to cleanse the urethra of contaminants prior to ejaculation; 2)
sperm-rich – which arises from the epididymal sperm storage and contains high numbers of sperm cells;
3) prostatic fluid – which provides volume to the ejaculate, which during a natural tie assists in pushing
the sperm through the cervix into the uterus. There is no minimal accepted semen volume since it
depends on how well fractionated the ejaculate is and how much of each of the fractions is collected.
is assessed by placing a drop of raw semen on a pre-warmed microscope slide and
applying a pre-warmed coverslip. A normal ejaculate contains a minimum of 70% progressively motile
sperm. Semen concentration
is measured in millions of spermatozoa per milliliter of semen. On average
acceptable numbers of total sperm/ejaculate will be from 200 – 300 million for toy breeds; from 200 – 500
million for small breeds; from 400 – 800 million for medium breeds; from 500 million – 1.5 billion for large
breeds; and from 600 million – 2 billion for giant breeds. At least one hundred sperm cells should be
examined for evaluation of morphology
for normal shape and structure. A normal ejaculate contains
>70% morphologically normal sperm. A semen swab for bacterial culture may be submitted to the
laboratory if high numbers of white blood cells are present in the ejaculate and infection is suspected. In
certain cases, where fertility issues are evident based on pregnancy rates but are not evident based on
normal fertility examination, advanced testing may be dictated. This may include hormonal evaluation,
karyotyping, testicular aspiration or biopsy and other tests.
Males should be evaluated for reproductive function prior to their first attempt at breeding, if it has been
several months or years between breedings, or if fertility begins to decline or is questionable. In some
cases, a routine reproductive examination will suffice, but in others, advanced diagnostics may be
Normal and abnormal semen morphology. Adapted from Nelson et al., Small Animal Internal Medicine, Mosby, 2003
Semen processing options
Fresh chilled semen.
Fresh chilled semen is a great option when geographic distance between dam and
sire is a problem. Males with excellent semen quality are the best candidates. For the shipment, the
semen is collected, evaluated and an extender is added to provide the spermatozoa with the nutrition
they need to survive. The sample is then packaged in a special shipping container that keeps semen at
approximately 4-5 °C (degrees Celsius) for 24-48 hours. Containers most frequently are shipped via FedEx to many locations in Canada and internationally. It is very important that ovulation timing is performed on the bitch and that the semen is sent at the ideal time to not leave the semen sitting idle when it arrives at its destination. It may be somewhat complicated to make shipments over a weekend due to increased cost of Saturday deliveries and no shipments made on Sundays. We recommend to perform a test chill prior to shipping semen to determine semen viability and compatibility with any given extender.
. Collection, freezing and a long term storage of semen can alleviate some of the stresses
associated with a popular stud. For inexperienced stud dogs, collection with the presence of a teaser
bitch is beneficial, as the number and quality of the sperm cells depends greatly on ease of collection.
After collection, the sample is analyzed for morphological abnormalities, total sperm cell number and
motility. Ideally, the sperm before freezing should have 85-90% progressive motility and >75% of sperm
cells should be morphologically normal. Graham Animal Hospital is a recognized member of ICSB
(International Canine Semen Bank). When the freezing process is complete, a sample pellet is thawed to
ensure that the thaw motility of the semen is adequate. Semen is stored in vials containing pellets,
submerged in liquid nitrogen directly at our facility. Benefits of frozen semen include the ability to ship
practically anywhere in the world and currently this is the only practical method to preserve stud dog's
DNA indefinitely. Frozen semen is believed to last as long as it is kept submerged in liquid nitrogen and is
not expected to deteriorate over the years; however, like with all living organisms, nothing can be
guaranteed 100%. As the numbers and longevity of frozen sperm cells are lower than in fresh or fresh
chilled samples, frozen semen is only recommended to be inseminated via TCAI or SAI. Obviously, the
one disadvantage of frozen semen is that it can be costly for the initial freezing but is very reasonable
when it comes to subsequent freezings and storage fees.
It is highly recommended to perform semen collection and freezing early in the stud’s life (i.e. 2.5-4 years) in attempt to obtain the best sample possible. When the dog is presented later in life, even if he is still achieving adequate litter sizes by natural breedings, semen quality is in most cases already declining due to age-related testicular degeneration and therefore post-thaw results as well as expected fertilizing ability is poor.
At Graham Animal Hospital, we perform routine OFA certifications, DNA test submissions for
breed-specific disease screening, puppy wellness exams/vaccinations, microchip insertions and
numerous other services. Breeder discount is available.
Reproductive Services Ovulation Timing and Breeding Management Ovulation Timing. The most common cause of infertility in the bitch is inappropriately timed breeding. Litter size and pregnancy rate is maximized if the bitch is bred within her most fertile window, which is 2-6 days after ovulation. In many bitches, sexual receptivity (“flagging” for the male and standing
Penicillinase Solution Composition and concentration The Penicillinase solution contains Storage and use by date The Penicillinase solution can be stored at 6 – 10 °C, until the mentioned date on the packing (for at least 6 weeks). In the case of contamination the solution may be rendered unusable or may lead to incorrect results. The solution must therefore always be kept cl