Theriogenology Service (Reproduction and Fertility)

Theriogenology Service

Theriogenology Service (Reproduction and Fertility)

Welcome to the Theriogenology Service at the UC Davis Veterinary Medical Teaching Hospital, where we provide a wide array of canine and feline reproductive offerings, including ovulation timing, breeding management, artificial insemination, transcervical insemination, pregnancy evaluation, obstetrics, and pre-breeding and infertility evaluations. The service also works with patients regarding disorders of the reproductive tract (vaginitis, prostate disorders, mammary disorders) in both intact and spayed or neutered animals. Pediatric patients with congenital disorders may also be evaluated on this service. Often working in coordination with the hospital’s Genetics Service, the Theriogenology Service can also provide genetic screening tests for breeding animals (OFA orthopedics, thyroid, breed-specific genetic conditions, etc.), as well as counsel regarding their importance to the health of the animal or breeding program.

Clinical Activities and Procedures

Reproductive Examination

A complete examination of the reproductive organs, as well as an overall examination of physical health, is performed on all of our patients during their initial visit. Physical exam findings can help us to support the presence of good fertility, as well as give us clues as to possible causes for infertility in female and male dogs. At most appointments, a resident and faculty clinician will evaluate your pet and provide recommendations. Occasionally, we will have students or other visiting staff present during appointments, who may observe the procedures with your permission.

If your dog is here for subsequent ovulation timing appointments, a technician will acquire the samples for doctors to evaluate subsequently. Generally, it will involve drawing blood for progesterone, evaluation of a vaginal swab on a microscope slide, and looking at the vaginal wall with a small vaginoscope. All of these parameters are important in evaluating her cycle. After they have been reviewed and any blood work returned, a plan will be recommended by the veterinarian working with you via the contact method you prefer.

Consultation for Breeding Management

During your appointment, a detailed discussion of the dog’s or cat’s health history will be acquired – both general health and reproductive health. Each animal and breeding program is individual in its potential needs and goals, and we will do our best to accommodate these.

For both female and male dogs in your program, it is a good idea to keep a journal of records including vaccine history, deworming (or fecal exam) history, details of their diet, medications they have been on, and when they’ve been traveling to shows and other events. For female dogs, any attempts at breeding should be documented, as well as outcomes of pregnancy. You should also keep track of when she has been in estrus, and how long those estrus signs are seen. For male dogs, any previous collections and evaluations should be catalogued to monitor for trends. Keep track of his success rates using different methods (natural, artificial insemination, etc.). 

Genetic Screening Tests

Any animal that has a future as a breeding dog should be assessed for diseases that affect his or her breed. Some of these tests can be performed at a young age (BAER testing for hearing, DNA test, etc.), while others require the dog to be a young adult before evaluation is accepted (OFA orthopedics, OFA cardio, CERF eye testing, etc.). Your breed’s national club should have information on their website regarding the diseases that they recommend screening for in breeding animals. Also, is an excellent resource for breed-specific recommendations in dogs.

Tests that the Theriogenology Service can assist you with include OFA orthopedic evaluation (hips, elbows, or shoulders), OFA patella evaluation, OFA dentition, and OFA thyroid. We also can acquire samples for additional DNA tests that are appropriate for certain breeds and submit the samples to the appropriate laboratories. Any veterinarian can complete these tests, but many do not have experience in sending samples properly, and positioning correctly for orthopedic radiographs.

Evaluation of some diseases requires a consultation with a specialist. Our Cardiology, Neurology, and Ophthalmology Services regularly see our breeding patients for pre-breeding screening testing, including OFA cardiology evaluation, BAER hearing testing, and CERF or OFA eye testing, respectively. Please consult directly with those services if you require those tests. They can all be reached through the Small Animal Clinic at 530-752-1393.

Female Procedures

Ovulation Timing

Ovulation timing combines several techniques to determine a window of fertility to breed within during a heat cycle. Accurate timing will optimize her conception rate and litter size.

Three main diagnostics are used to determine this when your dog is here for this service:

  • Vaginal cytology is used to evaluate the cells of the vagina on a slide under a microscope. A long cotton tipped swab is used to obtain cells in the vagina, and a special stain is used to see the outlines of the cells. This modality helps us determine whether she is approaching her fertile window, and also indicate to us when she is too far along in the cycle to breed successfully.
  • Progesterone testing is used to estimate the time of ovulation, and subsequent fertile breeding days. This involves drawing a blood sample, which is submitted to our in-house laboratory. Usually we receive results within 2-3 hours of submission.
  • Vaginoscopy, or looking at the vaginal wall with a vaginoscope, is another component of our estimation of her fertile window. The vaginal wall will look “crenulated” (dehydrated) during her progesterone rise, and become maximally so during her most fertile days.

Generally, we will begin seeing dogs for ovulation timing on around the 5th day after heat for a cycle in which the owners wish to breed her. Every 2-3 days we will evaluate her, until she reaches the optimal window for breeding.


  • Assisted Natural Breeding: This method is great for reproductively healthy patients that just need a bit of “help.” Sometimes the experience or size different of the animals can affect their ability to breed unassisted. This can oftentimes be accomplished at home by an experienced breeder, but some owners prefer veterinary assistance.
  • Vaginal Artificial Insemination: This method simulates the deposition of semen in the cranial vagina, as in a natural breeding. This is ideal for a male and female of good fertility, and is appropriate for fresh collected or fresh chilled (shipped) semen.
  • Trans-cervical Insemination: This method will place the semen into the uterus, resulting in the highest conception results for the animal. A small endoscope with a camera is guided into the standing dog, and her cervix is catheterized. The semen is deposited through the catheter into the uterus. This method is appropriate for subfertile dogs and frozen semen, but can be utilized to optimize success in our fertile patients as well.
  • Surgical Insemination: This method is equivalent to trans-cervical in the location of semen placement. It is a full surgical event, with general anesthesia, shaving of the abdominal area, and incision into the abdomen. The semen is placed into the uterus using a small catheter. Although this procedure can carry success, in most cases we do not recommend the surgical option for insemination due to its invasiveness.

Pregnancy Diagnosis and Monitoring

Pregnancy diagnosis for our canine patients can be performed at around 28 days after the LH surge, which is a day determined during ovulation timing. If ovulation timing was not performed, we recommend checking her 28 days post breeding or AI. This initial evaluation will confirm her pregnant, and allow us to see heart beats and overall fetal health. This is not an ideal way to count the number of fetuses, but we can often give an estimation to help to guide you in her care in the latter part of her pregnancy.

Pregnancy radiographs can also be diagnostic in the few weeks of her pregnancy. The most common request for this procedure is for a “puppy count.” We also recommend pregnancy x-ray for evaluating the size and development of the fetuses, and make sure they are not too large to be delivered naturally. For best evaluation of size, we recommend radiographs 3-5 days prior to her due date based on ovulation timing.

Additional monitoring can be applied to special animals that have difficulty carrying their pregnancy. An at-home uterine monitoring system can be implemented for regular monitoring. In some cases, we recommend serial progesterone tests to ensure progesterone levels are adequate. Ultrasound can be utilized throughout of pregnancy in order to evaluate fetal health.

Planned and Emergent C-sections

C-sections can be elective or emergency. Most commonly, the need for an emergency C-section is due to oversized puppies, very small or very large litters, or uterine inertia.

Elective C-sections are commonly appropriate for brachycephalic breeds, and dogs with a familial history of complicated deliveries. With proper ovulation timing and daily evaluation when she is nearing her due date, C-sections can be a safe alternative to natural delivery.

Emergency C-sections can be performed during regular hours or after hours. Our team, as well as the surgery and anesthesia teams, will work swiftly to perform the procedure to optimize the viability of her litter and her health.

Male Procedures

Semen Collection

For dogs, semen collection is routinely performed as a regular evaluation tool for the stud dog. Manual stimulation for most animals is a successful means of acquiring a sample. The semen can be evaluated for sperm motility (motion), speed, morphology (structure), and other parameters. If the patient has a negative brucella test within six months of the appointment, a teaser female can be provided if requested.

For cats, general anesthesia is required unless the animal has been specially trained to collect into an artificial vagina. For most of our patients, after anesthesia has been administered, we can stimulate the ejaculation rectally with a probe to collect a sample.

Semen Shipments

Many of our stud dog patients are on request for shipment of chilled semen to a bitch in another location. A collection is performed, and the semen is diluted in a commercial semen extender for transport via FedEx. The shipments are generally sent overnight to the veterinarian of the female to receive the semen. Evaluation is performed prior to packaging, and is provided for both the stud and bitch owner.

Semen Freezing

Semen freezing can be performed here, and we can store semen on site long-term for use or later shipment. For elective freezing of healthy animals, one day per month is designated. Freezing of semen can be performed if there is more emergent need an alternate day. As with the general semen evaluation appointments, the semen will be collected and evaluated for quality, and if deemed of good quality, could be diluted and chilled in special extenders prior to freezing. We evaluate all samples after freezing, as they vary in quality after the processing. Frozen semen is predicted to last hundreds of years if maintained properly. Successful litters have been produced in the dog after 40 years of cryopreservation.

The freezing process from start to finish takes 4-6 hours, so we schedule all semen freeze appointments for the day in the morning. We recommend a brucella test within six months for any frozen semen patient. Also, be sure to bring your dog’s registration paperwork (if associated with a club) to your appointment. Some clubs also require DNA registry, which we can acquire at the time of the first freezing appointment if he has not had his DNA registered. DNA registry is a requirement for all AKC canine frozen semen.

Frequently Asked Questions

  • At what age should an animal be evaluated if they are going to be used for breeding?
  • Each breed of dog or cat has its own group of important health concerns that are regularly screened for before breeding. Some of these tests are genetic tests and can be evaluated at a young age, while others require the animal to be 1-2 years old for evaluation. It is important to have your dog or cat examined for any of these concerns before breeding plans commence. Although most of our animals are fertile at between six and twelve months of age, we also recommend that female animals have a mature body frame, which is especially important when considering that she will carry a pregnancy.
  • What is involved in ovulation timing for planning a breeding?
  • For most dogs, we recommend coming in 5 days after signs of heat begin. A physical exam is performed during the initial exam, and a plan formed based on the type of insemination and availability of the stud dog. Vaginal cytology, vaginoscopy (looking at the vaginal wall visually), and progesterone levels are parameters we use to evaluate her cycle, and recommend a window of optimum fertility. Our progesterone machine is on-site, and we receive same day results.
  • What is the best time to breed my dog to increase conception and litter size?
  • Conception rates and litter size will be optimized with ovulation timing. Her cycle can vary greatly. Some dogs will have a fertile window as soon as 6 days after her heat cycle begins, while others will not be ready for a month! Both the male and female are involved in a successful conception, so it is important for us to evaluate both her cycle and his semen before insemination occurs. Selecting a stud dog with previous history of good conception rates and litter sizes is an excellent choice to increase reproductive efficiency of your program. Trans-cervical insemination will result in the highest pregnancy rates and litter sizes of the modalities we use commonly. Natural breeding in reproductively healthy animals also will have excellent conception rates.
  • How is vaginal artificial insemination performed?
  • The vaginal AI is a procedure in which a small catheter is passed into the vagina close to the cervical opening, where semen is deposited. This procedure simulates where semen would be placed in a natural breeding. It is an excellent choice for two dogs of excellent fertility that cannot be bred naturally due to temperament, size, or location of the stud dog. 
  • How is trans-cervical insemination performed?
  • Trans-cervical insemination is a procedure in which a rigid endoscope is placed into the vagina and the cervix is visualized using a camera. The cervix is catheterized, and the semen is placed into the uterus. The animal is awake during the procedure. Fresh, fresh chilled, or frozen semen can be successfully used by this method.
  • Do you perform surgical inseminations?
  • We work in conjunction with the surgery and anesthesia staff to accomplish surgical inseminations for our clients. Because it has been shown that trans-cervical methods yield comparable results to surgical implantation, it is unusual that we recommend this procedure. We are happy to accommodate clients requesting the service. This type of insemination is more expensive than other alternatives, and the dog is under general anesthesia for insemination.
  • When should pregnancy evaluation occur?
  • If ovulation timing was performed, we recommend pregnancy ultrasound 28 days after the LH surge. If dogs were bred naturally without any ovulation timing, we recommend seeing these dogs at 28 days after the last breeding. Heartbeats and fetal health can be evaluated at this time, and a rough idea of litter size can be estimated. Litter size is important when considering feeding recommendations in mid to late pregnancy.
  • Why should I get a pregnancy x-ray if I already know she’s pregnant?
  • We recommend radiographs during the last week of pregnancy. This is recommended for getting a more specific puppy count, as well as evaluating the birth canal width in relation to puppy size. If puppies are too large, a caesarian section may be indicated. If you have a clear idea of how many puppies she should have, you can make better decisions at home before deciding she needs veterinary help. If she delivers 6 puppies (and you saw 8 on radiograph), then stops pushing and seems “done”, you know that she may need assistance to complete her delivery.
  • What is your protocol for preparing a dog for elective c-sections?
  • Ideally, an accurate due date range can be established based on proper ovulation timing at the time of breeding. Close to her due date, we will monitor the drop in her progesterone concentrations to determine whether she is fully term. It is also possible to evaluate the fetuses with ultrasound to determine how “ready” they are.
  • Do you perform emergency c-sections?
  • Yes. We work in conjunction with the surgeons and anesthesia service to move emergency c-sections as quickly to surgery as possible. There are always staff members on-call and available to handle your emergent situations.
  • Does the service perform semen freezing?
  • Yes. Semen collection and subsequent freezing is a regular service we provide. We provide freezing for normal, healthy animals one day a month. This is ideal so that we can book only freezing appointments and focus all of our attention on the freezing process throughout the day. If your dog has a more emergent concern regarding his overall or reproductive health, an appointment can be arranged on a more immediate basis. We store semen on site, and can facilitate use of the semen here or shipment for use at other veterinary facilities.
  • What do I need to bring for my semen freezing appointment?
  • It is important to bring AKC or other club registry information for the dog and a copy of the DNA test, if the dog has had semen frozen before. All AKC registered dogs are required to have a DNA registry number. We recommend a brucella test be acquired within 6 months of the collection appointment. If your dog is brucella negative within the timeframe, we may be able to provide a teaser female to help us acquire the best collection possible.
  • Can male cats be evaluated for fertility?
  • Yes. Male cats can be collected while under general anesthesia. By using a rectal probe that stimulates the nervous system, the cat is stimulated to ejaculate. The sperm collected can then be evaluated for abnormalities. Some cats can be trained to collect voluntarily into an artificial vagina; however the majority of cats are evaluated using the rectal probe technique under anesthesia.
  • Do you perform any genetic or routine health testing for dogs?
  • Yes. OFA hips, elbows, and shoulder, evaluations can be performed with the help of the radiology staff. OFA dentition and thyroid testing are also available. Genetic testing varies between tests, but often requires a blood or cheek swab sample that we can acquire for you. Additional testing, such as cardiac, BAER (hearing) testing, and CERF (eye) evaluations can be performed at UC Davis as well, but are seen individually on the cardiology, neurology, and ophthalmology departments, respectively. We can often arrange “back-to-back” appointments between our departments to accommodate multiple tests during one visit.
  • What diets are optimal for breeding animals?
  • For female dogs, “all life stages” diets are appropriate for early and late pregnancy, as well as during lactation. For stud dogs and non-pregnant or lactating females, most adult formulations are adequate. Well-made foods with complete AAFCO certifications (both an analysis of the ingredients and a feeding trial) are excellent choices. Supplementation of minerals, vitamins, and other additions is not necessary if the dog is on a high quality food, and it is not generally recommended.
  • When should a female be evaluated if infertility is suspected?
  • Even with ovulation timing and good breeding management, pregnancy does not always result. The #1 reason for perceived “infertility” is improper timing for natural breeding or other insemination technique. After two attempts with good timing without diagnosed pregnancy, further evaluation is often indicated. There are many things that can result in poor conception rates, which include uterine problems, contagious disease, stress, issues with the stud dog, and others. Diagnostics such as physical examination, discussion of at-home care, uterine cultures, or uterine biopsy may help to further understand a cause for infertility.
  • What can be done if an accidental breeding occurs?
  • If an animal is bred accidentally and conceives, a few options exist for treatment. In the case of animals that do not have future breeding plans, ovariohysterectomy (spay) is an excellent solution. If the animal is involved in a breeding program, the pregnancy can be terminated medically. If performed properly, this should not impair her future fertility, and she can be bred successfully at a later date. Some owners will choose to have them carry the pregnancy, and pregnancy monitoring would commence at that time.
  • Will you come in on the weekend? After hours?
  • Yes. We understand that breeding is time sensitive, and we will often recommend weekend procedures if it is best for optimizing conception rates. There is no additional cost for clients we are currently managing for breeding. If you are not a regular client, we may be available to come in for your dog, but an additional emergency fee will be included for the appointment.
  • What resources are available for client education about breeding?
  • Handbooks helpful in understanding the basic concepts of husbandry, breeding, and management are available. Some are more helpful than others, and they vary from being beginner to expert in content. Having a reputable author is important to select for, as there are many books with great claims, but poor contents and incorrect data. We often provide handouts in the clinic for our clients regarding their individual needs, and are available for questions at any time. If you are new to your breed, it is an excellent idea to build a relationship with an experienced mentor who can help guide you during the breeding process and share their experiences.


Ghislaine DujovneGhislaine Dujovne, DVM, MS, DACT
Chief of Service



Janice CainJanice Cain, DVM, DACVIM
Staff Veterinarian



Autumn DavidsonAutumn P. Davidson, DVM, MS, DACVIM
Staff Veterinarian




villanuevaEduardo Santos Villanueva, DVM
Resident II