Progesterone Testing & Vaginal Cytology

Before deciding to breed your dam, make sure to have your female and male both tested for Canine Brucellosis.

Progesterone testing and vaginal cytology are two methods that can be used to evaluate a dog's reproductive health and to identify any potential hormonal imbalances or abnormalities.

Progesterone testing involves taking a blood sample from a dog and measuring the levels of the hormone progesterone in the bloodstream. Progesterone is produced by the ovaries and plays a key role in the menstrual cycle and pregnancy. High levels of progesterone can indicate that a dog is pregnant or has a hormonal imbalance, while low levels may indicate that the dog is not ovulating or is experiencing other hormonal problems.

Vaginal cytology involves taking a sample of cells from the inside of a dog's vagina and examining them under a microscope. This can help to identify any abnormalities or infections that may be present in the reproductive tract. Vaginal cytology can also be used to determine the stage of the menstrual cycle and to identify any hormonal imbalances.

Both progesterone testing and vaginal cytology are important tools for evaluating a dog's reproductive health and can help to diagnose and treat any potential problems. It is important to work with a veterinarian when considering these tests for your dog.

Vaginal Cytology

A vaginal cytology is an evaluation commonly done. The cells seen at the ideal time for breeding are a high percentage of cornified epithelial cells, with few red blood cells (RBC’s), white blood cells (WBC’s) or debris. The vaginal smear may also indicate the presence of other problems such as vaginitis. The test is simple, safe, inexpensive, well tolerated by the bitch approaching estrus, and very helpful in timing breeds.

Examination of a single smear can provide useful information, but can also be misleading. For example, it is often difficult to differentiate proesterus and disestrus from an isolated smear. It is most useful to evaluate multiple smears taken from the same bitch. These slides can be labeled with the date collected and stored for evaluation sequentially as she moves through her estrus cycle to monitor trends in cellular cornification.

Progesterone Testing

A quantitative progesterone blood test is the single most accurate method for timing breedings. The test is reported as a numeric result, usually ng/dl. Combined with observing the behavor of the dog and bitch, vaginal cytology, ovulation can be pinpointed with great accuracy in most bitches.

An exact progesterone level is also needed when the dog or bitch will be traveling a long distance for breeding, when fresh chilled or fresh semen is to be used, or when breeding dogs or bitches that have a history of being difficult to breed. In addition, an exact progesterone level for timing ovulation is necessary when a C-section is anticipated or when the bitch is near term and fetal survivablility needs to be assessed.

There are some veterinary clinics that have a high enough volume of progesterone samples that they have purchased equipment (Immulite, Tosoh, or Mini-Vidas) to run quantitative progesterone samples in their veterinary clinics. *We use MicroVet Cube which is comparable to Immulite.

Progesterone Interpretation

The canine’s reproductive system is unlike any other species. This is probably the most confusing part of canine reproduction. Many breeders and many veterinarians do not understand the cycle well until they see it graphed. Once you understand that progesterone rises slowly and stays high throughout the cycle.

At the start of the strous cycle, proestrus, the estrogen levels are rising. The hormone of interest, progesterone, of the bitch is at avery low level, less than 2ng/ml. This is often reffered to as “baseline”. During proestrus in a normal bitch that has started estrus spontaneously (without drug or hormone intervention), the first progesterone level should be run on day 5 to day 6 of her cycle.

As the bitch enters estrus, she approaches her fertile period and her progesterone level will rise above 2ng/ml. She will become increasingly attractive to the male and receptive to his advances. This slight rise is often called the initial rise. Its only significance is that you will want to monitor her progesterone levels more closely now as she is about to ovulate. Bitches are only fertile for a few short days during estrus, not the entire time they are in estrus.

As the progesterone rises above 2 ng/ml, continue to draw serial serum samples for testing, usually every 1 to 3 days.

Ovulation is though to occur when the progesterone level reaches 5 ng/ml. This may be the single most important concert regarding breeding in this book. The bitch’s ovary responds to the LH from the pituitary, which allows the release of one egg from each of many multiple mature follicles.

But stop: it is too early to breed if you are using fresh chilled or frozen semen. When the bitch ovulates, the eggs are not yet mature and ready to fertilize. Unlike in other species, the eggs mature over the next 48 hours before they are ready to fertilize. The timing of the breeding must occur when the eggs are mature and ready to fertilize and viable semen is in the oviduct, estimating how long the semen is anticipated to survive in the reproductive tract.

Breeding with fresh semen, by either natural breeding or vaginal AI with fresh semen, can be done on the day of ovulation, when the progesterone level reaches 5 ng/ml. Although the eggs are not mature yet, most fresh semen is viable enough to survive in the bitch’s reproductive tract until the eggs are ready.

Breeding with fresh chilled semen should be delayed until approximately 48 hours after ovulation. Fresh chilled semen usually will not survive as long in the reproductive tract as fresh semen. If the fresh semen is deposited vaginally or directly into the uterus 2 days post-ovulation, the eggs should be fertile when the semen appears in the oviduct.

Breeding with frozen semen should be delayed even longer, 60 to 80 hours after ovulation (Ovulation occurs when the progesterone is at a 5 ng/ml). It is thought most frozen semen will only live 12 to 24 hours (or less) in the reproductive tract. For this reason, the semen should arrive in the oviduct when the eggs are mature and ready to fertilize. If necessary to choose, it is better to breed slightly too late than slightly too early. most breedings with frozen semen are done by depositing the semen directly into the uterus, usually by surgical insemination but in some cases by transcervical insemination.

Once the progesterone level is 5 ng/ml the vet is still not done testing. Although it is believed that ovulation occurs around the time the bitch’s progesterone reaches 5 ng/ml, we still need to keep our eye on one more number; that number is a progesterone level of a 20 ng/ml. (nanograms per milliliter). To assure that ovulation is complete and the progesterone level is high enough to maintain a pregnancy, delay either the final or the surgical insemination until the progesterone level has reached or exceeded 20 ng/ml.

After ovulation and breeding are completed, the progesterone level will continue to rise. The level typically rises to 40 to 50 ng/ml (the normal range can be 10 to 90) whether the bitch is bred, pregnant, or not. An elevated progesterone level only indicates that the corpus lutea in the ovaries can support a pregnancy, not that the bitch is pregnant. Bitches maintain this level unless they have ovarian or uterine pathology.

Greer, Marthina. “Chapter 3: Preparing to Breed.” Canine Reproduction and Nenatology. Jackson: Teton NewMedia, 2015. 46+. Print.

Canine Brucellosis

​​​Disease Basics

Brucellosis is a contagious disease caused by the Brucella bacteria. This bacterium primarily affects the reproductive organs of male and female dogs. Brucellosis can cause infertility and late abortions in female dogs. In male dogs, it can cause testicular or scrotal inflammation and infertility. This disease can also cause puppies to be stillborn or very weak at birth.

​Brucellosis can infect dogs of any breed and any age, though it is most common in mature dogs. It is transmitted by contact with infected fluids, especially during breeding or birth, and is a zoonotic disease, which means it can be transmitted to humans. 

Prevention

Canine brucellosis is mainly transmitted by nose and mouth contact with vaginal discharge from an infected female.  It can also be transmitted through semen or urine and can be shed by intact or neutered males for several years in cases of chronic infection. Therefore, the best way to prevent the transmission of brucellosis is to minimize exposure.  Keep healthy dogs away from known infected dogs. Before breeding, both the male and female dog should be examined by a veterinarian and tested for the disease.  Dogs should not be bred if they test positive for brucellosis.  Reducing the risk of exposing dogs also reduces human risk. 

​Clinical Signs of Illness

If a dog has brucellosis, he or she will probably exhibit some of the following signs:

• ​Lethargy

• Swollen lymph nodes

• Difficulty walking

• Back pain

• Weak, sickly newborn puppies

• Vaginal discharge

• Swollen testicles

• Inflammation of the skin around the scrotum

Diagnosis/Treatment

Brucellosis can be a difficult disease to diagnose.  A veterinarian may recommend several tests to confirm the diagnosis.

If a dog has been diagnosed with brucellosis, the veterinarian will most likely recommend spaying or neutering to prevent the transmission of the disease to other dogs. Additionally, a combination of antibiotics will likely be recommended to treat the dog. Follow up testing for brucellosis is recommended to assess if treatment is successful.

​Human Health

Brucella bacteria can infect humans, but the severity of the infection can vary and is difficult to diagnose in people. Those who work in close contact with dogs, such as kennel operators, dog breeders or those in research or diagnostic laboratories, are considered to be most at risk for B. canis infection. However, people with immune compromise due to illness or immunosuppressive therapy and children or pregnant women are vulnerable to brucellosis.  

Source: https://datcp.wi.gov/Pages/Programs_Services/DogBreedersSellersLaw.aspx