New Bolton Center Kennett Square, PA
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Ryan Hospital Philadelphia, PA
puppy and mom

Small Animal Reproduction

Our reproductive specialists understand the emotional commitment, financial investment, and pride that go into breeding and showing purebred dogs and cats. Be assured that we will assist you with all of your reproductive needs to produce and maintain the healthiest breeding stock possible.

Our board-certified reproductive specialists offer state-of-the-art reproductive services for both male and female dogs and cats.

We want to provide you with the optimal tools for an excellent breeding program and outstanding offspring.

Our board-certified reproductive specialists offer state-of-the-art reproductive services such as:

  • Breeding soundness examination
  • Semen collection, evaluation, freezing, shipping, and storage
  • Side-by-side artificial insemination
  • Pregnancy evaluation

Our veterinarians are available for consultations on infertility in male and female cats and dogs, as well as on developing and maintaining sound breeding programs.Small Animal Reproduction, Penn Vet

Pedigrees may be reviewed as needed and nutritional guidelines during pregnancy discussed.

The Reproduction Clinic is a place for clients to discuss and explore all issues related to propagating successful, competent and sound breeding practices. Artificial insemination and assessment of fertility problems in both sexes of canine and feline species as well as advise regarding castration and spaying are offered.

Dog and puppy, Penn Vet


For an appointment, please contact the Ryan Veterinary Hospital appointment desk: 215-746-8387.

This clinic is available to the public on a non-referral basis, and breeders and new puppy or kitten "parents" are encouraged to contact us.

It also serves as a referral clinic for more complex disorders and problems related to pediatrics, genetics, and reproduction. Clients may also be referred here by their primary care veterinarian.

When to call the vet

Seek immediate veterinary care if you observe:

  • Collapse
  • Tremors
  • Fever
  • Puppy stuck in the birth canal
  • Green vaginal discharge (lochia) before the birth of the first puppy
  • Severe bloody vaginal discharge for more than 12 hours after labor
  • Sudden drop in temperature (2-3°F) at the expected due date, which is normal, but then an increase in temperature beyond 101°F before any puppies are born
  • Strong abdominal contractions with no puppy produced within one hour
  • Lack of another puppy after the birth of one puppy and two hours of additional contractions
  • Gestation lasting more than 65 days without the onset of labor

To ensure ideal breeding stock, a stud needs to be healthy, receive good nutrition, and be parasite-free. Experts in Penn Vet’s Small Animal Reproduction Service can perform a full physical examination, including a brucellosis test, as well as provide nutrition recommendations and parasite control prior to collections. Penn Vet also offers semen collection, evaluation services, and freezing services, including shipping and receiving for transcervical artificial insemination, vaginal artificial insemination, and surgical artificial insemination.

  • Sperm evaluation
    • Concentration: Semen evaluation has three fractions to make up the total collection. The second fraction contains the sperm cells, which determines the concentration.
    • Total sperm/ejaculate: This allows for determination of the number of potential bitches that can be bred by a single collection, if well concentrated.
    • Motility: Evaluation of whether or not the sperm cells are exhibiting any movement and if they are moving in a forward or circular progression.
    • Morphology: Evaluation of the appearance of sperm cells to determine any abnormalities. More than 80 percent of sperm cells should be morphologically normal.
  • Stud evaluation
    • Testicular evaluation: Size and width may be measured with ultrasound or calipers.
    • Testicular orientation and palpation: To check for problems such as testicular torsion (very painful enlargement) and potential for testicular tumors.
    • Penis evaluation: To check for disorders such as persistent frenulum, urethral prolapse, and transmissible venereal tumors.
    • Semen production: To determine if the male is producing semen but not delivering upon collection due to incomplete ejaculation or retrograde ejaculation into the bladder.
    • Disease evaluation: To check for inherited diseases that may interfere with normal semen production.
  • Freezing or chilling your dog’s semen
    • Many owners and breeders will pursue these options when their older male has had a decrease in litter production compared to previous breeding.

      Some owners may wish to have potential breeders collected early in their career, especially when the dogs are intended for future pet ownership or are known to have desirable genetic traits. Semen intended for more immediate use and breeding may be chilled and shipped nearly anywhere. 

      If you are interested in having your AKC pups registered, you must use an AKC-approved semen freezing facility, such as Penn Vet.

      A minimum of 250 million normal, progressively motile spermatozoa are recommended for a fertile vaginal breeding. A minimum of 100 million normal, progressively motile spermatozoa are required for intrauterine breeding.

To maintain a pregnancy, a bitch needs to be healthy, receive good nutrition, and be parasite-free. Experts in Penn Vet’s Small Animal Reproduction Service can test for brucellosis, perform your breeding timing, and perform an examination to ensure optimal health.

Penn Vet offers a wide range of breeding management services, including hormone testing, cytological evaluations, vaginoscopy, transcervical artificial insemination, vaginal artificial insemination, and surgical artificial insemination.

  • Ways to determine optimal timing for breeding
    • Behavior assessment: In proestrus, the bitch will be attractive to males, but will not allow mating. During estrus, the female will flag, or lift her tail to the side, and allow mating. Not all bitches follow these rules, making this the most inaccurate method of timing.
    • Vaginal cytology: This method allows for an indirect look at estrogen levels. As estrogen rises, cells change their appearance, revealing the stage of the bitch’s cycle. This method is quite accurate, but does not allow for prediction of ovulation or insemination date.
    • Vaginoscopy: This is performed with a scope attached to a light, allowing for inspection of the vaginal wall.
    • Progesterone and LH measurements: Progesterone can be measured every other day in conjunction with cytology during proestrus. As the dog enters estrus, the vaginal cytology changes and the progesterone increases. Evaluation then increases to once daily in order to capture the LH peak. Breeding should occur two to three times every two days until the estrus stage has passed. This is the most effective way to increase chances of pregnancy and litter sizes. Exact timing is most important when breeding with chilled or frozen semen and when planning a C-section.
    • LH surges: LH surges can last only 12 hours, making them difficult to catch. But they are the best predictors of ovulation and the optimal time for breeding.

Phases of the Heat Cycle

Here are the four phases of the heat cycle:

  • Phase I: Proestrus
    • (beginning of the heat cycle) – average of nine days
    • During this phase, you will notice bloody vaginal discharge. In addition, the female will not stand to be mated.
  • Phase II: Estrus
    • (standing heat) – average of nine days
    • You will notice less bloody vaginal discharge during this phase. In addition, the female will stand to be bred.
  • Phase III: Diestrus
    • average of 60 days
    • Hormone levels will change during this time, as progesterone levels increase in order to maintain pregnancy. This change will occur whether mating has occurred or not.
  • Phase IV: Anestrus
    • average of four to seven months, depending on breed
    • This phase is characterized by a lack of hormonal activity. It is best to perform a full physical examination shortly before the bitch is expected to go into heat. Nutrition recommendations and parasite control can be discussed at this time.

Careful management of pregnancy and birth is important to ensure the health of both the mother and puppies. Experts in Penn Vet’s Small Animal Reproduction Service offer pregnancy and Puppies whelping, Penn Vetwhelping services, including:

  • Pregnancy nutrition and preventative care consultation
  • Pregnancy and litter size confirmation
  • Pregnancy ultrasound and radiographs
  • Labor consultation
  • C-sections

Pregnancy confirmation can be achieved through:

  • Relaxin RIM test: This hormone test can detect pregnancy at three to four weeks, using a blood sample.
  • Abdominal ultrasound: The most accurate diagnosis of pregnancy, it can determine viability after four weeks.
  • Palpation: On average-sized relaxed dogs, puppies can often be palpated between 21 and 28 days.
  • Radiographs: This is the most accurate method for determining a “puppy count” or estimated litter size.

Maternal care during pregnancy:

  • Vaccines: For maximum protection, the bitch should be vaccinated prior to breeding. The dam’s immunity will then be passed on through the colostrum, or first milk, to the pups just after birth.
  • Nutrition: A complete, well-balanced, high quality commercial diet (AAFCO approved) is recommended. Supplements are not necessary; in fact, additional calcium can be dangerous.
  • Deworming: A mother can pass parasites to her puppies through her milk and placenta. In order to prevent this transmission, deworming using safe medications is recommended.

About Pregnancy

p> In dogs, pregnancy typically lasts about two months. Within seven to eight weeks, you may notice weight gain, abdominal and mammary enlargement, and milk production in the mother.


About C-Sections

An emergency C-section may be necessary in some cases. Certain breeds of dogs may predispose to complications during birth. Penn Vet can work with you to schedule a planned C-section.

Stages of Canine Labor

  • Temperature drop
    • About 24 hours before the onset of active labor, the resting rectal temperature of the bitch may fall by at least one degree from her normal temperature, or drop to around 99°F.
  • Stage I: Labor/Pre-contractions
    • About six to 12 hours before the onset of active labor, the bitch may become restless, agitated, or clingy and start to pant or nest. Make sure a clean, dry, appropriate whelping box is made available.
  • Stage II: Active contractions
    • The first puppy should be produced within one hour after the start of active abdominal and vaginal contractions. The following puppies should be born within 20-60 minutes of additional contractions. An entire litter is typically born with in three to six hours. It is not uncommon for the pups to be born breech (feet first).
  • Stage III: Labor/Expulsion of the placenta
    • The placenta is typically expelled following the birth of a puppy. Sometimes a few pups will be born in a row and then the placentas will also be expelled in a row. The number of placentas should match the number of puppies born.
  • Removal of the membranes
    • The mother will typically tear the fetal membranes from the face of the pup and bite the umbilical cord. If necessary, you can gently tear the membrane and tie off the umbilical cord. Immediately following, the puppies should start breathing and rooting toward the dam’s nipples to suckle.