Canine Reproduction

Estrus (Heat), Pregnancy, Pseudopregnancy, Spaying and Neutering in Dogs

Learn the average age and length of the first heat cycle, pregnancy length, and about spaying and neutering in dogs. Also learn about abnormal conditions such as ectopic ovaries and pseudopregnancy (false pregnancy).

  • 01 of 11

    Pregnancy, Estrus (heat) Periods and Spaying of Dogs

    Pregnant - Day 56 by Renee V on Flickr
    Pregnant - Day 56.

    Renee V / Flickr

    Common canine reproduction questions, including: For how long is a dog pregnant? Do female dogs experience menopause? How long does a dog stay in heat (estrus)? What about spaying (ovariohysterectomy) surgery? Learn the answers to these questions and more in this FAQ.

  • 02 of 11

    Spay Operation—Ovariohysterectomy

    Veterinary anesthetic machine and tubes © Janet Tobiassen Crosby DVM
    Veterinary anesthetic machine and tubes.

    Janet Tobiassen Crosby DVM

    Learn the terminology and what happens before, during and after the spay operation in female dogs and cats.

  • 03 of 11

    Neuter Operation—Photo Gallery

    Dog neuter surgery by Janet Tobiassen Crosby DVM
    Dog neuter surgery.

    Janet Tobiassen Crosby DVM

    Enter the operating room and see a canine castration, more commonly known as dog neuter surgery. This procedure requires general anesthesia maintained with inhalation (gas) anesthetic.

    Related: Neutering Q & A

  • 04 of 11

    How Long Does the Heat Cycle Last in Dogs?

    Close up by inajeep on Flickr
    Close Up.

    inajeep / Flickr

    Most non-spayed female dogs will typically go into "heat" or estrus twice a year. The age at which they start their cycles and the duration of the cycle varies greatly between the breeds of dogs and individual dogs. Learn more facts about canine estrus in this FAQ.

    Continue to 5 of 11 below.
  • 05 of 11

    Can You Spay a Dog in Heat?

    Mo the cat getting 'fixed' © Bill in Ash Vegas on Flickr
    Mo the cat getting 'fixed'.

    Bill in Ash Vegas / Flickr

    The short answer is yes, a dog that is in heat (called estrus) may be spayed. However, there are increased risks and costs due to the potential for additional blood loss. The age, weight and general health of the patient are also factors to consider.

  • 06 of 11

    My Pet Was Spayed, but Now Looks Like She's in Heat

    Sky Dog by ms.Tea on Flickr
    Sky Dog.

    ms.Tea / Flickr

    Question from a viewer: "Our female dog was spayed when she was four to five months old. She is now 1-1/2 years old and bleeding; our male dog keeps trying to mate with her. The vet told my husband that sometimes this happens and that the way the dog's uterus is sometimes they miss an ovary and have to go back in. I cannot see that this is possible if they removed the uterus. Does anyone know if this is possible?"

    Related: What is an Ectopic Ovary?

  • 07 of 11

    Pseudopregnancy or False Pregnancy

    Sweet Face / The_Vikkodamus on Flickr
    Sweet Face.

    The_Vikkodamus / Flickr

    Pseudopregnancy is the medical term for a condition known as false pregnancy. This condition occurs several weeks (the average is eight to nine weeks, but it may be as long as 12 weeks) after the canine's estrus cycle. Pseudopregnancy is rare in cats.

  • 08 of 11

    Cryptorchidism in Dogs

    Dachshund / AndreaDeak on Flickr
    Dachshund / AndreaDeak on Flickr.

     AndreaDeak / Flickr

    Cryptorchidism is when one or both testicles fail to descend into the scrotum. This condition is a fairly common problem; seen in dogs, cats, and other animals. This is a well-documented genetic trait—animals with this condition should not be bred. Find out why in this FAQ.

    Continue to 9 of 11 below.
  • 09 of 11

    Will Littermates Mate?

    Maltese-Shihtzu puppy by wsilver on Flickr
    Maltese-Shihtzu puppy.

    wsilver / Flickr

    This question has come up for both dogs and cats. Viewers want to know if once littermates reach puberty, will they...mate? Or will they "know" they are brother and sister and refrain?

  • 10 of 11

    Is It OK to Vaccinate My Pet If She Is Pregnant or Nursing?

    Litter of Puppies / Katie@! on Flickr
    Litter of Puppies.

    Katie@! / Flickr

    If you know or suspect that your pet is pregnant, caution is advised when considering vaccinations. In some cases, the health of the mother or legal requirements (i.e., travel) may require vaccinations. This FAQ discusses various health risks associated with pregnant or nursing animals and vaccinations.

  • 11 of 11

    Dog Normals

    Veterinary technician monitoring a patient's vital signs © Janet Tobiassen Crosby DVM
    Veterinary technician monitoring a patient's vital signs.

    Janet Tobiassen Crosby DVM

    Knowing the normals—heart rate, respiration, temperature and length of pregnancy—will help you be a keen observer and advocate for your pet's health.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.