Can a dog get pregnant by more than one dog?

Several different puppies can be born in a litter, is it possible that they are from different fathers? To answer this question, this post will talk about dog reproduction and pregestational, gestational and post gestational care.

Can a dog get pregnant by more than one dog?

Yes, it is possible for a female dog to become pregnant by more than one dog. This happens because female dogs ovulate several immature oocytes that can stay up to 3 days in the female reproductive tract for their complete maturation.

If during this period the female dog reproduces with more than one male, the different spermatozoa have the possibility of fertilizing different eggs and thus leading to the pregnancy of dogs from more than one father.

On the reproductive cycle of female dogs

Female dogs have a monoestrous, non-seasonal, reproductive cycle. The reproductive cycle in these animals is called the estrous cycle and can be divided into 4 phases:

  • Proestrus;
  • Estrus;
  • Diestrus;
  • Anestrus.


In proestrus, the female canine body is preparing for ovulation and pregnancy. In this phase, hormones make the females have vulvar swelling, bleeding and become more attractive to males. However, at this stage the female still does not accept the male’s copulation.

It is the phase of the “dating” of the dogs, it involves games of attraction between the dogs. Female dogs can be more agitated during this period and even run away. It is important to beware of unwanted leaks.


Estrus, also known as heat, is the period in which the female accepts the male dog’s copulation. It is at this stage that ovulation of the female dog takes place. So only copulations in this period will make the female dogs get pregnant. Estrus can be shorter in some animals as well as longer in others, ranging from 7 to 21 days on average.

In female dogs, the vulva remains swollen, but the bleeding may stop. Care must be taken, as many owners think that the heat is over because the dog has stopped bleeding. But many times, she is just going through her most fertile period.


The diestrus is the phase in which the uterus prepares to receive the embryos, it lasts from 58 to 68 days. Female dogs reduce vulvar edema, and may present translucent secretion in the vulvar region. It is at this stage that many bacteria can develop in the utero of female dogs resulting in pyometra. And when female dogs reproduce in estrus, diestrus becomes the fetal developmental stage of pregnancy.


Anestrus is the longest phase, lasting up to 4 months in some animals. In this phase, hormonal quiescence occurs in female dogs. Normally at this stage, female dogs do not accept the mount, much less the male’s copulation, and thus can be quite aggressive. The vulva returns to its normal size which makes copulation even more difficult.

Pre-pregnancy care for females dogs

Breeding dogs should always be accompanied by a veterinarian. Only healthy dogs should be bred, so blood tests and tests for sexually transmitted diseases in dogs should be done.

Healthy female dogs must be vaccinated before mating and a deworming protocol must be carried out to avoid contamination of puppies intrauterine or after birth.

Some female dogs can become very aggressive with males when the correct time for breeding dogs is not respected. Many times, animals can end up injured. 

Also, it is not advised to leave the male and female together during the entire time of estrus. Because dogs can spend hours trying to copulate, thus stressing each other. In addition to having the possibility of getting hurt from trying so hard to copulate.

It is important that the female only breeds with one dog, so that the pedigree of the animal can be traced. If the female reproduces with more than one male, DNA tests may be necessary to prove which puppies are whose offspring, thus making the process of dog reproduction more expensive for the tutors.

Some animals should receive vitamin supplements before and in the first days of pregnancy to avoid malformation problems in dogs. Female dogs must be at the ideal weight for the species, it is not desirable for obese or very thin females to breed. The diet of the pregnant dog can also change, so that the animal does not lose so much weight at the end of pregnancy.

Pregnancy care for females dogs

Gestation in female dogs can last from 58 to 63 days and can be extended up to 72 days or reduced to 57 days.  During pregnancy, it is important for the female dog to undergo a periodic gestational follow-up, where the veterinarian will observe any changes in the animal’s health through examinations. 

It is advised to perform an ultrasound on day 30 of gestation for gestational diagnosis and from day 55 of gestation to observe if the puppies are well. X-rays can also be performed after 50 days to count the puppies, which can help at the time of birth to define whether the birth is over or not.

During pregnancy, female dogs must receive specific diets, usually more caloric to meet all the needs of the animal’s body, which must, in addition to maintaining its own physiology, feed the puppies and produce milk.

During the gestational period, female dogs should be in comfortable environments, with as little stress as possible. Low impact physical activities can also be done, but with great care so that the animal does not get hurt, thus putting the lives of the puppies at risk.

And on the day of parturition, what to do?

On the parturition day, separate clean towels to dry the newborn puppies, and sterilized scissors, in case it is necessary to cut the puppies umbilical cord. Leave the vet on alert in case of any problem at the time of parturition, so the vet can do emergency care to the patient and her puppies as needed.

The parturition can take up to 12 hours to complete and the interval between the births of the puppies cannot be longer than 2 hours. If the interval between puppies is too long, see a veterinarian.

Parturition in female dogs can be normal or eutocic, when the female dog does not present difficulties in giving birth to the puppies alive. Difficulties at the time of parturition in female dogs is called dystocia, when proper dystocia treatment by a vet is not performed, many puppies and parturient can die.

Postpartum care in female dogs

After parturition, some female dogs may need a food supplement due to the high energy demand of milk production. Therefore, a veterinary nutritionist should be consulted.

Dogs should stay in warm, calm and quiet places and should be avoid picking up puppies from the female dog. Puppies do not control temperature so they should stay in warm places. For the first few days, puppies should only feed on the mother’s milk. And from the fourth week onwards, specific diets for puppies can be introduced.


Female dogs can have puppies from different dogs due to their ovulation of multiple eggs that can be fertilized by sperm from different males. Pregnant dogs need a lot of care to avoid complications during pregnancy. Care at the time of delivery and postpartum can also be very important to maintain the health of the parturient and puppies.

Frequently Asked Questions (FAQs): Can a dog get pregnant by more than one dog?

Is it possible to manipulate a female dog’s estrus with drugs, as in cows?

Yes, it is possible, but it is not so used because many female dogs also do not respond to hormonal protocols, so few animals go into heat. Therefore, it is recommended to let the animal come into heat naturally and the tutor will be accompanied until the exact moment of reproduction.

How long does pregnancy last in female dogs?

On average, the duration of pregnancy in female dogs is 63 days, ranging from 58 to 68 days from the day of mating. Veterinarians can dose hormones that will give a more accurate date for parturition. In addition, there are imaging tests that can indicate approximate parturition dates in female dogs.

Can female dogs have more than one heat per year?

Yes, some dog’s breeds can come into heat every 4 months. However, care should be taken as constant repetitions of heat can be a sign of endocrine diseases, so a veterinarian should be consulted to avoid health problems in dogs.


de Souza Teixeira, E. (2001). Princípios básicos para a criação de cães. NBL Editora.

Pinheiro, B. (2019). Gatas e cachorras podem ter filhotes de pais diferentes na mesma gestação? UFSM.

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