Your cart is currently empty.
How to Know If Dog Mating Is Successful: Clear Signs to Look For - PawSafe

How to Know If Dog Mating Is Successful: Clear Signs to Look For

Photo of Tamsin De La Harpe

Written by Tamsin De La Harpe

how to know if dog mating is successful

Mating is a natural process for dogs, but how when dog mating  is successful can be challenging. It can be difficult to know if the mating has resulted in a pregnancy and even harder to tell if the pregnancy is viable. 

Understanding the signs of successful mating can help dog owners and breeders identify pregnancy and ensure the well-being of the mother and puppies. You’ll also be able to make preparations like extra padded beds for the mother dog’s rest and nutritional supplements.

 It is important to monitor the female’s behavior closely after mating to ensure she is healthy and comfortable. We have drawn from sources like Aaron Wilmoor’s Dog Breeding Business guide  and the BSAVA Manual of Canine Reproduction for a deeper look into canine mating. 

Proper timing always precedes a successful mating. When your female dog is in her heat cycle, your male dog will exhibit signs that he wants to mate. Females are typically fertile for a short period, so it’s essential to ensure that the mating occurs during this window. However, a female dog typically will not allow mating unless she is in the fertile part of her cycle (as opposed to proestrus or other parts of her cycle).

Most matings are successful unless either the male or the female dog have a fertility problem, such as if they have a Brucellosis infection or other condition that could affect their ability to reproduce. Occasionally, young dogs may not have a successful mating during their first heat. But in general, if you see two dogs mating, chances are that it is successful. Unsuccessful matings are comparatively rare.

The female dog’s heat cycle lasts for about 21 days, and she is typically fertile (in estrus) for 3-5 days in. It’s best to have the dogs mate every other day during this time to ensure the best chance of success. 

Our article on Can female dogs get pregnant when not in heat? goes into detail as to why pregnancy cannot happen without heat.

Overall, determining if a dog mating is successful involves considering the timing of the mating, the behavior of the dogs, and physical indicators such as pregnancy and the presence of a tie. By paying attention to these factors, breeders can increase their chances of a successful breeding.

You may also like:

Disclaimer About Dog Mating & Breeding:

This article is intended for informational purposes only and should not be used as a guide for breeding dogs without professional guidance. We strongly discourage unethical breeding practices and backyard breeding, as these can contribute to the overpopulation of dogs and put a strain on shelters and rescue organizations.

Responsible breeding involves meticulous planning, thorough health screenings for both parents, and a commitment to the well-being of the puppies produced. If you are not prepared to meet these responsibilities, spaying or neutering your pet is the most ethical choice.

Understanding Dog Mating

Dog mating is a natural process essential for the continuation of the species. However, it can be difficult to know if a mating has been successful. You can check out our article on what to expect from your female dog after mating if you suspect the process was successful. 

When a female dog is in heat, she will release pheromones that attract male dogs. The male dog will then mount the female and attempt to mate. During mating, the male dog will penetrate the female dog’s vagina and ejaculate semen, which contains sperm. The sperm will then travel up the female dog’s reproductive tract to fertilize the eggs.

The most obvious sign of successful dog mating is the presence of a “tie” between the male and female dogs. A tie occurs when the male dog’s penis swells inside the female dog’s vagina, which can last for several minutes. 

Another obvious sign of successful dog mating is pregnancy. A female dog that has been successfully mated will become pregnant and show physical signs of pregnancy within a few weeks. These signs may include weight gain, enlarged nipples, and a larger abdomen.

It is important to note that not all dog matings result in pregnancy. The success of mating depends on several factors, including the timing of the female dog’s estrus cycle and the fertility of the male and female dogs. Understanding the estrus cycle in female dogs can help dog owners determine the best time for mating and increase the chances of a successful pregnancy.


Signs of Successful Mating

1. Tie Phenomenon

One of the most obvious signs of successful dog mating is the “tie phenomenon.” This is when the male dog’s penis swells inside the female dog’s vagina, causing them to remain physically connected for several minutes. This is a natural occurrence and is a sign that the male dog has successfully ejaculated and has transferred his sperm to the female dog’s reproductive tract.

2. Changes in Behavior After Mating 

After successful mating, dogs may exhibit different behaviors. Some dogs may become more affectionate towards their mate, while others may become aggressive or territorial. It is important to monitor their behavior to ensure they are safe and do not harm each other.

Behavioral Changes in Female Dog

A successful mating can also cause behavioral changes in the female dog. She may become more restless, anxious, or clingy. 

She may also exhibit nesting behavior, such as digging or rearranging bedding, in preparation for the birth of her puppies (mostly happens towards the end of the pregnancy). It is important to provide her with a comfortable and safe environment during this time.

Behavioral Changes in Male Dog

Male dogs may also exhibit behavioral changes after successful mating. They may become more protective of their mate and may mark their territory more frequently. They may also become more aggressive towards other male dogs in the area.

It is important to keep them separated from other dogs during this time to prevent any potential fights.

Vaginal Discharge

A female dog’s vaginal discharge undergoes various changes throughout her heat (estrous) cycle, and these changes can also be evident after successful mating. Here’s a breakdown:

During the Heat Cycle:

  1. Proestrus: The first phase of the heat cycle is known as proestrus, and it usually lasts between 7 to 10 days. During this stage, the female dog may have bloody vaginal discharge. She may attract male dogs but is typically not receptive to mating at this point.
  2. Estrus: This is the phase when the female is fertile and receptive to mating, which generally lasts around 5 to 9 days. The vaginal discharge changes in both color and consistency: it becomes lighter, often turning from a bloody red to a straw-yellow or clear color. This is often a sign that the female is ovulating and is the optimal time for mating.
  3. Diestrus: After the estrus phase, the dog enters diestrus. The vaginal discharge may become reddish again or cease altogether. The female is no longer receptive to males during this stage.
  4. Anestrus: This is the period of sexual inactivity between heat cycles, and no noticeable vaginal discharge is typically observed during this phase.

After Mating:

  1. Immediate Aftermath: After successful mating, it’s common to notice a small amount of clear to milky discharge. This is usually residual semen and some cellular material and is generally not a cause for concern.
  2. Pregnancy: If the mating results in pregnancy, you may observe no significant changes in vaginal discharge initially. As the pregnancy progresses, however, some dogs may have a clear to milky, odorless discharge. If you notice a bloody or foul-smelling discharge during pregnancy, consult a veterinarian immediately, as this could be a sign of complications.
  3. Non-Pregnant: If the dog does not become pregnant, she will move into the diestrus and then anestrus stages of her cycle, during which vaginal discharge will decrease and then cease, respectively.

Monitoring the changes in vaginal discharge can provide valuable information about a female dog’s reproductive status. 

Physical Indicators of Pregnancy

When it comes to determining if a dog mating was successful, physical indicators of pregnancy can be a helpful tool. Our article on signs a dog is pregnant covers this topic more extensively. Here are some of the most common physical signs to look for:

Increased Appetite

One of the earliest physical indicators of pregnancy in dogs is increased appetite. This is because the growing embryos require more nutrients to sustain their development. If you notice that your dog is suddenly eating more than usual, it could be a sign that she is pregnant.

Weight Gain

Another physical indicator of pregnancy is weight gain. As the embryos develop and grow, your dog’s body will start to change to accommodate them. This can result in a noticeable increase in weight. However, it’s important to note that other factors, such as overfeeding or lack of exercise can also cause weight gain.

Enlarged Nipples

As the pregnancy progresses, your dog’s nipples will start to enlarge and become more prominent. This is because they are preparing to produce milk for the puppies. You may also notice that the skin around the nipples becomes darker in color.

Enlarged Abdomen

The abdomen will gradually expand throughout the pregnancy. It will become more evident as the puppies continue to grow inside the uterus.

It’s important to remember that these physical indicators of pregnancy are not foolproof, and other factors can cause them. A veterinary examination or ultrasound is the most reliable way to determine if a dog is pregnant.

What Could Make A Dog Mating Unsuccessful?

The success of dog mating can be influenced by a variety of factors that involve both physiological and behavioral aspects. According to Malcolm Weir, DVM, Female dogs typically begin their heat cycles by the age of two and should experience them at regular intervals thereafter. 

However, some dogs may suffer from abnormal estrous cycles characterized by delays, absences, or irregularities. Conditions like primary and secondary persistent anestrus, which involve a lack of cycling, can be influenced by factors such as malnutrition, medication, and systemic diseases like renal failure and hypothyroidism.

Behavioral issues like a dominant female refusing a submissive male or an unpleasant breeding environment can also hinder successful copulation. Physical factors causing pain, such as vaginal abnormalities or osteoarthritis, may also lead to an unwillingness to mate.

To determine the cause of infertility, veterinarians typically conduct a range of tests, from blood work to hormone assays and imaging. Treatment for infertility varies according to the diagnosis and may include surgical procedures, hormonal treatments, and medication. Timely breeding based on hormone levels and offering a stress-free environment can also help improve the chances of successful mating and conception.

If a dog does conceive, pregnancy loss can occur due to hormonal imbalances, medications, or infections. Therefore, addressing these underlying issues is crucial for successful mating and pregnancy.

Infertility In Male Dogs When A Mating Is Unsuccessful

Infertility in Male Dogs

Infertility in male dogs can arise from a variety of factors and is generally classified into three main categories:

  1. Failure to Copulate or Ejaculate: Behavioral issues can sometimes prevent a male dog from successfully copulating. For instance, a male dog may be inexperienced or anxious, which could lead to failed attempts at mating. Physical limitations due to age, injury, or anatomical abnormalities may also impair the dog’s ability to copulate or ejaculate.
  2. Poor Semen Quality: Factors like age, diet, and underlying health conditions can influence the quality of a dog’s semen. Parameters like sperm count, motility, and morphology are critical for successful fertilization. Hormonal imbalances and genetic disorders can also contribute to subpar semen quality.
  3. Prostatic Disease: The prostate gland plays a significant role in male canine reproduction. Diseases of the prostate such as prostatitis (inflammation of the prostate), benign prostatic hyperplasia, and prostate cancer can severely impact a male dog’s fertility. These conditions can lead to painful ejaculation, blood in the semen, or even complete obstruction of the ejaculatory ducts.

If a male dog is suspected to be infertile, a thorough veterinary examination is crucial. This may include semen analysis, hormone tests, and ultrasound imaging of the reproductive tract. Treatment is tailored to the specific cause of infertility and may include medications, hormone therapies, or even surgical intervention in severe cases.

How Do You Ensure a Successful Dog Mating?

Breeding dogs can be a complex process, and it is essential to ensure that a mating is successful. Here are some tips to help ensure a successful dog mating:


Timing is crucial when it comes to dog mating. Female dogs are only receptive to mating during a specific time of their reproductive cycle, known as the estrus cycle.

It is important to determine when the female is in heat to ensure the mating occurs at the right time. A veterinarian can help determine the timing of the estrus cycle.


Before mating, it is important to prepare both the male and female dogs. The female dog should be in good health and at the right age for breeding. The male dog should also be healthy and free from any genetic disorders that could be passed on to the offspring.


The environment in which the mating takes place can also play a role in its success. The dogs should be introduced in a neutral location, away from any distractions or other dogs. The area should be clean and free from any potential hazards.


It is vital to observe the mating process to ensure that it is successful. The male dog should be able to mount the female dog and achieve penetration. The dogs should remain locked together for several minutes, indicating that the mating has been successful.

Post-Mating Care

After mating, it is essential to provide the female dog with proper care to ensure a successful pregnancy. This includes providing a healthy diet, regular exercise, and monitoring for any signs of illness or complications. 

By following these tips, breeders can increase the likelihood of a successful dog mating and healthy offspring.

Veterinary Confirmation

When it comes to confirming a successful mating in dogs, veterinary confirmation is the most reliable method. There are several ways veterinarians can confirm whether a dog has successfully mated, including ultrasound scans, X-rays, and hormone tests.

Ultrasound Scan

An ultrasound scan is a non-invasive way to confirm pregnancy in dogs. It can be performed as early as 25 days after mating. During the scan, the veterinarian will look for the presence of gestational sacs in the uterus. If the gestational sacs are present, it is a clear indication that the mating was successful.


An X-ray can confirm pregnancy in dogs after 45 days of mating. During the X-ray, the veterinarian will look for fetal skeletons in the uterus. If fetal skeletons are present, it is a clear indication that the mating was successful.

Hormone Tests

Hormone tests can also be used to confirm pregnancy in dogs. These tests measure the levels of progesterone in the blood. Progesterone levels rise during pregnancy, and a sudden drop in levels can indicate that the dog has given birth. Hormone tests can be performed as early as 21 days after mating.

Overall, veterinary confirmation is the most reliable way to confirm whether a dog has successfully mated. Ultrasound scans, X-rays, and hormone tests are all effective methods that can be used to confirm pregnancy in dogs.

Frequently Asked Questions (FAQs)

What are the signs of a successful dog mating?

The signs of a successful dog mating can vary but usually include the male mounting the female and often locking with her. It is important to note that not all successful matings result in pregnancy.

How long after mating can you tell if a dog is pregnant?

It can take up to 2-3 weeks after mating for a veterinarian to confirm a dog’s pregnancy through ultrasound or blood test. However, physical signs of pregnancy, such as a swollen belly, increased appetite, and behavioral changes, may not be apparent until several weeks later.

What should I expect from my male dog after mating?

Immediately following a successful mating, the male dog may remain locked to the female for a period known as the tie, which can last from a few minutes to half an hour. During this time, he may appear tense or restless. Once the tie is broken, he might show disinterest in further mating attempts and focus more on normal activities.

Can a dog get pregnant after one tie?

A female dog can get pregnant after just one tie, but it is not guaranteed. It is recommended to allow for multiple matings to increase the chances of a successful pregnancy if you intend to breed your dog and you are an ethical breeder.

What is the dog mating process?

The dog mating process starts with the male mounting the female and penetrating her. The male then typically stays locked to the female for several minutes while ejaculating. After the mating, the male and female may separate and go about their normal activities. It is important to supervise the dogs during the mating process to ensure safety and prevent injury.

Final Thoughts

Determining whether a dog mating is successful can be a challenging task. However, by observing the physical signs like pregnancy and behavioral signs, one can determine whether the mating was successful or not.

Meet Your Experts

Avatar of author

Tamsin De La Harpe


Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.

Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.