Ask the Vet; Can a Neutered Dog Impregnate a Female Dog?
Whether a male dog can impregnate a female dog after being neutered is an important question.
After all, isn't the main purpose of neutering, preventing the numbers of unwanted litters?
Although dogs aren't as prolific as cats, their numbers can increase dramatically if we would allow nature to run its course.
For instance, consider that just one intact female dog and her descendants can potentially produce as many as 67,000 dogs in just six years!
In this article, veterinarian Dr. Ivana Crnec explains whether a male dog can impregnate a female dog after being neutered.
The Benefits of Neutering Dogs
We are all very well aware of the benefits of having our dogs fixed. Whether talking about spaying or neutering, the advantages are beyond worthy – from prolonging the lifespan, and reducing the risk of reproductive issues, to better behavior and enhanced training responsiveness.
However, the most important part of having our dogs fixed is controlling the overpopulation and consequently reducing the number of homeless and stray dogs.
Generally speaking, neutering has both medical and behavioral advantages.
Neutering not only prolongs the lifespan, but it also enhances the quality of life.
For example, neutered dogs are less likely to get seriously injured in dog fights. Additionally, neutered dogs are usually more responsive to their owner’s commands and they are easier when it comes to obedience training.
As a result, the risks from roaming behavior are, if not eliminated, at least significantly reduced.
Neutering is a surgical procedure.
Alternatively, there are other birth control methods such as anti-fertility vaccines and hormone drugs. However, those methods are all under investigation as yet none have been found to be both safe and reliable.
On a long-term basis, neutering can safely be performed on dogs as young as seven weeks of age. However, some vets have personal and unwarranted reservations about neutering before a dog reaches sexual maturity.
Understanding The Neutering Procedure
As previously stated, neutering is a surgical procedure.
Although more commonly known as castration, its exact scientific or medical term is orchiectomy.
The procedure got its name from the Latin words "orkhi," which means testicle, and "ectomy" which means cutting.
Simply put, neutering, as a surgical procedure is a routine operation performed under general anesthesia.
In a nutshell, the procedure involves removing both testes.
Once the operating field is clipped and disinfected, two parallel incisions are made on the scrotal sac (in front of each testicle). Then the testicles are removed while leaving the scrotal sac intact.
Alternatively, the incision can be made above the scrotal sac (pre-scrotal method).
In that case, both testicles are removed from the same incision and then the incision’s layers are properly sutured. During the post-op period, neutered dogs require suitable pain killers.
Ultimately, the removal of the testes results in:
1) Stopping the process of sperm production
2) Reducing the rate of male hormones (testosterone) production.
How Does Neutering Change Dogs?
Castration ultimately results in the loss of many male characteristics such as marking with urine, aggression towards other males and straying after female dogs in heat.
It also contributes to stopping young dogs from attempting to mount people’s legs.
Simply put, castration prevents all forms of unwanted hormone-induced sexual behaviors (roaming, attraction to females, humping, mounting and masturbating).
However, it is a popular misconception that castration calms down easily excitable dogs.
In fact, castration influences only the hormone-driven behaviors. Those behaviors do not magically stop after the procedure. Instead they slowly diminish over a period of several weeks.
It should be well-noted that castrating dogs does not prevent some rare forms of prostate cancer, but it does reduce the risk of the more common prostatic hyperplasia and testicular tumors. Additionally, castration reduces the risk of developing perianal tumors and hernias.
Are Neutered Dogs Still Interested in Female Dogs?
Well, this is a rather tricky question.
A few years ago, I neutered a 4-year old Pekingese dog named Pako. The surgery went smoothly and Pako was discharged and sent to spend the night at home.
The following morning, Pako’s mom called to tell me that our recently fixed Pako is now tied with the neighbor’s Maltese dog!
This old case of mine pretty much answers the above stated question. Simply put, yes, castrated dogs can still have sex.
Theoretically and practically speaking, a castrated dog can get aroused, experience an erection and tie with a female in heat.
With that being explained, it should be emphasized that not all castrated dogs will want to have sex.
When the testosterone levels fall down, the dog’s libido decreases as well. However, certain dogs' libido seems unaltered by the neutering procedure.
"A female dog in estrus is an extremely stimulating thing for any male dog, neutered or intact, and mounting and breeding behaviors can still happen." Veterinarian Dr. Matt
Can a Dog Impregnate a Female Dog After Being Neutered?
The statement that neutered dogs can still be sexually driven gives place for proposing another, even more important question – can a neutered dog successfully impregnate a receptive female?
The answer to this question is even trickier and it depends on how long ago was the dog neutered.
Generally speaking, a recently fixed dog can still breed a receptive female. This is because the testicles are not the only place where active sperm is stored.
In fact, viable sperm can be found in several storage places of the male reproductive system.
Theoretically speaking, the sperm may survive in those storage places for as long as 1 month. Practically speaking, the sperm remains viable for several days. This phenomenon is known as "dormant sperm."
From the above stated, it is safe to assume that, if it has been less than a month since the dog was castrated, it is still capable of breeding.
On the other hand, if it has been more than a month since the neutering procedure, the dog can have sex, but it will not be able to impregnate its partner.
All in all, the entire adventure will not result with a pregnancy.
The take home message would be that, in terms of having babies, neutered dogs can have safe sex as long as 1 month has passed since the neutering procedure. However, the sex is not safe in terms of transmitting certain infectious diseases.
How Long Should Neutered Dogs be Kept Away From Females in Heat?
In castrated males, the levels of testosterone start falling down within eight hours.
However, certain amounts of testosterone remain in the system for several months.
Another thing that remains in the system is the already created sperm.
Namely, the sperm that was created and stored in the reproductive tract may remain active and even viable for as up to 1 month.
In some literature, it is stated that neutered dogs can be fertile for as much as 6 weeks post neutering!
Generally though, one month after the neutering, the stored sperm in no longer viable, and since the testicles are removed, the storage cannot be replenished.
Additionally, one month after the procedure, the testosterone levels significantly drop which decreases the sex drive thus reducing the odds of having your castrated male breed with a female.
"We were taught in veterinary school that mature sperm can potentially be stored in the epididymis for up to one month on dogs, especially dogs who are already sexually mature. I have seen female dogs become pregnant who have tied with a dog who was neutered only a day or two prior to the tie. "~Dr. Angela, veterinarian
This article was published Mar 27, 2020 at 6:03 PM
For Further Reading:
An Exception to the Rule, Dogs With Retained Testicles
A neutered dog should not be capable of impregnating a female dog is a full month (or 6 weeks to be extra cautious) have passed.
However, there is an exception, but this is rather rare and a vet would have informed you about the issue upon neutering.
The exception to this would if a dog had a retained testicle and the vet removed only the one in the scrotum, therefore leaving the other one free to produce testosterone and sperm.
With a retained testicle left in the dog's abdomen the chances though for a pregnancy may not be that high considering that sperm stored there will be subjected to higher temperatures and we know that sperm develops better at lower temperatures.
However, it's not impossible, for a dog with a retained testicle to get a dog pregnant, observes veterinarian Dr. Ellie.
Discover more about dogs with retained testicles: help, my dog has only one testicle.
The Risk for Brucellosis-A Sexually Transmitted Disease
Even if your neutered dog cannot get a female dog pregnant after 1 month, there are still some risks associated in allowing him to mate with a female dog.
One of them is a condition known as brucellosis.
Brucellosis is a sexually transmitted disease in dogs often caused by direct contact with infected body fluids from reproductive organs, but it can also be transmitted by exposure to nasal secretions, eye fluids, saliva, birth fluids, milk and urine.
This is a condition that is easier to prevent rather than treat, so am emphasis should be placed on the importance of yearly testing for brucella before breeding dogs and temporary isolation before introducing a new dog into a breeding facility. Here's more info about testing a dog for brucellosis.
Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice or behavioral advice. If your dog is acting sick or aggressive please consult with a qualified professional for proper diagnosis and treatment.
