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Is There a Morning-After Pill Available for Dogs to Stop Pregnancy?

Dr. Mark is a veterinarian. He works mostly with dogs and exotic animals.

Alternative birth control methods are available to prevent pregnancy in dogs.

Alternative birth control methods are available to prevent pregnancy in dogs.

Plan B for Dogs: Does It Exist?

Is a pill available to halt a dog's pregnancy? Well, yes and no. It really depends on your veterinarian, on where you live, and whether or not you want something that works.

In humans, the type and effectiveness of the "morning-after pill” vary by country—it is the same thing with dogs. For humans, a progestin-only tablet that may work for up to 72 hours is available in most countries, and an abortion pill (mifepristone) called Mifeprex or RU486 is also available in a few.

When you take your dog to your vet, the first thing they should determine is whether the female is really pregnant. Keep in mind that it takes about 30 minutes for successful mating.

The vet will do vaginal cytology to find out if she is in heat—if she is in an early stage of heat but you tell him that she ran off several days ago, there is not much chance she was bred. If he sees sperm cells when looking at the cytology, she has obviously bred.

If the female is no longer in heat if sperm is found on the slide, successful breeding was seen, or she was gone long enough to be bred, your vet will discuss options.

What Birth Control Medicines Are Available to a Dog?

  1. If you take her in immediately, she can be treated with diethystilbesterol (DES) tablets for 5 days. This is the “morning-after pill” for dogs but it may not even work.
  2. If it is several days later, probably more than five days, DES will only work if it is given after an ECP (estradiol cypionate), the estrogen mismate injection. “Mismate” injections have had some side effects and are not available everywhere.
  3. Prostaglandin F2alpha is an injection that will cause the ovaries to stop producing the hormone to keep your dog pregnant.
  4. RU486 has been used, but it is not labeled for dogs and is also expensive. The drug is only effective in the second half of pregnancy, like dexamethasone, but does not have the recorded side effects.
  5. Dexamethasone tablets can cause abortion in dogs later in pregnancy. Side effects—excessive thirst and urination during treatment. There are no known permanent side effects.
  6. Other drugs are available in some countries.

No drug is approved by the FDA and none works 100% of the time. The vet needs to check your dog over the next few weeks to make sure she is not pregnant, and if the drugs have not worked, she may need to be given something else.

Side Effects

Side effects vary depending on which drug is used—most of them are serious!

  • DES may not work but can cause blood problems
  • ECP can cause pyometra and bone marrow suppression, although some research has shown that low doses are effective and do not have the side effects that were reported earlier
  • Prostaglandin F2alpha causes vomiting and cramps and is not recommended for dogs with heart or respiratory problems
  • Dexamethasone does not always work and may cause skin or GI problems

A long time ago, one of my Siberian Huskies was bred by a stray dog and I took her in for a mismate injection. Months later, I stood next to the cage and held her in my arms as she died of severe anemia and organ failure secondary to bone marrow suppression. At that time, the mismate injection DES was a lot more common. No one spoke to me about the alternatives.

Spaying vs. Other Alternatives

A note about breeding: Selling puppies is not really a good way to make money. Besides the costs of excess food and medications (like dewormers), a female may have problems whelping and require expensive veterinary care, such as a c-section. Some females do not produce enough milk and you will spend a lot of money bottle feeding the new puppies.

If you want to breed her so that the kids can see the “miracle of life,” you also need to know that according to the US humane society, about every 11 seconds a dog or cat dies in the US because of pet overpopulation. Getting your dog spayed now is the only way to prevent her from having a litter of puppies down the road.

Unless you are willing to take back and rehome every puppy you put out there, do not breed your dog.

If you think you need to keep her intact and produce a litter of puppies because she is purebred, you should be aware that about 25% of all dogs in the shelter are purebreds. Having papers does not mean a whole lot to a dog on his way to death row.

When to Spay

If you think your dog is pregnant and you really have no vital need to breed her in the future, take her in for a spay about two to three weeks after she goes out of heat. Dogs just coming out of heat bleed excessively and have problems during the spay. If it has been two weeks, even if she is bred her uterus should be small and the vet should not charge any extra. If you wait longer than this her uterus will be large and the surgery will be more difficult (and more expensive).

It will still be less traumatic than whelping!

Think about it.

When puppies are "accidental" (cross bred) it is not always easy to find them a home.

When puppies are "accidental" (cross bred) it is not always easy to find them a home.


Fraser NS. Mismating Diagnosis and Protocols. Vet Clin North Am Small Anim Pract. 2018 Jul;48(4):605-615.

Tsutsui T, Mizutani W, Hori T, Oishi K, Sugi Y, Kawakami E. Estradiol benzoate for preventing pregnancy in mismated dogs. Theriogenology. 2006 Oct;66(6-7):1568-72.

Whitehead ML. Risk of pyometra in bitches treated for mismating with low doses of oestradiol benzoate. Vet Rec. 2008 Jun 7;162(23):746-9..

Romagnoli SE, Cela M, Camillo F. Use of prostaglandin F2 alpha for early pregnancy termination in the mismated bitch. Vet Clin North Am Small Anim Pract. 1991 May;21(3):487-99.

Concannon PW, Yeager A, Frank D, Iyampillai A. Termination of pregnancy and induction of premature luteolysis by the antiprogestagen, mifepristone, in dogs. J Reprod Fertil. 1990 Jan;88(1):99-104.

Bowen RA, Olson PN, Behrendt MD, Wheeler SL, Husted PW, Nett TM. Efficacy and toxicity of estrogens commonly used to terminate canine pregnancy. J Am Vet Med Assoc. 1985 Apr 15;186(8):783-8.

More About Your Dogs Health...

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Questions & Answers

Question: I have an American bully. We have a selected male for her to be bred to but I saw a local mutt in my yard stuck to her. He jumped over the wall. What can I do to prevent her from breeding with other dogs, and can I still breed her to the selected male I had plans for?

Answer: You cannot do anything at this point, she is already bred. Call your local vet immediately and find out the options they have to abort the puppies if you do not want them. You cannot breed your dog this time around but in 6 months, when she is in heat again, you can keep her confined so that she will not be bred by a local dog, and then breed her to the dog that you have selected.

Question: I can not find a vet in Massachusetts to provide the DES - do you know any or can you tell me how to find the proper dosing?

Answer: Some vets will not sell the product because of the side effects. Other alternatives (like dexamethasone) are safer. Having your dog spayed is teh safest option. If you cannot find a source for the DES, the dose is not necessary.

Question: How can I tell at home if my dog is bred?

Answer: Here is an article you can read to look for some other signs at home:

Question: How can I stop the implantation of my Rottweiler who was just bred with a local dog?

Answer: You need to contact your local vet and find out what is available. Some countries no longer sell mismate injections, so ask what is available. If nothing is available, and you do not plan on breeding your Rottie in the future, having her spayed is the best option.

© 2013 Mark dos Anjos DVM


Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on April 21, 2019:

Samantha, the medication is available but with a prescription. You should get your dog spayed.

Samantha on April 20, 2019:

I dont want my dog to get pregnant but she has locked up with another dog. Can i give her a my way pill to keep her from getting pregnant?? I dont have the money to take her to the vet..

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on August 16, 2018:

Ayla, are you planning on using your dog for breeding later? If not, the best thing to do is have her spayed now, while her uterus is small.

You cannot diagnose the preganancy this early, but around 30 days she can have an ultrasound or a relaxin test. All vets, even in the US, have access to dexamethasone so can use that alternative if they are willing.

Ayla on August 16, 2018:

hello. my dog harley was let out by my parents last night, she jumped the fence and was gone for over four hours, she is a week and around three days into her second heat and has been licking at her privates ever since she came back, ever since i came back from school ive been looking for any vet offices that sell abortion pills/shots but cont find any so far, i live in america where mismate is not available and i dont know any places that would sell these products i have a couple brands such as Dinoprost and prostaglandi2alpha (heard this over phone with vet so may not be spelled correctly). is there any ways i can tell she is pregnant or can soon?

Caitlin Jones on July 26, 2018:

can a dog abortion happen?

my fur baby has had a round of puppies twice now and they just have not made it.

I am ashamed to say the least that my husband and I haven't gotten her in sooner to be spayed.

My husbands boy dog got into her sleeping area and had his way with her. I do not want to go through that with her again. Our oldest dog had major issues with her when she lost her last batch. Vet said it was because in a "pack" every dog has its role and apparently carmela didn't do her job when she lost her puppies. It was hard trying to get all my fur babies to get along again.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on March 05, 2018:

Kiley, how long ago was this?

Kiley on March 04, 2018:

I didn't know my dog was in heat because this was her first heat cycle and she was with her intact dad all day. I don't know what to do?

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on November 17, 2017:

Why terrified? Preventing the pregnancy, and what might be a difficult whepling, is the best thing you can do.

MissKay on November 16, 2017:

My dog is a chihuahua papillon mix, she’s 2, and my sisters beagle terrier mix he’s 8 months. He caught my dog, and I don’t know if she’s pregnant cause it just happened. I want to get her the mismate pill, but I’m terrified to give it to her. Also I have no money or a job.... so I’m frantic.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on November 09, 2017:

Ss--these drugs are not available over the counter in the US. Call your local vet´s office and ask what they have available.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on November 09, 2017:

Ss--these drugs are not available over the counter in the US. Call your local vet´s office and ask what they have available.

Ss on November 08, 2017:

My female just got mated this evening with a Stray accidentally ... the heat was almost over...What can I do to avoid the pregnancy ?

Ramesh Chandra Suryavanshi on August 05, 2017:

Kelly give him delvosteron injection to stop pregnancy..

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on August 04, 2017:

Kelly, talk to your vet about havin her spayed.

Kelly ellison on August 02, 2017:

My dog has been cought of a bigger dog and I'm frightened she might have trouble giving birth is there anything I can do to stop the pregnancy

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on March 09, 2017:

deya-monkey --there is no standard answer on how many visits. Many owners of pregnant dogs do not even bother going in, but at least once in late pregnancy is a good idea. If you are going to get the ultrasound, get it done kind of late in pregnancy, about 6 weeks, to evaluate how many puppies there are and how things are developing.

Sorry that happened, hope it all works out. (Hopefully you will find homes for the puppies. Start looking now.)

deya-monkey on March 09, 2017:

Dr Mark, so i have never been a fan of spraying my dogs.. but it was not my intention for them to mate.. my stud is 4 yrs half husky half pit.. and she is a pit mix of some sort 2 yrs.. yesterday while my bf was at work and i was out doing some things regarding my own pregnancy.. now not to point finger i will avoid how it happened, but the dogs were left alone for a lil over an hr loose in the house bc people do not like to respect or listen to what others tell them to do.. bottom line is they locked and there's no telling for how long.. i don't really have the money at the moment to deal with the vet pills for her to be pregnant.. but if she is then i would like her to have her puppys and i will keep one.. and find homes for the rest but making sure if something happens they come back to us..

how many appt do the vet usually request when the dog is pregnant? how far does she have to be to get an ultra sound? and any advice i would be more them happy to listen to..

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on March 07, 2017:

Steven, I just answered your question on HP. Yes, you can call your vet and arrange to have her treated with mismate but having her spayed is the best ultimate solution.

Steven on March 07, 2017:

My dog is in heat about a week,have been informed a dog might have breed with her by accident 4 days ago can I still use medication to terminate the pups, or would getting her spayed fix it

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on August 18, 2013:

A lot of the volunteers were doing "alterative sentences" (community service) but the boy who put the dogs in the gas chamber was an employee. I am sure he had nightmares. Small puppies went there immediately--they never even had a chance. Like you said, someone has to pay for selfishness.

LKMore01 on August 18, 2013:

Doing that kind of work would be the end of me. My soul would die. There would be nothing left of me to give any one after spending twenty minutes doing that job Dr. Mark. I know it has to be done and the people who do it are brave. They do care about animals. I know this. You know this. But who the hell would want to do that for a living? And yet we have to have skilled practioners who will kill them humanely because of our own selfishness.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on August 18, 2013:

That comment on "putting to sleep" is really true. Dogs are not sleeping, they are dead. It is not easy for some to accept, but it is true!

I know what you mean about the injections. Years ago I volunteered my time at a local humane society and they gassed dogs nearly every day. It was not humane.

LKMore01 on August 18, 2013:

Outstanding, Dr. Mark. Examining all the alternatives to solve the pet overpopulation crisis. Overpopulation is a stunning problem in this world. Imagine working at a shelter where you have to inject perfectly healthy dogs and cats with poison and KILL them . "Putting to sleep" is a term that needs to be abolished. We are literally killing millions of animals every year because we are not taking responsibility for their spaying and neutering. Thank you. Voted up and sharing.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on July 21, 2013:

I will read it as soon as you publish. I am not a fan of crate training but am not the sort of person who always has to be right, either. It is good to hear other experiences, and, as you know, dogs are individuals and you can't treat them all the same.

Mom Thoughts on July 21, 2013:

DrMark, I am hoping to write more on dogs. We recently started crate training her as a last resort when she would not stop chewing our faux leather couch. It turns out she actually loves her crate and will go in there without us telling her too when she wants some alone time. I am hoping to write an article about that soon.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on July 20, 2013:

Thanks, MomThoughts. I read your hub on the Sporn harness last week when you published. Are you planning on writing more about dogs?

Writer Fox, I appreciate those words. It was a long time ago but even now I wish someone had just talked me into having her spayed.

Writer Fox from the wadi near the little river on July 20, 2013:

So sorry you lost your pet. I think you give some great insight into this topic and I hope many people will find your article here. Voted up!

Mom Thoughts on July 20, 2013:

I want to say I love the title of this Hub. It causes a reader to stop in her tracks with interest and click the link to read it.

As a new dog owner who recently adopted a dog from my local SPCA I am a huge believer in getting animals spayed and neutered. Enter any animal shelter and you will see the results of owners choosing not to get their animals fixed. There are so many beautiful animals getting put down because of overpopulation and it would not be happening if owners would just get their dogs and cats spayed or neutered.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on July 18, 2013:

That "barepawed and prego" philosophy was all too common where I used to live. When puppies sell for $1000, a lot of people really do think they can make money at it.

Thanks for stopping by and commenting!

Bob Bamberg on July 17, 2013:

Ditto. Your info and cautions are most valuable.

In my area, leash laws exist and owners are all but ostracized if they don't have their dog or cat altered, so it may seen a bit odd, but a hub like this is a reality check for me.

I forget that elsewhere, people see ads for puppies selling for hundreds or even thousands of dollars and figure, "Hell, I'll just get me one of them puppy machines, keep her barepawed and prego, and make me a ton of money." Others are just careless or neglectful and accidents happen.

Good and important hub! Voted up, useful and interesting.

Mark dos Anjos DVM (author) from The Atlantic Rain Forest, Brazil on July 17, 2013:

We cannot drive that point home often enough!

Elizabeth Parker from Las Vegas, NV on July 17, 2013:

Thank you for this wonderful and informational hub. I'm so glad that you addressed the population of dogs on death row and how many are purebreds. It's a point I always try to drive home as well. Voted this up.