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

Alternative birth control methods are available to prevent pregnancy in dogs, but the FDA hasn't approved any of them, and none are 100% effective.

Alternative birth control methods are available to prevent pregnancy in dogs, but the FDA hasn't approved any of them, and none are 100% effective.

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, where you live, and whether you want something that actually 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. An abortion pill (mifepristone) called Mifeprex or RU486 is also available in a few.

If you're scared (or just wondering) if your dog was impregnated, there are some steps you should take and information on medication you should know. I'll cover the following topics in this article.

In This Article:

  • Confirm That Your Dog Is Really Pregnant
  • What Birth Control Medicines Are Available to a Dog?
  • How Much Does It Cost to Give a Dog the Morning-After Pill?
  • Spaying vs. Other Alternatives
  • When to Spay

First, Confirm That Your Dog Is Really Pregnant

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 a while, and unless your dog was gone for about 30 minutes it is unlikely there was a 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 if she was gone long enough to be bred, your vet will then discuss options.

What Birth Control Medicines Are Available to a Dog?

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

Diethystilbesterol (DES) Tablets

If you take her in immediately, she can be treated with diethystilbesterol (DES) tablets for five days. This is the closest thing to a “morning-after pill” for dogs, but it may not always work.

DES Side Effects in Dogs

DES can cause serious side effects, each of which can lead to other complications.

  • Blood cell abnormalities
  • Uterine infections
  • Mammary tumor development

DES and ECP (Estradiol Cypionate) Injections

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.

ECP Side Effects in Dogs

  • Pyometra
  • Bone marrow suppression

Some research has shown that low doses are effective and do not cause these side effects.

Prostaglandin F2alpha

This is an injection that will cause the ovaries to stop producing the hormone to keep your dog pregnant.

Prostaglandin F2alpha Side Effects in Dogs

  • Vomiting
  • Diarrhea
  • Cramps

This treatment is not recommended for dogs with heart or respiratory problems.

RU486

RU486, also known as misoprostol, 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.

RU486 Side Effects in Dogs

  • Vomiting
  • Diarrhea
  • Gas
  • Seizures

Dexamethasone Tablets

Dexeamethasone can cause abortion in dogs later in pregnancy.

Dexamethasone Side Effects in Dogs

  • Excessive thirst
  • Excessive urination
  • Vomiting
  • Diarrhea
  • Elevated fat or liver enzymes

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. If the drugs have not worked, she may need to be given something else.

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 was a lot more common. No one spoke to me about the alternatives and had I realized the side effects of the medication, I would have just found homes for the puppies.

How Much Does It Cost to Give a Dog the Morning-After Pill?

The cost of the medication to cause a dog to lose her puppies will vary depending on what is available.

One of the most reliable, prostaglandin, will need to be given by injection, and since several visits will be necessary, it can be quite expensive. It is not unusual for the injections to cost several hundred dollars, as much as having your dog spayed.

The most affordable of the options is dexamethasone. The medication is not given the day after, usually after a dog has been pregnant for 30 to 40 days, and there are side effects (like excessive water consumption and urination), but they are temporary. Unfortunately, if the owner stops giving the pills before the nine to 10 days is over, the dog may end up giving birth later on.

If you talk to your regular veterinarian about getting a prescription for dexamethasone, your dog will still need to be examined. The cost of the pills varies, but a prescription is usually only around $20.

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 United States 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 purebred.

The "shelter excess," however, is because most of the dog breeds available are not the types people are looking for. Having papers does not mean a whole lot to a dog on his way to death row, but very few small fluffy dogs like Shih Tzus and Maltese are not adopted out.

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.

Questions?

If you have any questions about this article or any health issues with your dog be sure to send them to my Ask a Vet column at Pethelpful.com and I will be glad to help.

References

Fraser NS. Mismating Diagnosis and Protocols. Vet Clin North Am Small Anim Pract. 2018 Jul;48(4):605-615. https://pubmed.ncbi.nlm.nih.gov/29656772/

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. https://pubmed.ncbi.nlm.nih.gov/16466658/

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.. https://pubmed.ncbi.nlm.nih.gov/18540033/

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. https://pubmed.ncbi.nlm.nih.gov/1858244/

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. https://pubmed.ncbi.nlm.nih.gov/2313658/

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. https://pubmed.ncbi.nlm.nih.gov/3997637/

Wanke M, Loza ME, Monachesi N, Concannon P. Clinical use of dexamethasone for termination of unwanted pregnancy in dogs. J Reprod Fertil Suppl. 1997;51:233-8. PMID: 9404290. https://pubmed.ncbi.nlm.nih.gov/9404290/

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?