Kingsdale Quick Takes
• Diethylstilbestrol for dogs (DES) is a potent synthetic estrogen.
• Stops hormone-responsive urine incontinence in spayed females.
• It's dosed once daily for 3–7 days, then weekly or even less.
• 60–80% of dogs dry within a week; maintenance keeps them leak-free.
• Rare but serious risk: bone-marrow suppression, so watch pale gums; pregnant women should wear gloves when handling.
Have you noticed your dog leaking urine while sleeping? Diethylstilbestrol (DES) for dogs is a synthetic estrogen most commonly used to treat urinary incontinence in spayed female dogs. It works by strengthening the muscles that help control urination, especially when hormone levels drop after spaying. If your dog is leaking urine while resting or sleeping, DES may be one of the treatment options your vet recommends. In this article, I'll explain how DES works, how it’s given, potential side effects, and what alternatives are available.
What is Diethylstilbestrol (DES)?
Diethylstilbestrol, DES for short, is a common hormonal agent used to treat urinary incontinence in dogs and cats and has success rates of up to 80%.
Diethylstilbestrol works very quickly in dogs, where it absorbs quickly and reaches target concentrations in the blood within 1 hour.
DES tightens the bladder’s muscular sphincter, stopping most leaks within a week. We start with a brief daily course, then shift to a once-weekly pill that keeps accidents at bay, with rare side effects when we monitor closely. Let me walk you through how it works, safety tips, alternatives, and home care so you can choose the best plan for your best friend.
How does Diethylstilbestrol (DES) work in dogs?
DES works because it’s a synthetic estrogen, meaning it mimics the effects of your dog’s own natural estrogen to treat estrogen-responsive urinary incontinence.
The urethral sphincter has estrogen receptors that help keep urine in the bladder. The receptors target smooth muscle, which explains why the urinary incontinence only occurs during sleep.
By activating these receptors, DES helps restore muscle tone (urethral tone), so your dog can better control their bladder.
What's unique about estrogen-responsive urinary incontinence is that the sphincter that is being targeted is the one that is controlled unconsciously. This is why dogs will usually only have urinary incontinence during sleep, not while awake.
What are the potential side effects of Diethylstilbestrol (DES) in dogs?
Because diethylstilbestrol for dogs is a synthetic estrogen, I always begin with the lowest effective dose and keep a close eye on three main issues:
- Reversible alopecia: A few spayed female dogs develop patchy hair thinning on the flanks or tail. It’s cosmetic, not painful, and hair usually regrows once we taper the dose or pause the drug.
- Lethargy/Increased thirst and urination: Some dogs taking DES can show signs of lethargy, as well as increased thirst and urination.
- Male attraction: DES can make treated females smell attractive to intact male dogs and may even induce estrus when doses are very high. Please note that only intact male dogs (i.e., not neutered) will be susceptible.
- Bone marrow suppression: Rarely, DES interferes with the bone marrow, leading to serious side effects such as bone marrow toxicity, which can cause aplastic anemia or low platelet counts called thrombocytopenia. Falling white blood cells or platelet counts put your dog at risk for infection and bleeding. Symptoms of bone marrow toxicity may include weakness, fever, bleeding, and bloody diarrhea. Watch for pale gums, easy bruising, bloody urine or stool, or extreme fatigue. If you notice these symptoms, stop the medication and immediately contact your veterinarian.
Very rarely, DES might also trigger hormonal problems like cystic endometrial hyperplasia of the uterus, an infected uterus (pyometra), or encourage the growth of estrogen-sensitive tumors such as mammary tumors.
With all of this said, DES is a safe and well-tolerated medication when appropriate doses are used.
Guidelines and dosing of Diethylstilbestrol (DES) in dogs
When I prescribe diethylstilbestrol (DES) for dogs, I’ll usually start with a short, daily course to stop the urine leaking. Typically, this means giving an initial dose of 0.1 to 1 mg per dog once daily for about 3 to 7 days. If the dog’s urinary incontinence improves during this time, I’ll then adjust the dosing interval, usually to about 1 mg once per week, or less often if possible, to achieve the lowest effective dose.
Because DES isn’t available commercially, we have to obtain it from a veterinary compounding pharmacy, often as a tablet or compounded liquid made specifically for your dog.
When giving the medication (oral administration), please follow the instructions carefully on the prescription label, and pay close attention to medication administration intervals to maintain effectiveness. Be sure to follow the instructions on the prescription label for any other specific details.
You can offer diethylstilbestrol on an empty stomach or mixed with a meal; giving it alongside food usually lowers the chance of digestive upset, such as vomiting.
If you accidentally miss giving a dose, don’t double-up the next dose. Giving two doses at once can increase the risk of side effects. Instead, continue as scheduled, and let your veterinarian know if you have any concerns.
As with all medications, our goal is to control symptoms using the least amount necessary, reducing potential side effects and keeping your dog symptom-free.
What are alternatives to using Diethylstilbestrol (DES) in dogs?
Even though DES is usually the first medication to try to treat urinary incontinence, it’s not the only option.
One good alternative to DES is estriol. Estriol is another natural estrogen medication that’s commonly prescribed for urinary incontinence in dogs. It’s approved specifically for use in dogs in several countries and generally comes with fewer risks than other estrogens like DES.
Another medication we could try is phenylpropanolamine (PPA). This medication isn’t an estrogen but works differently by tightening the muscles around the urethra. In fact, combining these two medications, DES or estriol with PPA, often helps dogs who don’t fully respond to one medication alone.
Sometimes, pet owners ask me about natural remedies or herbal therapies. While these can occasionally help with mild symptoms, they’re usually less predictable and effective compared to prescription medications. Always inform your veterinarian about any other medications your dog is taking to avoid potential drug interactions. Please discuss with your veterinarian if any complementary treatments might be helpful for your dog.
What are the precautions for using DES in dogs?
Diethylstilbestrol isn’t recommended for dogs who are pregnant, nursing, or have estrogen-sensitive cancers, and should be used with extreme caution in these cases.
Due to human toxicity potential, this medication can pose risks to anyone trying to conceive, pregnant women, women who might become pregnant, and those who are breastfeeding. When handling DES, it is recommended to wear gloves and wash hands immediately after use to minimize any potential risks.
Diethylstilbestrol for dogs remains one of the most reliable ways to treat urinary incontinence in spayed female dogs, provided we use the lowest effective dose and monitor closely. This synthetic estrogen restores urethral tone quickly, which allows for better control of her bladder during sleep. It can be used long-term with the guidance of your veterinarian, and side effects are uncommon when using low doses. If you have any questions, please feel free to contact your veterinarian.