{"id":631616,"date":"2025-03-11T19:31:53","date_gmt":"2025-03-11T23:31:53","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=631616"},"modified":"2025-03-11T19:31:53","modified_gmt":"2025-03-11T23:31:53","slug":"estradiol-for-dogs","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/estradiol-for-dogs\/","title":{"rendered":"Can estradiol be used for dogs?"},"content":{"rendered":"

Estradiol<\/span><\/a> is a natural <\/span>estrogen<\/span><\/a> that produces female secondary sexual characteristics, regulates estrus cycles, prepares the body for pregnancy, and affects organs throughout the body. All mammals and most other animals produce estradiol.\u00a0<\/span><\/p>\n

Although estradiol is prescribed to women, veterinarians rarely use estradiol in animals other than female horses (mares). They consider it unsafe because of the risk of bone marrow suppression and uterus diseases. When dogs need estrogen treatment, <\/span>estriol<\/span><\/a> is the estrogen of choice.\u00a0<\/span><\/p>\n

RELATED: <\/b>Save up to 80% on estradiol<\/b><\/a><\/p>\n

What is estradiol used for in dogs?<\/span><\/h2>\n

Veterinarians largely avoid using estradiol in dogs. Estradiol (E2) is a natural hormone in dogs, but it\u2019s the most powerful type of estrogen. It also lasts a long time in a dog\u2019s body and can cause serious uterine diseases and suppress bone marrow. Estradiol-induced bone marrow suppression can be fatal in some cases.<\/span><\/p>\n

In addition to estradiol, dogs also naturally produce two other types of estrogens: estrone (E1) and estriol (E3). These are less powerful than estradiol and less likely to cause side effects. Estrone is the weakest, so it\u2019s not generally used in veterinary medicine. Estriol is powerful enough to treat estrogen-responsive problems. It\u2019s weak enough that serious problems are less of a concern. For this reason, estriol is the preferred estrogen treatment in veterinary medicine. It\u2019s also the only estrogen FDA-approved for use in dogs.<\/span><\/p>\n

That doesn\u2019t mean veterinarians can\u2019t use estradiol, but its use is discouraged in favor of safer treatments. The primary use of estrogens in veterinary medicine is to treat urinary incontinence in female dogs that have had their ovaries surgically removed. Veterinarians may also use an estrogen to terminate a pregnancy, but there are safer drugs for that purpose.<\/span><\/p>\n

Urinary incontinence<\/span><\/h3>\n

Canine urinary incontinence has many possible causes, including behavior problems, infections, and anatomical abnormalities. One common cause is a weak urethra sphincter. Called \u201cprimary sphincter mechanism incompetence\u201d or PSMI, a weak bladder sphincter isn\u2019t strong enough to hold back the pressure of urine in the bladder. It mainly affects female dogs after they\u2019ve been spayed, and their estrogen levels drop dramatically. About <\/span>1 in 5<\/span><\/a> spayed bitches eventually become incontinent. The incidence is higher in large dogs.<\/span><\/p>\n

Loss of estrogen causes several changes in a female dog\u2019s body, including gradual changes to the urethra. These changes make the dog less capable of holding back urine. This doesn\u2019t happen right after a spay. It usually takes two to three years after a spay before the dog shows signs of incontinence, such as house soiling.<\/span><\/p>\n

As a hormone replacement therapy, estrogens have been used in postmenopausal women to treat urinary incontinence. Estrogens also relieve incontinence in spayed dogs. Estrogen therapy relieves weak sphincter urinary incontinence in about 65% to 83% of dogs. So they work, but the danger of possible serious side effects in estradiol is a problem.\u00a0<\/span><\/p>\n

Among the various types of estrogen, estradiol is the least safe to use as a daily treatment in dogs. If estrogen treatment is appropriate, veterinarians use estriol instead. Veterinarians also use a drug called <\/span>phenylpropanolamine<\/span><\/a> to treat urinary incontinence.<\/span><\/p>\n

Is estradiol safe for dogs?<\/span><\/h2>\n

Estradiol is not considered safe for dogs, but veterinarians may, on rare occasions, use it. All estrogen treatment is risky in dogs, but estradiol is more likely to cause bone marrow suppression, blood disorders, and uterine diseases than other estrogens.\u00a0<\/span><\/p>\n

Bone marrow suppression usually reverses after estradiol is stopped, but not always. In rare cases, bone marrow suppression may persist and get worse after estradiol is stopped. A dog could lose the ability to make blood cells (aplastic anemia) and die.<\/span><\/p>\n

Side effects of estradiol in dogs<\/span><\/h3>\n

The most <\/span>common side effects<\/span><\/a> of estradiol and other estrogen treatments in dogs are:<\/span><\/p>\n