Price Comparisons for estradiol



Estradiol is a prescription estrogen (estradiol cypionate) used to induce estrus (start the heat cycle) in horses. In the past it was used to prevent pregnancy (mis-mate shot) in dogs and cats, and to treat urinary incontinence, but is generally not recommended for those purposes now since other therapies are available.

For: Horses, and rarely for dogs and cats due to its toxicity.


Estradiol is the prescription estrogen, estradiol cypionate.

How it works: Estradiol is an estrogen, which is a hormone that when elevated induces (starts) estrus in horses. 

Dosage & Administration: Estradiol is given by mouth. Always follow the dosage instructions provided by your veterinarian. If you have difficulty giving the medication, contact your veterinarian. This medication should only be given to the horse/pet for whom it was prescribed.

Possible side effects of Estradiol: Side effects are not common when used in horses. When used in cats and dogs, side effects can be very serious and even life-threatening. May see lack of appetite, vomiting, diarrhea, vaginal discharge, pyometra (infection in the uterus), lethargy, increased thirst and urination, bone marrow suppression, aplastic anemia, bleeding, and death. Use in males may cause feminization.

If you overdose the pet: If you know or suspect your horse has had an overdose, contact your veterinarian immediately.

Keep this and all other medications out of the reach of children and pets.

What should I avoid while giving Estradiol to my pet: Consult your veterinarian before using ECP with vitamins and supplements, rifampin, phenobarbital, phenylbutazone, corticosteroids, or oral anticoagulants (such as warfarin), since interactions may occur.

Who should not take it? Not for use in animals hypersensitive (allergic) to it or drugs similar to it. Do not use in pregnant or lactating animals (female animals nursing their young). It can cause abortions and birth defects. Do not use in animals with cancers that may be caused by estrogens such as mammary (breast) cancer. Do not use in animals with bone marrow suppression. Do not use in males that are to be used for breeding.

Estrodiol can cause significant adverse side effects in cats and dogs and is generally not recommended for use in those species.