Stilboestrol Medication Guide: Information for Pet Owners

Schedule 4 (Prescription Only): Stilboestrol is a prescription medication registered for human use in Australia.

While there is currently no mass-produced commercial brand of this medication registered by the TGA or APVMA in Australia, it remains a legally recognised therapeutic substance. Veterinarians may prescribe Stilboestrol "off-label" to be prepared by a registered compounding pharmacy specifically for your pet.

Stilboestrol is a medication that your veterinarian may prescribe to help manage specific hormone-related conditions.

Veterinarians may prescribe this medication to support female dogs with hormone-responsive conditions. Because its use in pets is considered "off-label" in Australia, your veterinarian will determine the specific clinical application based on your pet's unique needs.

Stilboestrol is a synthetic oestrogen. It works by mimicking the effects of natural oestrogen hormones in the body. For urinary health, it helps increase urethral sphincter muscle tone, supporting the bladder's ability to hold urine effectively.

• Stilboestrol Tablets for Dogs: Usually available in very small doses (e.g., 1 mg), as pets often require very low amounts to achieve clinical results.
• Compounded Formulations: Because the required dose for dogs is often much lower than human doses, a veterinarian may prescribe a custom-strength liquid or capsule from a compounding pharmacy.

Your veterinarian will determine the correct dose based on your dog's weight and clinical history.

Oestrogens can be absorbed through the skin. Pregnant women, or women of childbearing age, should exercise extreme caution and wear gloves when handling Stilboestrol. Always wash your hands thoroughly after administering this medication.

Safety Parity Notice: While often used at low doses, Stilboestrol can have serious side effects that require close monitoring:

• Bone Marrow Suppression: This is a rare but very serious side effect where the body stops producing enough blood cells (Anemia or Leucopenia). Your veterinarian will likely require regular blood tests.
• Hormonal Changes: In some cases, signs of "heat" Oestrus) may occur, such as swelling of the vulva or attraction of male dogs.
• Digestive Upset: Some pets may experience mild nausea, vomiting, or changes in appetite.

This medication should generally not be used in the following circumstances:

• Pregnancy: This medication must not be used in pregnant animals or those intended for breeding.
• Specific Cancers: Generally not used in pets with oestrogen-dependent tumours (such as certain mammary cancers).

The following conditions require careful consideration and monitoring by your vet:

• Blood Monitoring: Regular "Full Blood Counts" (FBC) are essential to monitor for bone marrow changes during treatment.
• Male Dogs: Use with extreme caution in male dogs, as it can lead to feminisation and potential prostate issues.

• Temperature: Store at room temperature (ideally between 15°C and 30°C) in a dry area away from direct sunlight.
• Security: Keep the medication in its original child-resistant container and store it strictly out of reach of children and other animals.
• Moisture: Avoid storage in bathrooms or laundry areas, as high humidity can affect the stability of the medication.

How long does it take for Stilboestrol to work?
Many owners notice an improvement in bladder control within the first few days of treatment. However, it can take up to 7 to 14 days to reach the full clinical effect as the muscle tone in the urethral sphincter gradually improves.

Does my dog need to take Stilboestrol every day?
Initially, your veterinarian may prescribe a daily dose for a short period (a "loading dose"). Once the incontinence is controlled, most dogs are transitioned to a "maintenance dose," which is often given only two or three times per week.

Why does my vet need to do blood tests for this medication?
While rare, Stilboestrol can affect the bone marrow's ability to produce new blood cells. Regular blood tests Full Blood Counts) allow your veterinarian to monitor your dogʼs health and ensure the dose remains safe for long-term use.

Can Stilboestrol be used in male dogs?
It is rarely used in male dogs. In males, oestrogen can cause feminisation (such as mammary gland enlargement) and can lead to serious prostate complications. It is primarily prescribed for "spay incontinence" in female dogs.

What should I do if I am pregnant and need to give this medication?
Because Stilboestrol is a hormone that can be absorbed through human skin, pregnant women should avoid handling the tablets directly. It is recommended to wear gloves when administering the dose and to wash your hands thoroughly afterwards.

If your veterinarian has determined that Stilboestrol is appropriate for your pet and has issued a valid Australian prescription, you can fulfil it through our pharmacy service.

Learn more about VLP Pharmacy and the prescription ordering process medications like Stilboestrol.

Disclaimer: This information is for educational purposes only and does not replace professional veterinary advice. Always consult your veterinarian beforestarting any new medication for your pet.