Aglepristone given on Days 1 and 2 post-presentation (within 45 days of the last mating) achieves pregnancy termination rates of approximately 94–99% when treatment is initiated in the first 3 weeks post-mating, dropping slightly to around 80–95% when used between days 22–45. Efficacy is confirmed by ultrasound 10–14 days after the second injection. If pregnancy is confirmed to continue, re-treatment or alternative management should be discussed with your vet.

In open pyometra (where the cervix is open), aglepristone at 10 mg/kg SC on Days 1, 2, and 8 combined with broad-spectrum antibiotics (commonly amoxicillin-clavulanate or enrofloxacin) can achieve clinical resolution in many cases. The drug blocks progesterone receptors, allowing cervical relaxation and uterine drainage. Response is monitored by ultrasound at Day 14. It is NOT appropriate for closed pyometra (emergency surgery is required). Success rates vary but are reported at 70–90% for cases selected appropriately by a vet.

Local injection site reactions are the most common side effect — including transient pain, swelling, or oedema at the injection site, which usually resolves within 24–48 hours. Some bitches experience mild vaginal discharge during the days following treatment (normal in pregnancy termination). Less commonly, vomiting or lethargy may occur. Severe systemic reactions are rare. The product should be warmed to body temperature before administration to reduce injection site discomfort. Split large volumes across multiple injection sites (maximum 5 mL per site).

Alizin (aglepristone) is licensed in the UK, EU, and several other countries but is NOT approved by the FDA and is therefore not commercially available in the United States. In the US, some veterinary schools or reproductive specialists may use it under import permits or compounding arrangements, but this is uncommon. In Australia, it has conditional approval. Always check your country’s regulatory status with your vet or a veterinary reproductive specialist.

Yes — aglepristone has no permanent effect on fertility. Bitches treated with Alizin for pregnancy termination typically return to normal oestrous cycles and can become pregnant in subsequent cycles. The next heat usually occurs 4–6 months after treatment. If the goal is to prevent future unwanted pregnancies, spaying (ovariohysterectomy) is the recommended long-term solution, and this conversation is best had with your vet following Alizin treatment if ongoing birth control is desired.

Alizin is a prescription-only medicine for administration by or under the direct supervision of a veterinarian. The reasons are medical and regulatory: the indication requires veterinary diagnosis and confirmation (ultrasound for pregnancy staging or pyometra classification); injection technique, site selection, and volume splitting require clinical training; and monitoring after treatment (for completed abortion or pyometra resolution, or for adverse reactions) requires veterinary involvement. It should never be purchased online and self-administered.