What is Alizin?

Alizin® is a synthetic progesterone antagonist manufactured by Virbac, used to induce abortion in dogs after unwanted matings and for treatment of Pyometra. The drug has been widely used and claimed to be safe and effective, with a fast and simple termination of pregnancy. However, some anecdotal evidence has raised concerns with our customers about potential lingering effects and adverse reactions. In this article, we will explore how Alizin works, its claimed properties and benefits, clinical trial results, and possible side effects.

How Alizin Works.

Alizin is a progesterone receptor antagonist, meaning it binds to progesterone receptors in the body and blocks their action. Progesterone is a hormone essential for maintaining pregnancy by supporting the development of the uterine lining and preventing uterine contractions. By blocking progesterone signals, Alizin stops successful ovum implantation and inhibits the maintenance of pregnancy.

Key Properties and Benefits According to Virbac:

• Fast and Simple Termination: Alizin offers a quick and uncomplicated method for terminating unwanted pregnancies in dogs.

• Timing of Use: The drug can be administered from 0 to 45 days after mating, with abortion usually occurring 3 to 4 days after treatment but possibly taking up to 10 days.

• Non-Interference with future fertility: Alizin does not affect future gestations or fertility in dogs, allowing them to conceive normally after treatment.

Efficacy:

Clinical trials have demonstrated the drug’s effectiveness in terminating pregnancies. According to the manufacturer’s claims:

• Efficacy in trials conducted between Day 0 and Day 22 was between 97.4% and 100%.

• Efficacy in trials conducted between Day 23 and Day 45 was between 88.7% and 97.7%.

Safety Considerations:

The manufacturer and regulatory authorities have deemed Alizin safe for use. Reported side effects from field trials include:

• Anorexia (25%)
• Excitation (23%)
• Depression (21%)
• Vomiting (2%)
• Diarrhea (13%)

It is essential to consider these possible side effects while administering the drug, and we advise you to read both Virbac’s Information Sheet and DEFRA’s Summary Of Product Characteristics to fully understand the contraindications for yourself, in addition to always consulting thoroughly with your veterinary surgeon.

Customer Concerns.

After reading the description and contraindications, everything looks pretty straightforward and as you would expect from any other drug (there will always be side affects and you never know which dog will succumb to any one of them). However, recurring post-treatment symptoms that we have heard anecdotally are that Alizin does in fact affect fertility, that it takes an uncomfortable period of time for the embryo to terminate and that it also takes longer than expected for the embryonic tissue to clear from the uterus.

So far, there seem to be no long term studies that have been made or initiated to investigate any of these claims. There also appears to be no published data (that we can find) that gives a timeframe for “naturally occurring” asorption, making it impossible to compare whether Alizin abortions have a more prolonged process of bodily recalibration.

Based solely on Verbac’s claims/clinical trials and customer scans of post-Alizin abortion uteruses, we can speculate that perhaps the tissue appears to linger in cases where it has taken the outset of 10 days to terminate the pregnancy. It is also possible that owners are not made aware that it can take 10 days for the drug to take effect.

Concerning Alizin’s effect on long term fertility, it is simply impossible to ascertain if there is truth to these claims without clinical evidence. However, the current lack of evidence does not invalidate our customers’ experiences and suspicions; it just means that they haven’t been officially investigated yet.

We want your opinion!

Would you use Alizin? Have you already used it? What was your experience and do you have any concerns? Please contact us so that we can continue our investigation!