Low dose Megestrol Acetate as edible birth control

I'd like to share that I used low dose megestrol acetate (MA) in wet cat food in a colony of cats here in Central Florida for over a year and there were no births or pregnancies. I dosed wet food once a week. Pregnancy is prevented after the second week.  

I did extensive research before trying "Feralstat" (brand name it was marketed under at the time) on the NIH PubMed site (what few studies I could find for cats and megestrol acetate) and the incidence of adverse effect appeared very low. With the data from the 2003 French study  -" COMMISSION NATIONALE DE PHARMACOVIGILANCE VETERINAIRE RAPPORT D’EXPERTISE DE PHARMACOVIGILANCE relatif à l’AVIS CNPV – 02 du 9/12/2003" I calculated that the risk of adverse reactions was .074 per 100K pills sold. (MA has been available in France for over a decade, through pharmacies, without a prescription.)

Megestrol Acetate can be (at the time of this post) purchased on EBay under the brand name "Nonovulin", or obtained through a US veterinarian with a prescription. 

Here is the chart I copied from a TNR group that has used MA for sometime.

I am so sorry I missed this post!  This is great information - thank you so much for sharing it!

I know Florida is way ahead of a lot of states with their attitude about TNR.  Please, keep us posted about your work.

thanks for this information i am gonna look into this ,  since i am in central west florida 

I sure am going to look into this.

Would it be considered baiting to put some cans out where the neighbors unfixed cats would find it ?  They have some nutty religious thing where fixing an animal is somehow unnatural. I'm sick and tired of the dead, starving and dead kittens we have to deal with. I have seriously considered trapping and fixing their cats. We aren't able to get any assistance.

They consider kittens and puppies fun toys for the kids.

Kittens Mom said:

I sure am going to look into this.
Would it be considered baiting to put some cans out where the neighbors unfixed cats would find it ?  They have some nutty religious thing where fixing an animal is somehow unnatural. I'm sick and tired of the dead, starving and dead kittens we have to deal with. I have seriously considered trapping and fixing their cats. We aren't able to get any assistance.
They consider kittens and puppies fun toys for the kids.

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Unless I know the owner, when a cat comes into my yard, I trap and fix it. I had a neighbor similar to yours and he is the reason I have had to find homes for 54 cats and kittens and bury five. Plus three of my own eight cats come from his litters. Another neighbor now has a stabilized colony of 35 to 40 cats because she took on the TNR challenge.

I doubt seriously they will even be able to tell the females have been fixed, especially if you recuperate them for a week or so. They may be able to tell about the boys but I wonder if they'll even look.

This medication sounds like the answer to your prayers. You will want to think hard about this, though. You might be setting things up - if you start feeding them, these kitties may decide to make your yard their home, especially if their yard is getting over crowded.

Ondine said:

Unless I know the owner, when a cat comes into my yard, I trap and fix it. I had a neighbor similar to yours and he is the reason I have had to find homes for 54 cats and kittens and bury five. Plus three of my own eight cats come from his litters. Another neighbor now has a stabilized colony of 35 to 40 cats because she took on the TNR challenge.

I doubt seriously they will even be able to tell the females have been fixed, especially if you recuperate them for a week or so. They may be able to tell about the boys but I wonder if they'll even look.

This medication sounds like the answer to your prayers. You will want to think hard about this, though. You might be setting things up - if you start feeding them, these kitties may decide to make your yard their home, especially if their yard is getting over crowded.

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It's a little over 200 dollars each to fix them. More infuriating because of their income level they could get it done for free. Once they agreed to allow us to fix their female cats , between the rescue and us we had it set up that all they had to do was sign the papers and they would get their cats back fixed. It was all pretty matter of fact I wasn't marching for animal rights on them.

The way the man of the house explained it. When one cat goes away, ( dies, gets killed) another one comes along. I can sneak fix their cats. I can't fix that.

Our AC laws which are fairly new out here gain a bit more traction with every revision.

I look forward to the day my neighbors and ones like yours get shut down.

Kittens Mom said:

The way the man of the house explained it. When one cat goes away, ( dies, gets killed) another one comes along. I can sneak fix their cats. I can't fix that.

Our AC laws which are fairly new out here gain a bit more traction with every revision.

I look forward to the day my neighbors and ones like yours get shut down.

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Sadly, in a way, he's right - unless the cats are fixed!  It is such a common sense thing, I can't figure out why people don't get it.

My neighbor loved kittens and would socialize them beautifully.  But once they were 12 weeks old and the "Free Kittens" sign didn't work, he'd turn them out.  My other neighbor and I begged him to have his queen fixed but he said she was his baby and he didn't want her to hate him.  So he basically sent all her kittens out to fend for themselves!  People are sometimes too weird for me.

$200 is a lot of money for S/N.  Isn't there some sort of clinic or other low cost option?  I travel 35 miles for a $45 spay/$30 neuter clinic.  Thankfully, all our hard work has paid off.  We haven't seen any new wandering cats since the neighbor's queen died and he decided to keep a male, whom he promptly had fixed!  Go figure!

Ondine said:

 
Sadly, in a way, he's right - unless the cats are fixed!  It is such a common sense thing, I can't figure out why people don't get it.

My neighbor loved kittens and would socialize them beautifully.  But once they were 12 weeks old and the "Free Kittens" sign didn't work, he'd turn them out.  My other neighbor and I begged him to have his queen fixed but he said she was his baby and he didn't want her to hate him.  So he basically sent all her kittens out to fend for themselves!  People are sometimes too weird for me.

$200 is a lot of money for S/N.  Isn't there some sort of clinic or other low cost option?  I travel 35 miles for a $45 spay/$30 neuter clinic.  Thankfully, all our hard work has paid off.  We haven't seen any new wandering cats since the neighbor's queen died and he decided to keep a male, whom he promptly had fixed!  Go figure!

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Income wise we don't qualify for any of the county programs. Between the shots, exam and the spay it works out around 225. We're lucky if they run a road grader out her once a year. It's a work i progress here. Not so long ago there wasn't even a county shelter.

You're very welcome. I wish I could say that Florida is advanced as far as T/N/R but I haven't found that to be the case.My county for example - Seminole- still wants nothing to do with T/N/R even with Orange County and the nationally known Care program right next-door. A local group finally took it upon themselves to open a low cost clinic for ferals, owned cats ,and dogs. Thank goodness for caring, dedicated people.   

You're welcome. Thanks for caring about ferals. 

My friend, I don't know if it's "baiting" but I've fixed other peoples animals before when they refused to. Not that I wasn't anxious during the whole process, but I was fed up with exactly what you mentioned.

I wouldn't be too excited about this birth control for cats, if one cat moves on or gets relocated somehow, with no one to dose her, she'd get pregnant. I am also worried this might not do anything to prevent uterine infections from lack of kittens, hormonal issues and reproductive cancer.  Also I've not heard of this nor read about it but is it safe for the male cats or effect them at all?

P.S. I also see you do rescue work, I'm not sure if you know of this but some places especially PetSmart are known for their charitable work and grants to needy cities and cats. I'll pull a few links for you.

Found this on Spay USA.org. not sure if they are still participating but its worth a shot. 

Seminole County:

OVEIDO, FL
SpayUSA Certificate Participating Veterinarian
Please fill out the referral form  or call us at (800) 248-7729 for more details and to obtain a certificate.

SPAY N SAVE
988 N. RONALD REAGAN BLVD
LONGWOOD, FL 32750
407-920-4894
OPEN TO ALL
http://spaynsave.org/news/51-spay-a-neuter-clinic

SPCA OF CENTRAL FLORIDA
2800 COUNTY HOME RD
SANFORD, FL 32773
407-323-8685
OPEN TO ALL
http://www.ohs-spca.org/

Statewide:

SPAY FLORIDA
www.spayflorida.org
888 772-9352
OPEN TO ALL MUST LIVE IN STATE

The Petsmart link only takes applications starting next year. https://www.petsmartcharities.org/pro/grants/spayneuter-grants/free-roaming-cat-spayneuter-grants

I'm not by any means trying to make you feel badly or anything of the sort. I am hoping to encourage the actual TNR and not other variations of it. I hope you'll find some of my  information helpful. Thank you for caring when so many wouldn't.

Yes, Spay N Save is the non-profit here in Seminole County that's opened a low cost clinic open to feral cats. The woman that runs the group has spent over 20 years helping feral cat caretakers find low cost spay/neuter. 

You're right, the megestrol acetate isn't a perfect solution. In higher doses a small percentage of male cats have developed mammary tumors and a small percentage have developed diabetes. And it is not effective on male cats.

But I still maintain (and this is after doing T/N/R and being a feral cat advocate for 30 years) that in areas where there are no low-cost services available, or where people are unwilling to have the cats they're feeding spayed and neutered, it's an option and better than doing nothing. 

There's a T/N/R group in Pennsylvania that makes MA available to their caretakers so they can stabilize large colonies until all the cats have been fixed. I spoke to the vet who runs that group and does all of the surgeries and she's never had a caretaker report a physical problem nor has she seem any evidence of MA related issues on the table. 

tnrmakessense said:

 
My friend, I don't know if it's "baiting" but I've fixed other peoples animals before when they refused to. Not that I wasn't anxious during the whole process, but I was fed up with exactly what you mentioned.

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We have a very low population right now. Two that I'm sure of. That's down from somewhere between 40-50 a few years ago. I believe there is someone else trapping feral cats and either releasing them or getting them homes. And I'm not about to tattle on that person.

A small controlled population of these cats can provide a great service in rodent control. We have some that have taken care of excess rabbit populations and even hunt snakes. Realistically taken to any shelter they would be put down. The only birds I've seen them decimate have been some pigeons that were turned loose, guess who, and that is fine by me. However like any cat ,house, outside or feral they need to be vaccinated and receive reasonable care. Shelter, water and some food source. I don't mind a few.

I have two female cats, spayed, hand raised. There is nothing I would have liked better than a kitten of my own from each of them. Of course the issue was always the other dozen that we had to rehome. You can't find homes for adorable well socialized kittens. It's an almost hopeless task to find homes for well socialized healthy animals.  We stopped breeding horses over a decade ago. I simply refuse to add to the cannon fodder going over the borders to slaughter. I somehow doubt finding a kitten will ever be impossible. It's not about fixing every cat on the planet. It's about responsible breeding practices.

If adding something to some food keeps the population low its a reasonable cost.