AUGUST 2021 - DUE TO COVID-19 LIMITING SPAY/NEUTER SURGERIES, ALLEY CAT ALLIES AND THE ALLIANCE FOR CONTRACEPTION IN CATS AND DOGS NOW ENDORSE THE SHORT TERM USE OF MA TO PREVENT PREGNANCIES IN CATS- SEE THEIR WEBSITES FOR MORE INFORMATION
Edible Birth Control for Cats
It works, is low risk, *LOW COST,
and can save millions of cats' lives.
It works -
and can save millions of cats' lives.
This blog is my opinion based on years of personal experience and dozens of hours of research. I am not a veterinarian. Megestrol Acetate is available by prescription only in the United States but can sometimes be purchased on EBAY under the name "Nonovulin" and through an online retailer named Venivet. Do thorough research and give careful consideration before making your own decision about obtaining or using Megestrol Acetate.
It works -
I have used both Feralstat and Nonovulin with success for over 10 years. A colleague writes about his positive experience on Birthcontrolforcats.com. Fairchild Feral Friends has used it for over a decade to stabilize colonies while T/N/R is being done. A Topix forum (please see archived posts) has caretakers from all over the country discussing their success. And it has been available without a prescription in pharmacies in Europe for more than 20 years.
It's low risk -
The following French study took place after a consumer voiced concerns about side effects of megestrol acetate products for cat birth control. Even though the manufacturer's recommended dosage is much higher than the dose U.S. feral cat caretakers use, risk of side effects was determined to be .074 per 100K pills sold. An English translation as well as the original French study is available through the birthcontrolforcats.com website at http://www.birthcontrolforcats.com/cnpv.pdf
My own research (see archive) showed very little research in the U.S., and all at much higher doses. A European study was more extensive and showed very low risk of adverse reaction.
Along with my feral colony, I have used Nonovulin successfully on two indoor cats for which surgery was high risk, with no negative side effects.
It's low cost
July of 2020 I paid $16 for 30 ten mg Nonovulin pills through an EBAY vendor. My colony is currently 7 cats and my weekly birth control cost is 27 cents.
Nonovulin is a megestrol acetate product available in pharmacies in Europe without a prescription. In the U.S. megestrol acetate is prescription only through veterinarians.
My Colony
When I began feeding and dosing in September of 2019 there were 17 cats. There are now 7. There have been no births. I've used the chart below to determine dosage. I cut the 10 mg pills with a pill cutter and dissolve the dosage in a little water in a clear container so that I can see that the particles are well dissolved before adding them to one 22 oz can of wet cat food.
When I began feeding and dosing in September of 2019 there were 17 cats. There are now 7. There have been no births. I've used the chart below to determine dosage. I cut the 10 mg pills with a pill cutter and dissolve the dosage in a little water in a clear container so that I can see that the particles are well dissolved before adding them to one 22 oz can of wet cat food.
Please note that the dosage is PER COLONY NOT PER CAT.
Dosage PER COLONY using Nonovulin 10 mg tablets
Total # of Cats Dosage (dry) per colony
< 5 cats 2.5 mg ONCE a week
5-7 cats 5 mg ONCE a week
8-11 cats 7.5 mg ONCE a week
12-15 cats 5 mg TWICE A WEEK
16-19 cats 7.5 mg TWICE A WEEK
20-23 cats 8 mg TWICE A WEEK
24-27 cats 10 mg TWICE A WEEK
28-31 cats 11 mg TWICE A WEEK
32-35 cats 12.5 mg TWICE A WEEKc
2.8 ml TWICE A WEEK 14 mg TWICE A WEEK
This information was previously published on my site floridacatnews.com.
