A Bright Future In the future spay/neuter surgery will be viewed as old fashioned. Cats and dogs will be sterilized by: eating a tasty treat being injected with a contraceptive vaccine getting a painless implant the size of a microchip This is not sci-fi, this is scientific technology that is already in use.  Neutersol (see below) is patented and FDA approved for general use.  Other contraceptive products like this are still in the lab and/or being field tested in the U.S.

Contraception is a non-surgical alternative to spay/neuter surgery that is less risky, less expensive and less stressful for the animal. Efforts to develop contraceptives for pets began in the 1960’s when “the pill” for women first became available. Today scientists are on the brink of making various forms (pill, vaccine and implant)  of dog and cat contraceptives available to the public.

Here are a few examples:

• Hormonal implants using reproductive hormones — GnRH and progestin — are already being used for cats and dogs in other countries such as Australia and New Zealand. Implants are easy to administer -- similar to placing a microchip under the skin.
• Contraceptive vaccines such as PZP, a protein (www.pzpinfo.org), and the GnRH hromone trigger immune reactions that  block conception. These vaccines have been used successfully to control wildlife and zoo animals and early work is very promising in cats and dogs.
• Neutersol is the first permanent injectible sterilant to be licensed for use on dogs in the U.S. It is currently licensed for use in the U.S. for chemical castration of puppies three to ten months of age. It is a zinc compound that is injected into the testes and causes a sclerosis (thickening of the membrane) that results in permanent sterilization. It is 99+% effective and very safe. In most cases, Neutersol can be administered without sedation. An ultra-thin insulin syringe is used to administer a single injection into each testicle;  patient discomfort is minimal. Neutersol took 20 years and millions of dollars to develop. It can be used in adult dogs and may ultimately be used in cats and kittens. For more information go to http://www.allourpets.com/canine/neuter-puppy.shtml.
• Virus-vectored and bacterium-vectored contraceptives are delivered in food and are ideal for feral cat colonies and feral dog groups. 

Michelle Meister-Weisbarth, a student at the Virginia-Maryland Regional College of Veterinary Medicine, has developed a genetically engineered bacterium that can be used as an oral contraceptive to control the unwanted cat population. Working with molecular biologist Dr. Stephen Boyle, she has developed a genetically engineered strain of Salmonella bacterium that can be used as a cat contraceptive.  Normally, Salmonella infections cause severe gastro-intestinal illness in animals. However, this genetically engineered strain of the bacterium, has been rendered benign. Additionally, the contraceptive has been chemically “piggybacked”  onto the Salmonella bacterium, so it does not cause disease but does prompt the cat’s immune system to produce antibodies that prevent the sperm from fertilizing the egg.  This oral contraceptive can be put in food for feral cats in the wild. It is safe for all cats (male and female) and does not adversely affect wildlife. For more details on oral cat contraceptive information go to this link. With pressure from the public, and with more funding, a variety of dog and cat contraceptives could be available for public use in as few as two years!  Join NOA in getting contraceptives out of the lab and into the field to prevent the birth of homeless puppies and kittens.