A new contraceptive implant for canines offers the advantages of castration without surgery.
Now available in commercial quantities in Australia and New Zealand,
Suprelorin, the world's first pet contraceptive, is implanted under the skin between the shoulders to reduce a male dog's testosterone levels to zero and cease reproductive function for six months. Inserted with an implanter similar to those used for
micro-chipping, Suprelorin slowly releases deslorelin, a hormone similar to those used to treat human prostate cancer. The low, continuous dose of deslorelin prevents the production of sex hormones. The biocompatible implant disappears over time.
Soon pet owners may be able to prevent their male dogs from breeding without castrating them thanks to
Suprelorin, a canine birth control implant developed in Australia. "Some male owners, particularly those with 'macho' breeds of dogs, are not keen to castrate their pets," said Dr. Tim Trigg, managing director for
Peptech Animal Health (Sydney, Australia), which markets
"A quick and easy implant gives them a more humane, cost-effective choice that leaves their dogs intact but is equally efficacious. The same benefits apply to dogs being shown, of course." In addition to preventing reproduction, the implant treats testosterone related
It also is approved to treat benign prostatic hyperplasia, a non cancerous enlargement of the prostate gland common in older dogs that have not been neutered.
Trials show Suprelorin is also effective in controlling populations of
Elephants, Lions, Cheetahs, Monkeys, Dolphins, Seals, Koalas and Kangaroos.
Suprelorin is a non-surgical alternative to castration that delivers male dogs all the contraceptive, health and behavioural benefits of castration. The slow-release product stops the hormones that cause testosterone production. This means that:
fertility is controlled and ejaculation stopped;
painful prostate problems, particularly common in older dogs, can be treated; and
anti-social behaviour such as sexual aggression or wandering is prevented
All these benefits occur without having to resort to surgery, which requires an anaesthetic and a recovery period.
The retail cost: about $60 a dose, compared to between $150 to $300 estimated for castration. The implant is effective for at least six months.
Trials with more than 500 dogs over eight years have shown no side effects.
The implanter is like the one used to implant microchips. As a treatment for prostate problems, Suprelorin is unique in the market because it lasts for six months without the owners having to come back for additional treatment.
Reasons not to castrate
The implant is more humane than surgery; many dog owners, particularly men and or for cultural reasons would prefer to leave their dogs intact; 'show' dogs also need to be intact for shows; and people may want to breed their dog later on (fertility is shown to return after treatment stops) but might be having behavioural issues for the first few years
Suprelorin, manufactured by Peptech Animal Health, is an Australian invention. The company has patented the material in the implant that allows the active ingredient to release slowly over time. The small implant (12mm long and 2.3mm thick) does not have to be removed - it softens and dissolves over time.
Desexing is not reversible and the perfect age is six months.
Use in females for
Use in hormone responsive
Use in other species
(population control) - ongoing
of Current Approaches
ACC&D’s Priorities for Non-Surgical
Products for Pet Population Control:
- Approved by regulatory agencies as
safe (for animals and for the humans administering) and
- Permanent. Though there may be
some opportunity for long term (3+ years) products.
- Deliverable in a single injection
- Product/s available for effective
use in both male and female, dogs and cats.
- Documented effects on behavior and
- Can be provided at affordable
rates for use in indigent or low-income client populations.
Below we’ve included brief
descriptions of some of the more promising approaches. For a more
thorough review of recent research, please see the Proceedings
of the Third International Symposium on Non-Surgical Contraceptive
Methods of Pet Population Control.
Status: Early stage development (dose levels,
formulation) in dogs. Preliminary work in cats.
What it is: An industrial chemical that has been
shown to deplete the ovarian follicles and cause sterility in
rodents. Some preliminary data showing this effect is also seen in
ACC&D Perspective: While this approach is in
the very early stages of development, we believe it shows promise
for meeting our priorities for non-surgical sterilization products.
ACC&D has provided funding for one Senestech study and is in
discussions with Senestech regarding further collaboration.
For More Information: Review
materials from Dr. Loretta Mayer’s presentation on ChemSpay at the
2006 ACC&D Symposium.
From: Peptech Animal Health
Status: Approved and available for use in male dogs
in Australia (6 month and 12 month doses) since December 2004 and
New Zealand (6 month dose only) since September 2005. Received EU
regulatory approval March 2007 and hopes to make the product
available in Europe in the second half of 2007. Peptech has
announced plans to seek approval for future global use.
What it is: A deslorin (GnRH agonist) implant for
male dogs resulting in sterility for six or 12 months (both
ACC&D Perspective: Because Suprelorin is not
permanent, it is not an ideal product for population control.
However, we believe Suprelorin may have potential to fill a niche in
certain cases. We are also interested to see if new formulations
might be developed to provide longer term contraception.
For more information: Visit
Peptech Animal Health’s web site and read ACC&D's
interview with Peptech's Paul Schober.
From: Abbott Laboratories
Status: Neutersol is approved by the FDA for use in
the US. Neutersol is currently unavailable, however the patent
holder announced in November 2006 that they are working with Abbott
Laboratories, which will be manufacturing and distributing the
product in the U.S. in the “near future”. A release date is not
What it is: Neutersol is an intratesticular
injection of zinc gluconate neutralized by arginine. Neutersol is
approved by the FDA for use in male dogs from 3-10 months of age,
though it has been shown to be safe and effective for adult dogs
through off-label use. Neutersol may be approved for use in male
cats in the future.
ACC&D Perspective: Zinc gluconate (brand name:
Neutersol®) is the only non-surgical pet sterilant approved as safe
and effective for use in the US. Zinc gluconate is cheaper and
easier to administer than surgical sterilization is to perform. A
10,000 dog study in Mexico has demonstrated both safety and
effectiveness in adult dogs and in large field programs. ACC&D
believes that zinc gluconate is a promising international tool for
For More Information: Read the proceedings from the
session at ACC&D's Third International Symposium
From: Invervet France
Status: Received regulatory approval in November
2006 in the European Union.
What it is: The active ingredient, azagly-nafarelin,
is a GnRH agonist. A silicone implant provides one-year reversible
contraception for female and male dogs and cats.
ACC&D Perspective: While this does not fit the
profile of a permanent tool for population management programs, Dr.
Driancourt announced some limited data in cats showing that when the
implant is not removed, queens had suppression of estrus over an
extended period of time – nearly three years so far. This raises
the possibility that the product might be useful in the control of
feral cat populations, although the expense involved in
manufacturing GnRH agonists may be a limiting factor.
For More Information: Review
materials from Dr. Marc-Antoine Driancourt’s presentation on
Gonazon at the 2006 ACC&D Symposium.
From: National Wildlife Research Center of the USDA
Status: Data is being submitted to the EPA
initially for approval for use in deer and other cervids. Separate
studies underway assess potential for use in dogs and feral cats.
What it is: A GnRH vaccine developed and tested for
use in several wildlife species, and the basis for a vaccine being
assessed for use in cats.
ACC&D Perspective: GonaCon has been shown (in
preliminary research) to be effective in approximately 75% of female
cats for 2 and ½ years to date.. Because GonaCon is assumed to not
be permanent and is not effective in 100% of animals, it is not
ideal. However, we believe GonaCon may have potential to fill a
niche in feral cat colony management.
For More Information: Review
materials from Dr.
presentations at the 2006 ACC&D Symposium.
Gonadotropin Releasing Factor Immunotherapeutic
From: Pfizer Animal Health
Status: Has received conditional approval from the
FDA. (Available now.)
What it is: A GnRH vaccine developed and marketed
for treatment of benign prostatic hyperplasia (BPH), a common health
problem in post-pubescent, intact male dogs. While not labeled for
use as a contraceptive, a side effect of the treatment is
contraception and a reduction or elimination of testosterone-related
behaviors. Administered via subcutaneous injection. Repeated every
ACC&D Perspective: While this treatment does
not meet our priority of being permanent or long-term, we are
excited to see the first GnRH vaccine approved for use in dogs in
the U.S. We believe there may be some potential niche use for
For More Information: Click here to read the product
profile from Pfizer.