brown timberlands First US data shows nonsurgical dog neuter shot also effective in cats
Old habits die hard. If veterinarians could sterilize male cats and dogs with a simple shot for less than a dollar a dose, why choose surgery? Well, now there’s a choice and some veterinarians, shelters, and rescue organizations are daring to try the new way. Northwest veterinarian and shelter have won the first “Timmy Prize” for data collection, submitting data on their experience using CalchlorinTM nonsurgical neuter injection to spare three feral cats surgery. The prize, offered by nonprofit Parsemus Foundation, is meant to encourage sharing and transparency of data on the neuter injection. Because the universally available method is not patentable and there is very little profit potential, no company is sponsoring it or spreading data. “Market approaches can solve a lot, but in this case, we saw a need that wasn’t being filled,” said Elaine Lissner, executive director of the nonprofit foundation.
The prize is named in honor of Timmy, the beloved dog of two donors who sponsored the prize. “We read about Calchlorin in the Wall Street Journal last fall. It seemed crazy that this simple solution, which could spare dogs and cats surgery, wasn’t being taken through the FDA by the big organizations.
“When we adopted Timmy, nobody knew about Calchlorin so of course we had him neutered the usual way,” continued Timmy’s owners. “But worldwide, not everybody can afford surgery. And given an option, I’m sure Timmy would have preferred a shot.”Dog overpopulation is a problem globally, despite a range of efforts to control population growth. The American Society for the Prevention of Cruelty to Animals estimated that 3.9 million dogs enter shelters in the United States only a fraction of the total number of homeless animals. In many developing countries, free roaming dogs cause serious health and welfare problems that create socio economic, ecological, political, and ethical dilemmas. Mass sterilization programs are often prohibitively expensive, especially in resource restricted areas. An alternative method to surgical sterilization that is effective, easy to administer, safe, and affordable would offer immense benefits, allowing animal welfare organizations, public health programs, and governments to reach further with limited resources.
Calchlorin sterilization, a potent solution
Calchlorin neuter shot, comprised of 20% calcium chloride dihydrate in ethyl alcohol, could be the answer at least to half the problem. It eliminates the expense, surgical risk, and logistical challenges of doing surgery, at least on the males allowing shelters and rescue organizations to concentrate scarce resources on sterilizing females. Although spaying female dogs makes the most difference for reducing population, male dogs must be sterilized too in the case of street dogs, to reduce dangerous packing and fighting behavior, and in the case of pets, to reduce nuisance behaviors such as marking and mounting that end them back up in the shelter.
Neglected for decades
The use of chemical injections to castrate animals has been studied for over fifty years. While many chemicals are known to eliminate sperm when injected into the testicles, side effects were common. Koger and his team at Washington State University, Pullman. But the procedure was neglected for decades until Indian researchers Drs. Samanta began exploring its use in companion animals. Their research provided good indications that calcium chloride could indeed be an ideal chemical sterilizing agent. Their short term studies in dogs and cats have been published over the past decade. However, this evidence did not result in broad adoption of the procedure, despite the potential positive impacts that a nonsurgical sterilization method could have on animal and human welfare.
Published studies from Italy
The results from two new studies have built on the research from India and clarified the optimal formulation for nonsurgical sterilization of male dogs. The scientific manuscripts,
published last fall as open access articles in Acta Scandinavica Veterinaria, report that a 20% solution of calcium chloride dihydrate in alcohol (“Calchlorin”) provides the optimal solution for safe and effective nonsurgical sterilization. A simple and quick intratesticular injection of Calchlorin caused infertility for 12 months and a reduction in testosterone with accompanying loss of male dog sexual behavior.
The research program, led by Dr. Raffaella Leoci of University Bari Aldo Moro in Italy, was the first to evaluate the long term effects of the procedure on hormones, health and sperm characteristics in a large number of dogs. Dr. Leoci specializes in animal reproduction and is passionate about finding better sterilization options.
“Italian law has a no kill policy, and stray dogs are captured, microchipped, neutered and taken to dog shelters or just released when the shelters are too full. The trap/neuter programs are not on a large enough scale and the dog population is growing fast. This has led to serious health and welfare concerns,” said Dr. Leoci. “Surgical castration is not a practicable solution it is too expensive and time consuming. My priority was to find an alternative method to prevent dog reproduction that is safe, effective, low cost and easy to perform to prevent the suffering dogs experience as strays.”
The initial study evaluated a number of concentrations of the chemical, and the second study evaluated the best diluent (solvent) to find a combination that is the most effective with fewest side effects. A 20% CaCl2 solution in alcohol (being called “CalchlorinTM”) proved to be safe and effective over the 12 month trials. The procedure has the potential to revolutionize large scale dog sterilization programs, since it enhances welfare and reduces costs dramatically as compared to traditional surgical castration.”For a long time, people, including vets, assumed that a testicular injection would be inhumane which is logical, since we all know getting bashed in the testes is excruciatingly painful,” said Elaine Lissner, executive director of the nonprofit Parsemus Foundation, which sponsored the research. Lissner first read about calcium chloride in 2007 and, intrigued, requested a demonstration when she was in India in 2009. What she saw surprised her.
“I was amazed when I saw calcium chloride demonstrated in India that, though the dogs or cats sometimes yelped a little when the needle went through the skin just like for any other shot, they settled down once it was in. It’s not what you’d expect at all.”
Curious, Lissner asked expert veterinarian colleagues to explain. “It turns out that although there are nerves in the capsule of the testes that are exquisitely sensitive to pressure, there are not many pain nerves actually inside the testicular tissue. So as long as the injection is slow enough to not create pressure, it’s amazingly well tolerated.”
As a proponent of nonsurgical neuter methods and a scientific advisory board member of the Alliance for Contraception in Cats Dogs, Lissner heard that practitioners wanted to see more data on the safety and long term efficacy of using calcium chloride. Lissner allocated funds for the research led by Dr. Leoci to evaluate these concerns.
“Of course a nonsurgical sterilant for females is the holy grail from a population standpoint and there’s big money going towards that effort. But that’s trickier. Now if rescue groups can at least get the males done quickly and easily so they can focus their resources on females, they have the first game changing tool ever.”
Behavior change is key
Preserving testosterone can be important for health reasons, particularly in large and giant breed dogs. The FDA approved sterilant ZeuterinTM is marketed as being more hormone preserving and creating “no significant change in behavior.” But for a sterilant to replace the great majority of castration surgeries in shelters and clinics, a reduction in testosterone related dominance and sexual behavior is needed. “Pack behavior,” including fighting over females in heat, is a prominent problem created by free roaming dogs and creates conflict with the human and animal populations nearby. And a pet dog that is mounting everything, breaking out regularly, or marking indoors is likely to end up back in the shelter and possibly euthanized. Surgical castration greatly reduces these behaviors by removing the production of testosterone from the testes, making dogs more likely to keep their homes.
Dr. Leoci explains “As a rule, castration is most likely to be curative when the problem behavior is influenced by testosterone, such as scent marking, roaming away from home to find potential mates, inappropriate sexual behavior, aggression towards other males, and sometimes competitive aggression towards humans. It does not necessarily affect other behavior problems. In our study using the optimal solution of calcium chloride in alcohol, we did notice a reduction in testosterone linked sexual and aggressive behavior.”
Spraying, roaming, yowling: Changing behavior is key in cats, too
The winning veterinarian and shelter made use of a little known fact: cats have penile “spines” that are testosterone dependent. By photographing the spines shrinking after Calchlorin injection,
they were able to document testosterone reduction even without a blood draw.