SAN FRANCISCO––An injectable calcium chloride chemosterilant costing only pennies per dose has been tested successfully in male cats, following years of positive results in dogs, the San Francisco-based Parsemus Foundation on April 29, 2015 announced via the American Association for the Advancement of Science’s “Eureka Alerts” media release distribution system.
The Parsemus Foundation honored an unidentified “U.S. Northwest veterinarian” at an unnamed animal shelter for submitting particulars of trials of the chemosterilant, called Calchlorin, in three feral cats. Calchlorin consists of a 20% calcium chloride dihydrate mixed with ethyl alcohol.
Anonymous vet & shelter
The Parsemus Foundation honored the anonymous veterinarian and shelter “to encourage sharing and transparency of data on the neuter injection,” the media release said, but offered little more about the trial in male feral cats, while mentioning that the award given to the vet and shelter “is named in honor of Timmy, the beloved dog of two donors who sponsored the prize,” who was conventionally neutered.
“All the vets are so nervous about being one of the first––doing anything innovative puts them at risk of being accused of not following ‘standard of practice’––that we figured we would collect the data now, and people can start being open about who they are when use is more prevalent,” Parsemus Foundation executive director Elaine Lissner told ANIMALS 24-7.
“Research on calcium chloride goes back to the 1970s,” summarized Wall Street Journal staff writer Melinda Beck in November 2014, “when it was tested as a sterilizing agent in calves, colts and other animals. In the past decade, researchers in India published a dozen studies using it in dogs, cats and goats.”
However, Beck continued, “Calcium chloride isn’t approved by the U.S. Food & Drug Administration and probably will never be. It’s such a common chemical that it can’t be patented. As a result, drug companies aren’t interested in investing the $10 million or more needed to run the required clinical trials. Without FDA approval, most veterinary and animal-welfare groups are leery of endorsing it.”
FDA refused to waive fee
Lissner “tried to start the FDA approval process for the use of calcium chloride in male cats last year,” Beck wrote, “but her bid for a ‘barrier to innovation’ waiver of the $87,000 application fee was denied on the grounds that the research wasn’t ‘innovative’ enough.”
Despite that setback, and despite discouragement from promoters and developers of more costly chemosterilants, as well as veterinarians who prefer to do surgical castration or vasectomies, “The winning shelter is not the first in the U.S. to try the neuter shot,” the Parsemus Foundation acknowledged. “Spay FIRST!,” which provides sterilization services on several Native American reservations in Oklahoma, “tried calcium chloride nonsurgical neutering with great caution after hearing the results [of overseas trials] presented at the First International Conference on Dog Population Management in York, England,” in September 2012.
When a trial of Calchlorin in three dogs was successful, Spay FIRST! founder Ruth Steinberger expanded her use of it.
“Easier on dogs than surgery”
“It’s so much easier on the dogs than surgery,” said Steinberger. “We are able to use it in cold weather for many more dogs because there is little recovery time. A technician can inject under the supervision of a veterinarian so it saves professional time, shortening remote area clinics. And best of all, it works.”
Described Beck, “The dogs get a light sedative, but there is no need for general anesthesia or incisions. They can be up and running again in minutes. The cost: about $1 per dog. “Calcium chloride could be a boon to animal shelters in other impoverished areas, many of which lack the funds and the facilities to sterilize dogs surgically,” Beck assessed. “But few veterinarians and shelter operators even know about calcium chloride. It’s been stalled in a regulatory Catch-22 that illustrates how products that don’t have much profit potential can languish unused.”
After Beck’s article appeared, the Parsemus Foundation “Eureka Alert” recounted, Spay FIRST! “received inquiries from all over the world, places where surgery is prohibitively expensive or impractical from a logistical standpoint,” and is “currently partnering with a Caribbean organization which wishes to introduce [use of Calchlorin] to neuter strays.”
Added the Parsemus Foundation release, “The qualities of calcium chloride as a safer chemical sterilant have been known since 1977 and 1978 publications by L.M. Koger and his team at Washington State University, Pullman. But the procedure was neglected for decades until Indian [veterinary] researchers Kuladip Jana and P.K. 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.”
Becoming interested in the potential of calcium chloride as a chemosterilant in 2007, the Parsemus Foundation has funded studies by animal reproduction specialist Raffaella Leoci of University Bari Aldo Moro in Italy, who “was the first to evaluate the long-term effects of the procedure on hormones, health and sperm characteristics in a large number of dogs,” the “Eureka Alert” said.
Leoci’s work suggests that Calchlorin may have a significant advantage over other currently available chemosterilants, apart from cost, because unlike any of the other injectable products it reduces testosterone production by the injected animal.
“As a rule,” said Leoci through the Parsemus Foundation media release, “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 toward other males, and sometimes competitive aggression towards humans. It does not necessarily affect other behavior problems.”
Observed the Parsemus Foundation, “Reducing testosterone is especially critical when sterilizing cats. Unneutered male cats have extremely potent-smelling urine and are not adoptable as house pets. Yet surgically neutering large numbers of cats, especially transporting feral cats from the field, presents logistical problems. This makes the first U.S. data on cats particularly notable.”
Kathmandu Valley study
A second funder of calcium chloride chemosterilant research, the Greenbaum Foundation, at the First International Conference on Dog Population Management in September 2012 reported a successful trial in dogs by an organization called DREAMS in the Kathmandu Valley of Nepal. DREAMS veterinarians Arjun Aryal and Awadesh Jha, with technician Kailash Thapa, injected the testicles of 766 male dogs with a solution of calcium chloride dihydrate and the anesthetic Lidocaine as part of their spring 2012 anti-rabies vaccination and sterilization drive. The field trial included 324 street dogs, 301 pets, and 141 community dogs, who were fed regularly but are not associated with any one household. The DREAMS team vaccinated but did not sterilize 531 female dogs from the same neighborhoods.
Follow-up was done only for the community and owned dogs, Aryal and Jha reported, as re-capturing the street dogs for examination proved to be impractical. Visits were done one, three and seven weeks after the calcium chloride sterilizations.
No side effects were noticed except restlessness for few days, Aryal and Jha said. Some of the dogs had swollen testicles. No other pronounced complaints were found.
Unfortunately, ANIMALS 24-7 learned from a visit to Aryal in January 2014, the 2012 trial was not followed up, and Aryal was unaware that the results from it had been published. The April 25, 2015 earthquake that hit the Kathmandu Valley may have prevented any further calcium chloride research in Nepal within the foreseeable future.