The answer may be found in a study done on a statistically significant number of dogs in Chile.
It concluded the majority of dogs displayed no long-term (up to 6 months) testosterone levels change after chemical sterilization.
Does castration help reduce roaming?
The implications? We need to better understand the role testosterone plays on sexual, aggressive and
roaming behaviours to appropriately chose the best method of sterilization and intended impact on male dogs beyond shooting blanks.
Our team does not believe, at this point, that chemical sterilization is an ideal choice for free-roaming rez dogs: if a chemically castrated dog continues to pursue females in heat and engage in dog aggression, it remains a public safety issue.
Dr. Judith Samson-French
Effects of surgical and chemical sterilization on the behavior of free-roaming male dogs in Puerto Natales, Chile.
Garde E1, Pérez GE2, Vanderstichel R3, Dalla Villa PF4, Serpell JA5.
In my opinion, the answer is no.
But let’s get a little background info first.
Chemical castration of dogs refers to two products: Zeuterin (Zinc gluconate) and Calcium chloride. The former is approved in USA (but not in Canada) while the latter has not had proper clinical trials to evaluate its efficacy and safety. Both involve injecting testicles with a chemical to produce tissue atrophy. Tissue swelling (which occurs from the mere fact of injecting liquid into a capsular structure) is a primary cause of discomfort post-injection and pain management must be implemented.
Zeuterin, unlike surgical castration, leaves enough testosterone behind to produce testosterone driven behaviours such as mounting of females (but shooting blanks), roaming and packing. Those are precisely behaviours that people living in our remote and isolated communities find undesirable.
As for Calcium chloride, there is an overall lack of consistency in formulation, dosage, and administration as well as inadequate measures of sterility, safety, and testosterone reduction. For those reasons, Calcium chloride needs more controlled clinical trials BEFORE its use in the field for purpose of sterilization be considered.
Because both products may produce significant pain and debilitating scrotal problems, chemically sterilized dogs should be kept under supervision and pain management implemented for one to two weeks post injection. This is simply not feasible with free-roaming dogs, dogs with no names.
As always, when trying new medical protocols in the field, one must be very conscious not to take advantage of disadvantaged populations who do not know better.
Dr. Judith Samson-French