An affordable and effective non-surgical technique for achieving male
dog sterility is needed to solve the problem of overpopulation. The
efficacy of 20% calcium chloride in pure alcohol solution, injected into
the testicular parenchyma, as a method for chemical castration, was
evaluated. Twenty-one dogs of mixed breed, 4.7 ± 1.23 years old,
20 ± 5.84 kg of body weight, with good clinical conditions and
normal reproductive parameters, were lightly sedated and injected into
the dorsocranial portion of both testes with a solution of 20% calcium
chloride dihyrdate in ethanol (95%). The dose injected corresponds
with the testicular width (19–22 mm receive 0.8 ml; 23 and above
1 ml). Semen evaluation was performed by CASA (Computer Assisted
Sperm Analysis) system at day 30–60–90. The animals in the control
group received a single bilateral intratesticular injection of 1 ml sterile
saline solution (testicular width 23 mm and above). Forty-eight hours
after the injection, dogs showed very light discomfort at palpation and
testicular tumefaction, which regressed within 3 days. At day 30,
testicular ultrasonography revealed bilateral more dense nodular
lesions; prostatic volume and parenchyma were normal. Semen
evaluation showed azoospermia at day 30–60 and 90. The sperm
count was decreased significantly (p < 01) in all the CaCl2 treated
dogs in comparison to saline solution control animals. At day 90
testicles were shrunk at palpation. An intratesticular injection of 20%
calcium chloride in pure alcohol solution, as a method for chemical
castration, was effective and economical for the sterilization of male
dogs. It is free from pain and chronic stress and will contribute to a
simple alternative method to surgical castration. The dogs of this study
are under evaluation to study this solution long term effect (1 year)
