Frequently asked questions about the use of calcium chloride for castration

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What is calcium chloride?

Calcium chloride is a desiccant that necrotizes testicular tissue in male dogs and other animals.  It is safe, convenient, inexpensive, non-toxic to those handling it, and its effects are permanent.

The sterilant fulfills the principal requirements for application to a population of stray canines. A single, bilateral intratesticular injection for stray dogs is effective in achieving long-term infertility, inhibits sexual behavior, does not cause chronic stress to the animal, causes few inflammatory reactions, lacks other undesirable side effects, is easily performed, and is economical.

Is castrating with calcium chloride permanent?

Testicular and epididymis pathology was performed on 14 dogs 3-30 days post injection.

  1. The testis showed inflammatory response with mineralization, fibrosis, and tubular degeneration leading to necrosis.
  2. Epididymides showed similar inflammation, mineralization, and fibroplasia leading to necrosis of the tissue.
  3. These kind of changes to those tissues will render the animal sterile permanently.

What happens after the animal is injected?

Initially the testicles and scrotum will swell, but in about one month the scrotum will be back to normal size and the testicles will have become small hard globules.

Go here to see a pictorial of what happens.

Are there possible complications of this method?

Tissue necrosis will occur if calcium chloride is accidentally leaked into the subcutaneous tissue. The lesion is generally not accompanied by fever, loss of appetite or lethargy. Spraying the lesion with clean water followed by mild salt water (1/2 teaspoon salt to 16 oz. of water) twice daily for seven days will help the healing of the lesion.

A lesion may develop when swelling causes the scrotum to have prolonged contact with the medial thigh. That lesion will resolve in about the same amount of time as the testicular necrosis, but there may be some discomfort. Limiting activity and symptomatic therapy for pain is useful.

Is injecting with calcium chloride painful?

What is unusual and not generally known about the physiology of the testes is that there are no pain sensors inside the testes, only pressure sensors.
In Leoci’s studies no or minimal signs of discomfort were observed following injection, with variations dependent on the agent injected. Minor transient pain occurred during the injection, as any needle inserted through skin will cause somatic pain for an instant. The explanation for the relative lack of discomfort following the injection is that afferent nerve endings associated with pain sensation are located on the scrotal skin and in the capsule of the testis, rather than within the testicular and epididymal parenchyma. Given the anatomy of the testes, severe testicular pain when experienced is visceral and triggered by rapid pressure deforming the testicular capsule. During chemical castration, it is important to deliver the injection very slowly to avoid triggering the testicular pressure receptors.

Does calcium chloride reduce testosterone?

In dogs with testis under 25 mm in width the reduction of testosterone is greater than with larger dogs and may be as low as in dogs that are surgically castrated.  According to research published in 2014 (http://www.actavetscand.com/content/56/1/62) the reduction of testosterone has been shown to be significant.

Is calcium chloride safe for employees or volunteers who may come in contact with it?

Calcium chloride in ethyl alcohol is not caustic and can be safely cleaned off of hands with soap and water.

How affordable is calcium chloride castration?

In a dog requiring an average 1.5 ml calcium chloride per testicle, the cost of calcium chloride, alcohol, needles, syringes and drugs for sedation will cost US$ 1.00.

What are the benefits to using calcium chloride in remote area programs such as in “MASH” programs?

Because the animals are only sedated and do not require anesthesia, recovery time is shortened, therefore programs can be extended into times of year in which surgery would often be avoided.  In programs in which animals are normally transported to and from the clinic site, the male dogs and cats can be neutered in their own communities, saving space on crowded transport vehicles.

The sterilant fulfills the principal requirements for application to a population of stray canines. A single, bilateral intratesticular injection for stray dogs is effective in achieving long-term infertility, inhibits sexual behavior, does not cause chronic stress to the animal, causes few inflammatory reactions, lacks other undesirable side effects, is easily performed, and is economical.