Castration by implant of the male dog: advantages and disadvantages


In France, about 30% of male dogs are neutered. For about ten years, the castration of the dog by implant is an interesting alternative to surgical castration. Safe and effective, it does not require general anesthesia. It also has the advantage of being reversible.

Are you hesitating to have your companion sterilized? The removal of the testicles is indeed a definitive act which can frighten the masters. And if you opt for sterilization by implant of the dog? This technique can be occasional, for example to “test” the effect of castration on your animal, or repeated for permanent contraception. But, by the way, how does an implant work in dogs?

What is dog sterilization by implant?

For about 13 years, veterinarians have had implants to sterilize male dogs.

  • What is an implant?

An implant is a small cylinder (1 to 2.5 cm long) composed of biologically compatible lipids that is implanted under the skin. It will then release a drug continuously for several weeks. In the case of dog implants, it is deslorelin.

Contraceptive implants are also used in human medicine, in women.

  • How does the implant work on the dog?

Deslorelin has an action on the production of testosterone which strongly decreases resulting in sterility of the dog (stopping of sperm production).

Due to this decrease in testosterone, the size of the testicles decreases and certain sex-related behaviors disappear (urinary marking, overlapping, etc.).

The average duration of action of the implant is 6 to 12 months, or even longer depending on the dosage and the dog. In small dogs of the Chihuahua or Spitz type, the action of the implant is often longer. At the end of this period of time, the animal can be reimplanted, castrated surgically or return to its life before!

  • How is the placement of an implant in dogs carried out?

The implant is injected under the skin, between the shoulder blades, using a special syringe equipped with a needle of enough gauge to allow the passage of the cylinder. To be implanted, the dog must be pubescent (between 6 and 15 months of age depending on the breed).

  • What are the side effects of implant castration in dogs?

Swelling at the injection site can sometimes be noted in the days following implantation of the device. A small boost in libido can also be observed, but exceptionally!

Hair loss or coat change related to low testosterone is possible, but rare. As with surgical sterilization, weight gain remains the most common side effect. This risk is managed with the help of an appropriate plan.

Castration by implant versus surgical castration of the dog?

Castration, whether surgical or chemical, may be indicated for several reasons:

  • Avoid unwanted pregnancies when male and female live together
  • Remedy certain behavioral problems of male dogs such as urine marking, overlapping, intra-specific aggression, running away, excitement due to female dogs in heat in the neighborhood
  • Medical: tumor of the testicle or circumanal glands, prostate hyperplasia…

Surgical castration consists of the removal of the testicles. It requires anesthesia and is, by nature, irreversible. This so-called convenience operation is very well mastered by veterinarians and accidents are extremely rare.

The implant has the advantage of simplicity of placement (a simple injection without anesthesia) and reversibility. Note that the trocar for this injection is still of a good caliber and this act can be briefly painful, especially in small dogs. After 6 months, the injection can be renewed, then every year.

Placing a contraceptive implant for dogs can also be a way to realize the effects of castration in your animal before opting for permanent surgery. The predictivity of this test is excellent. For example, if you want to castrate your dog for running away, you can opt for an implant first. If he continues to run away, no need to castrate him, it won’t change anything! Similarly, if your Labrador gains a lot of weight with his implant, it will probably be the same after castration, which can be problematic for his joints. In this case, it will be better to give up castration, or, if this is not possible, to set up a draconian diet.

castration of the dog Implant Surgery
Anesthesia Nope Yes
Pain At the time of injection On waking and a few days after surgery, but controlled by painkillers
Reversibility Yes (with exceptions, especially in small breeds) Nope
Weight gain Possible, but reversible Possible (frequent)
Cost 115 to 200 euros (excluding consultation) 130 to 300 euros depending on the weight

When will the female dog be sterilized by implant?

And the female in all this? Currently, implants are restricted to pubertal male dogs. A few studies have been done in adult female dogs, but have been inconclusive. Indeed, the placement of the implant induced heat in the days following the placement in 100% of the female dogs. In addition, bothersome side effects, such as ovarian cysts, onset of lactation or uterine infection, have been reported. An attractive alternative to ovariectomy, sterilization by implant of the female dog is not yet on the agenda.

Dr Isabelle Vixege



Please enter your comment!
Please enter your name here