Non-Surgical Contraceptive Techniques in Male Animals

Non-surgical approaches to male animal contraception have advanced significantly in recent years, driven by the need to control companion and free-roaming populations without the cost, logistics and welfare concerns of surgical castration. Chemical sterilants delivered via intratesticular injection—such as calcium chloride, zinc gluconate or hypertonic saline—induce local tissue necrosis or fibrosis, leading to long-term azoospermia and reduced androgenesis. Physical modalities including therapeutic ultrasound and magnetic nanoparticle hyperthermia target spermatogenic cells by applying controlled heat or mechanical disruption. Immunocastration strategies harness the animal’s immune system to block hormones or gamete-specific proteins, offering potentially reversible suppression of sperm production. Gene-editing techniques aim to disrupt testis-specific genes, providing precise and durable sterility. Together, these methods span a continuum from reversible to irreversible effects, and their refinement holds promise for global population management in dogs, cats, livestock and wildlife with improved animal welfare and broader accessibility.

Research from Nature Portfolio

A foundational study demonstrated the use of a nanostructured lipid carrier to deliver α-mangostin directly into the testis. This formulation achieved targeted uptake by spermatogonia, induced widespread germ cell apoptosis and disrupted seminiferous tubule architecture without systemic toxicity. Particle size and surface charge optimisation ensured stability and localised action, marking a significant step towards injectable, non-surgical fertility control that spares androgen-producing Leydig cells and preserves hormonal function.

Non-Surgical Contraceptive Techniques in Male Animals publication trend

The graph below shows the total number of articles in non-surgical contraceptive techniques in male animals across all publications each year (not limited to Nature Index journals).

Technical terms

Intratesticular injection: Administration of a contraceptive agent directly into the testicular parenchyma.

Azoospermia: Complete absence of spermatozoa in an ejaculate, indicating sterility.

Nanostructured lipid carrier: Nanoscale lipid-based vesicle designed for targeted delivery of bioactive compounds.

Magnetic nanoparticle hyperthermia: Technique using magnetic nanoparticles and an alternating magnetic field to generate localised heat for tissue ablation.

Immunocastration: Vaccination strategy that induces an immune response against reproductive hormones or sperm antigens to suppress fertility.

References

1. Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system. Reproductive Biology and Endocrinology (2012).
2. Nanocarrier-mediated delivery of α-mangostin for non-surgical castration of male animals. Scientific Reports (2017).
3. Male animal sterilization: history, current practices, and potential methods for replacing castration. Frontiers in Veterinary Science (2024).
4. Effects of intratesticular injection of hypertonic mannitol and saline on the quality of donkey sperm, indicators of oxidative stress and testicular tissue pathology. BMC Veterinary Research (2024).
5. New Prospects in Neutering Male Animals Using Magnetic Nanoparticle Hyperthermia. Pharmaceutics (2021).