Identification of Dogs Receiving Hormone Sparing Sterilization

Jack Russel dog for Identification of Dogs Receiving Hormone Sparing Sterilization

Project Summary: Identification of Dogs

Increasing numbers of dogs have received hormone-sparing sterilization — hysterectomy (also called ovary-sparing spay) for females and vasectomy for males — to avoid the negative impacts from hormone loss. But hormone sparing methods may not be obvious. To ensure that lost or rehomed dogs do not receive a repeat surgery, it is important to use standard identification of dogs that had a hysterectomy or vasectomy.

Use our Veterinarian Directory to find a veterinarian near you who offers hormone-sparing sterilization.

NEW: Infographic on the risks of spay and neuter, which you can use to raise awareness.

Project Topics

Promoting choice for optimal animal health

Hormone-sparing sterilization methods ensure population control while guarding the lifetime well-being of dogs. Hysterectomy (also called ovary-sparing spay) for females and vasectomy for males are ways to sterilize pets without the negative impacts from hormone loss. For a recent overview on the health implications of traditional spay and neuter, and a review of hormone-preserving contraceptive options, see this article in the Innovative Veterinary Care journal. Pet owners can find veterinarians in your area offering ovary-sparing spay as an option. Veterinarians can review information on canine hysterectomy and vasectomy and register their veterinary clinic in the free directory to connect with clients. Also, visit the Facebook Ovary Sparing Spay and Vasectomy Group for a list of veterinarians who offer alternatives to traditional spay and neuter and to share your experiences.

Identification of dogs with hormone-sparing sterilization

Knowing whether a dog was sterilized is critical for preventing unnecessary repeat surgeries. However, lack of standardization has been a barrier. After a review of common identification methods for owned dogs and methods being used currently by veterinarians, a simple tattoo in the inguinal area is recommended as the standard for hormone-preserving sterilization methods:

  • Hysterectomy: Green “X” slightly lateral to midline near umbilicus
  • Vasectomy: Green “V” lateral and cranial to scrotal region

The simplicity of the marks does not require dedicated tattoo equipment or special skill, so that most veterinarians could provide the identification. Tattoos can be created using a needle or scalpel to apply the tattoo ink to the dermis. The procedure is completed while the dog is sedated for a sterilization procedure  and no additional equipment is needed for detection. Although clarity of a tattoo may decrease over time, in this case it is not necessary that it is legible — just that it’s visible.

Take Action: Identification of Dogs

For Veterinarians

  • Veterinarians who wish to be listed in the directory may do so by filling out the info on the clinic registration form.
  • Use this flyer as an informational piece for your website or as a handout for clients.
  • Email us at if you would like to consult with a veterinarian who is experienced with hormone-sparing sterilization.
  • Review the Additional Resources below. Take note of the information about gonadectomy risks for specific breeds and mixed-breed dogs published by Hart and colleagues (2020) and stay abreast of recent updates in this rapidly evolving area of research.

For Pet Owners

  • Review this flyer to understand whether hormone-sparing sterilization is right for you and your dog. Keep in mind that impacts vary on breed, size and other factors. Check the recent publications about cancer and joint disorders by dog breed and mixed-breed size.
  • Consult with a veterinarian who is familiar with the health issues related to spay/neuter and familiar with hormone-sparing options. Each dog and family is different, and having an expert consultation on the best method of sterilizing your dog is important. 
  • To find a provider you can search the Veterinary Directory or check the information at the Ovary Sparing Spay and Vasectomy Info Facebook Group. If you cannot find a provider nearby, you could pass along the information on this website to your own veterinarian and ask if he or she can provide the procedure. Direct him or her to the information on this website and email us at if additional assistance/advice is required.
  • Please let us know if you find a veterinarian who offers OSS or vasectomy and would like to join our directory!
  • If you choose to preserve your dog’s hormones, consider joining this Facebook group: Training and behavioral advice for Intact Dogs.

Summary documents

  • Download our flyer for a brief overview of hormone-sparing sterilization.
  • Download our infographic on the risks of spay-neuter.

Brent L (2019). Growing interest in hormone sparing dog sterilization and recommendations for standard identification methods. Clin Therio 11(3):247-253. (full text)

What People Are Saying

Veterinarians Offering Alternative Methods of Contraception

For Pet Owners

Looking for a veterinarian willing to perform procedures beyond surgical spay or neuter? Browse our directory of qualified veterinary professionals.

For Veterinarians

Do you offer alternative methods of contraception like ovary-sparing spay and vasectomy? Join our referral directory so new clients can find you.

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