Why Does My Pet Have a Spay-Neuter Tattoo?

Have you spotted a little green or blue line on a pet’s belly? When pets are spayed or neutered, some vets leave a tiny tattoo near the incision. It’s a quick, painless way to indicate that the procedure’s been done.  We’ll walk you through the purpose behind the spay-neuter tattoo and why it matters.

Why do vets tattoo pets when spaying or neutering them?

The reason that vets tattoo pets during a spay-neuter surgery is pretty simple: The tattoo, sometimes called a scoring tattoo, acts as confirmation of the spay/neuter procedure. Surgery and anesthesia always come with some risk of complications and post-surgery pain. So, providing a permanent indicator of a pet’s spay/neuter reduces the chance of an unnecessary procedure.

The spay tattoo also tells other vets, shelters, and anyone who is newly caring for the pet that they’re spayed or neutered. This is especially useful for female dogs and cats, where quickly checking their spay status is otherwise difficult.

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Do vets always tattoo spayed dogs and cats?

No, vets don’t always tattoo spayed dogs and cats. However, a survey from the University of Florida’s Shelter Medicine Program found that tattooing during spay-neuter surgery is pretty common: Specifically, 38 percent of private vet clinics, 98 percent of animal shelters, and 99 percent of dedicated spay-neuter clinics do tattoo the animals they alter.

How spay-neuter tattoos are applied

To ensure the animal doesn’t experience any pain or fear, the vet applies the spay or neuter tattoo during the surgery, when the pet is still under anesthesia. It typically takes less than a minute to complete the tattoo. Most vets choose to make a shallow and narrow incision with a scalpel, fill the cut with nontoxic and sterile tattoo ink, then apply surgical glue over the wound. 

Some vets may also use a traditional tattoo gun, but the scalpel method is more common. This quick and painless procedure ensures permanent confirmation of the spay or neuter. 

What does a spay tattoo look like?

The most common spay tattoo style is a small, narrow green or blue line of about one-half an inch in length. Some vets may also use a series of three dots or even make a tiny “S” to indicate the spay. You may likewise find pets tattooed with a V-shaped marking, though this is much less common. The ink color is almost always green or blue, because this stands out from the pet’s fur and skin pigment. 

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Where is a spay tattoo typically located on a pet?

For dogs and cats, a spay tattoo is typically located on the pet’s abdomen, often right next to the incision site. 

According to visual reports gathered by the University of Florida’s Shelter Medicine Program, 89 percent of tattooed female cats had a tattoo next to their incision site, and 10 percent displayed the tattoo in the incision. For tattooed female dogs, 86 percent had the tattoo line next to the incision site, and eight percent had the tattoo line in the incision. 

Less commonly, vets may place a spay/neuter-indicator tattoo in the left ear flap. The marking can resemble a line, circle, or small series of dots.

Do neutered pets also get tattoos?

Yes, neutered pets may also get tattoos. Although it might seem obvious whether a pet is a male or a female, that’s not always the case. Here are a few reasons why neutered pets are also tattooed.

It’s tough to tell if a cat is neutered

Neutered male cats and spayed female cats can be a bit tricky to distinguish, especially if they are longhaired. This is because without the testes present, the genitals of male and female cats are not nearly as visually distinct as they are with dogs. 

That being said, a neuter tattoo may not be easily visible in long-haired cats either, so carefully inspecting (or even shaving) the area may be necessary to determine if a tattoo is present. Remember to check the inside of the ears as well for the presence of a spay/neuter tattoo.

Cryptorchidism and neuter status in dogs

Some neutered male dogs also have tattoos. This can be especially useful in cases of cryptorchidism — a condition where one or both testicles never descended. Even after surgery to remove the retained testicle(s), the dog’s scrotum may look the same as it did before, which can make it tricky to tell if they’ve actually been neutered. A small tattoo provides a clear signal that the procedure was done and helps avoid any confusion later on.

Alternative spay or neuter identification methods

So, what if the animal doesn’t have a spay/neuter tattoo? There are a few other ways that indicate the pet has been spayed or neutered.

Scars

Look for the presence of surgical scars: For spayed dogs and cats, there will likely be a vertical incision line in the center of their abdomen, near the midline. Depending on when the procedure was done, the scar could be quite faded and difficult to see. For neutered dogs, the surgical scar should be directly in front of (or on) the scrotum. 

Tipped ears

Most commonly seen in feral or stray cats, tipped ears can indicate that they have been spayed or neutered. For this procedure, the vet will clip the very end of the cat’s ear, often on the left side. This is a common practice, especially for unadoptable feral cats who are released back into their feline community after being spayed or neutered. This process is known as trap, neuter, and release (TNR), and these feral cats are typically vaccinated, dewormed, and altered before being released.

Related article

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Microchip

You may also be able to tell if a pet has been spayed or neutered by scanning their microchip. Some companies include spay/neuter status among the information provided. You can have an animal scanned for a microchip at a vet’s office or animal shelter. 

Medical records

If your pet has medical records available from their previous caretaker or rescue facility, you can request that this be sent to you. You may find confirmation, through medical records, of a spay or neuter procedure. 

Ultrasound

Your vet may also choose to perform an ultrasound to determine if your pet still has a uterus (and ovaries) or testes in the case of cryptorchidism. 

Commonly asked questions

Do female dogs get a tattoo when spayed?

Yes, sometimes female dogs get a tattoo when spayed, especially if they were spayed at an animal shelter or clinic. 

Does the spay tattoo go away?

No, a spay tattoo does not go away. They are permanent. It is a permanent indicator of their spay status, although the tattoo’s vividness may fade a bit over time.

What is the green tattoo after spaying?

The green tattoo after spaying confirms that the animal has been spayed. Sometimes, this tattoo may be blue.

Is a spay tattoo mandatory when a pet is spayed?

No, a spay tattoo is not mandatory when a pet is spayed. But animal shelters and clinics often have a policy of tattooing spayed pets during the procedure. 

Why is there a green tattoo on my neutered male?

A green (or blue) tattoo on a neutered male dog or cat indicates that they have undergone a neuter procedure. 

How can I identify a spay tattoo?

To identify a spay tattoo, look for a green or blue line — or other small marking — either next to or on the incision site. You should also look for the presence of a spay tattoo in the inner flap of the pet’s ears. 

What should I do if my pet doesn’t have a spay tattoo?

If your pet doesn’t have a spay tattoo, this might indicate that they aren’t spayed. (However, they may be spayed and may not have received a tattoo.) Other indicators to look for, to confirm they are spayed, include a clipped ear, medical records confirming the procedure, a negative anti-müllerian hormone test, the absence of a heat cycle, a surgical scar near (or on the midline of) their abdomen, a negative ultrasound test, or confirmation of their spay procedure on their microchip records. 

References

AHDC offers test that identifies reproductive status. (2001, August 22). Cornell University College of Veterinary Medicine. www.vet.cornell.edu/about-us/news/20130710/ahdc-offers-test-identifies-reproductive-status.

Spay/neuter tattoos can prevent unnecessary surgery for cats and dogs, Shelter Medicine Program, College of Veterinary Medicine, University of Florida. (2019, October 15). sheltermedicine.vetmed.ufl.edu/2019/10/15/tattoo-study.