Clients often ask me when they should spay or neuter their Mi-Ki. After all, they want to be a responsible puppy owner/guardian. In the U.S., traditionally, it’s recommended that dogs be spayed or neutered around 6 months of age, but that recommendation is beginning to change based on studies of the long-term health consequences of early neutering.

Some breeders are quite fussy about requiring a spay or neuter within a certain window of time. Some won’t even provide registration paperwork without proof of neutering. We understand that there have been people breeding irresponsibly and without authorization. We never want people to breed Mi-Kis casually without doing the proper health tests and inbreeding coefficients. We strive to promote a strong and healthy Mi-Ki breed for generations to come!

We’re hopeful that our screening process has eliminated unscrupulous buyers and would-be breeders with less-than-honorable intentions. We believe you want what is best for your Mi-Ki. After all, your Mi-Ki was an investment and you’ll want them to live a long and healthy life as a treasured family member.

This means taking another look at long-held beliefs about neutering (including spaying) because removing the gonads will forever alter their hormonal chemistry and can have significant implications for a dog’s health.

Our first advice would be not to go to social media to poll other Mi-Ki owners about the proper time for neutering your pet. You will get a million different answers and realize belatedly what a passionate group of people that dog owners are!

Science-based data

Fortunately, there have been some recent studies done on the spay/neuter conundrum so that dog owners can have meaningful conversations with their vets to determine the best course of action for their pet.

I recently attended a webinar on the topic given by the authors of a long-term-study at UC Davis. Their team combed the records of thousands of dogs from the last 15 years, sorting them by breed and gender. Then they categorized these patients as to whether they were intact (never neutered) or by the age when they were spayed or neutered: Early – 0-6 months, 6-12 months, 12+ months, and 2-8 years.

They were looking for how this spay/neuter data corresponds with hip/joint disorders, metastatic cancers, urinary incontinence, and pyometra (uterine infections.) Sadly, no data was recorded regarding endocrine disorders such as hypothyroidism, etc. Other studies have suggested that neutering dogs has an impact on the endocrine system including metabolic function, thyroid function, etc.

Small Breed Findings

According to the UC Davis 2020 study, the big takeaways for Mi-Ki owners is that small breeds were not statistically impacted by neutering, including spays, at any age in regards to hip and joint disorders like so many of the larger breeds.

In small-dog breeds, the occurrence of cancers was low in both those kept intact and neutered. Two exceptions were the Boston Terrier and Shih Tzu where there was a significant increase in cancers with spaying and neutering.

There is a high percentage of Shih Tzu in the Mi-Ki breed profile

One of the tools we use in our kennel to better understand our breed is the Embark DNA breeder’s program. Embark results tell us the traits that our Mi-Kis have (such as coat type, hair color and patterns, and even muzzle length and size estimates.) They also test for hundreds of genetic diseases.

Recently, Embark has also given us access to their data on what breeds are in the ancestors of the Mi-Ki. Remember that all pure-bred dogs came from other breeds at one point!

Here are some screen shots of a few of our Mi-Kis in our program and their breed makeup:

This breed breakdown may be surprising to some of you who have heard that the Mi-Ki is made up of other breeds (especially the Japanese Chin) but the DNA doesn’t seem to bear this out much according to Embark and to the Mars Wisdom Panel.

The health director of the American Mi-Ki Club, Geri Wojeck, is of the opinion that the Bichon Frise that Embark identifies in the Mi-Ki background is probably actually the Coton de Tulear – a close cousin of the Bichon. But I digress… The point is that Shih Tzu genetics are notable in the Mi-Ki!

Shih Tzu spay/neuter recommendations, according to UC Davis

This is the quote regarding the Shih Tzu breed from the 2020 UC Davis Study. The brackets and bold emphasis points are mine.

“The study population was 104 intact males, 112 neutered males, 77 intact females, and 139 spayed females for a total sample of 432 cases. In this small-dog breed there were no occurrences of joint disorders in either intact or neutered males and females, revealing virtually no vulnerability in this regard. There was no occurrence of the cancers followed in intact males and females. In neutered males there was no occurrence of cancers. However, in females, the occurrence of cancers for those spayed at 6-11 mo. was 7 percent and at 1 year this measure reached a significant 18 percent (p <0.01). MC [metastatic cancers] occurred in 3 percent of intact females. PYO [pyometra] occurred in 5 percent of intact females. UI [urinary incontinence] was not reported in any females. Lacking a noticeable occurrence of increased joint disorders or cancers in neutered males, those wishing to neuter should decide on the appropriate age. The picture is very different for spaying females where the increased risk of cancers started with spaying at 6-11 mo., reaching 18 percent with spaying at year 1. The suggested guideline for females is to delay spaying until the female is 2 years of age. Another possibility is to spay a female a month or two before 6 months to avoid the increased risk of cancers.”

So for small-breed males, including Mi-Kis, it really is your choice with your vet for when the time is right to neuter your dog, at least according to what this particular study is suggesting. Neutering males is often performed around 6-9 months in hopes of minimizing marking and humping behaviors.

For female Mi-Kis, particularly if your pup has a high percentage of Shih Tzu in her background, it might be wise to delay her spay until after 24 months.

Since the Mi-Ki is much smaller than the average Shih Tzu, I would not recommend following their suggestion of spaying a female “a month or two before 6 months to avoid the increased risk of cancers.” Mi-Kis are simply too small and vulnerable at 4-5 months of age to undergo such a major procedure.

I’ve even had one client’s girl get so stressed (with a temporary increase in blood sugar level) just doing the pre-surgery bloodwork, that it was determined that she probably wasn’t a good candidate for the elective spaying procedure. Remember, spaying is a major surgery requiring general anesthesia and a two-week recovery period.

Alternatives to Spay and Neuter Procedures

Thankfully, there are more options today for people who prefer less invasive procedures for their dogs while ensuring there are no unplanned pregnancies. There are ovary-sparing spay procedures for females and vasectomies for males that allow dogs to keep their hormones intact.

For a nonsurgical option for males, you can use belly bands to keep them from marking inappropriately. The belly bands also serve as a barrier against breeding but are not foolproof! The use of crates, pens, or separate rooms is also recommended for keeping males and females apart during her cycle.

For females, there are cute small dog underpants to use during her heat cycle. These also provide a secondary barrier against breeding (again, not foolproof!)

Keep in mind that there really isn’t that much discharge with a toy-breed dog during her cycle. You can line both the boy’s and the girl’s undergarments with cut-up sanitary napkins to prevent leaks.

What about the Mi-Ki heat cycle?

Should you and your vet decide to delay your Mi-Ki’s spay, or even forgo the procedure entirely (i.e., for very small Mi-Kis, or those with underlying health issues) you should know that the average female Mi-Ki will cycle every 6-9 months starting at around 9 months of age. The heat cycle will last about three weeks, and one of those weeks, she will be especially fertile and flirty. She must be watched very carefully during her entire cycle to make sure she doesn’t get loose.

The heat cycle shouldn’t ruin your schedule, your camping trip, or anything important. I’ve even had Mi-Ki females in full heat compete in conformation dog shows without much fuss. In fact, Truffle gained her championship with the UKC during her cycle.

Keep your Mi-Ki intact for showing

Speaking of showing, only intact dogs (that are not spayed or neutered) have full options for being exhibited in conformation dog shows. While it is true that there are special classes for altered dogs, neutered dogs won’t be able to compete against unaltered dogs. If you have big plans for showing your dog, it’s best not to spay or neuter them!

It’s a personal decision between you and your vet

The Mi-Ki is its own breed. Although it shares some traits with the Shih Tzu, the Maltese, and other small breeds, your Mi-Ki is probably genetically different enough from the Shih Tzu that it is safe for you to get your female Mi-Ki spayed if that is what you and your vet decide is best for your family. But there may be benefits with neutering alternatives.

Toy breeds mature faster than large breeds, so having your Mi-Ki spayed or neutered in the 6-12 month range will likely not be as impactful health wise as it would be for a slow-growing large breed.

But toy breeds can also be some of the longest-lived dogs, so you’ll want to be sure to discuss this important aspect of your pet’s health with your vet to ensure that all of those years spent together are as vibrant as they possibly can be. Your dog’s hormonal function can be an important piece of the puzzle for your dog’s long-term health. Delaying the spay or neuter until your dog is fully mature allows your dog to develop as nature intended.

We are grateful for the recent studies to help inform our choices in being our pets’ guardians! Find a vet you feel comfortable with who stays current on the latest studies and procedures. Together, you’ll find the best health path for your Mi-Ki.

Our featured image includes our chocolate smooth-face Quigley who lives with Ms. Lisa, and our lovely Isabelle.