Before her first heat cycle, usually around five to six months. The research on this particular breed is thinner than I would like — so this page is partly about how I reach a confident answer anyway, which is not by pretending the data is stronger than it is.
The Maltese section of the big neutering study found nothing. No joint disorders in any group, one single cancer case among the intact females, and no urinary incontinence at all. On the face of it, that settles the question.
Except that it rests on 272 dogs, which is the smallest sample of any breed I have written up here — and elsewhere on this site I spend entire pages explaining why a null result from a small group should not be trusted.
So I owe you an explanation rather than a double standard. I am confident about the Maltese, and it is not because of the Maltese data.
It is because the Chihuahua was studied in over a thousand dogs and came back null, and the Yorkshire Terrier in nearly seven hundred and came back null. Three small breeds of much the same size and build, analysed separately, all pointing the same way.
— Dr. P
That is a legitimate way to reason, and it is how a lot of medicine actually works when one dataset is thin. It is also exactly why I do not extend the same courtesy to a Standard Poodle.
What the research actually shows
The Maltese is one of the 35 breeds in the UC Davis neutering study, with 65 intact and 86 spayed females inside a total of 272 dogs. Joint disorders showed no occurrence in intact or spayed dogs of either sex. Cancers amounted to a single case among the intact females and essentially nothing elsewhere. Urinary incontinence did not occur in any female. The guidance for both sexes is that those wishing to neuter should decide on the appropriate age.
Eighty-six spayed females across four age bands is roughly twenty dogs per band — small enough that a real risk of several percent could produce zero cases by chance. On its own, that null proves little.
But it does not stand on its own. The Chihuahua was studied in 1,037 dogs and found nothing. The Yorkshire Terrier, 685 dogs, also nothing. When several separate samples of very similar dogs all come back the same way, the combined picture is far stronger than any one of them.
Why I do not do the same for a Standard Poodle. On that page I look at a similarly clean null and still recommend waiting, and the difference is twofold. There was no large sample of comparable dogs saying the same thing. And there is a plausible mechanism arguing back — removing hormones before the growth plates close lets the long bones grow slightly longer and changes joint angles, which a fifty-to-seventy-pound frame then carries for a decade. In a seven-pound Maltese there is very little load for that mechanism to act on.
Weak evidence plus a plausible mechanism means caution. Weak evidence plus corroboration, with no mechanism to worry about, means I can give you a straight answer.
So what does decide it?
Mammary tumours. Spaying before the first heat is associated with substantially lower mammary tumour risk than spaying after one or two cycles, and the protection falls away with each cycle. Mammary tumours are among the more common cancers in intact female dogs and a meaningful share are malignant. In this breed nothing stands against going early.
Pyometra. An infection of the uterus that affects intact females, usually in middle age and often in the weeks after a heat. It makes them dangerously ill, and treating it means emergency abdominal surgery on a sick older dog rather than a planned procedure on a healthy young one. In a seven-pound patient that is a situation worth removing from the board entirely.
What I recommend
Where I deviate. If she is genuinely tiny or still immature at five months, a few more weeks is fine — I would rather operate on a puppy who is thriving than hit a date. If she has already come into her first heat, we wait until it has finished and things have settled, usually two to three months. And if I find a heart murmur or a luxating kneecap on her exam, we work out what it means before scheduling rather than after.
No honest veterinarian can hand you an exact date without meeting your dog. Bring her in and we will settle it together.
How I do the surgery
At her size this is the least consequential decision on the page. The laparoscopic advantage is largest in big dogs, where a conventional spay means a long abdominal incision and keyhole access spares much of it. On a seven-pound Maltese the traditional incision is already very small and the recovery already quick, so the gap narrows a long way. It remains a gentler operation with less tissue disturbed and plenty of families choose it for that reason — I simply will not tell you it changes her outcome the way it changes a seventy-pound dog's.
What the day looks like
She comes in that morning after a shorter fast than you may have been told, has pre-anaesthetic bloodwork and an IV catheter, and is monitored continuously on a warming system — a dog this small has almost no thermal reserve, her glucose is watched, and her drug doses are calculated precisely rather than scaled by eye. I do the surgery myself; I have been a solo veterinarian since 1998, so the person who examined her and the person holding the instruments are the same person.
She goes home the same day with pain medication, closed with absorbable suture and surgical glue, so there is nothing to remove later. While she is asleep I will check her mouth for retained baby teeth, which the toy breeds keep more often than not. More detail on the day itself is on what to expect from your pet's surgery.
Maltese spay questions
On its own, not much — and I would rather admit that than pretend otherwise. Eighty-six spayed females split across four age bands leaves roughly twenty dogs in each, and a group that size can return zero cases even when a genuine risk of several percent exists. So if the Maltese data were all I had, I would treat it as weak. What makes me confident anyway is that I do not have to rely on it alone. The Chihuahua was studied in a sample of over a thousand dogs and came back null. The Yorkshire Terrier, nearly seven hundred, also null. Three small breeds of the same size and build, examined separately, all pointing the same way. That agreement is worth more than any one of them.
Because two things are different there and both matter. First, there was nothing comparable to borrow from — no large sample of similar dogs saying the same thing, the way the Chihuahua data supports the Maltese. Second, there is a plausible mechanism arguing back in a big dog: removing hormones before the growth plates close lets long bones grow slightly longer and changes joint angles, and a fifty-to-seventy-pound frame carries those altered angles for a decade. In a seven-pound Maltese there is very little load and very little leverage for that mechanism to act on. Weak evidence plus a plausible mechanism means caution. Weak evidence plus corroboration and no plausible mechanism means I can relax.
The two benefits that were never in dispute. Spaying before the first heat is associated with substantially lower mammary tumour risk than spaying after one or two cycles, and that protection erodes with each cycle she goes through. And it removes the possibility of pyometra, an infection of the uterus that typically strikes middle-aged intact females and turns a healthy dog into an emergency — which in a seven-pound patient is something I would much rather prevent than treat. With the orthopaedic side of the scale genuinely empty, both point the same way.
Usually not, though I would rather look at her than answer from a chart. What being small changes is how carefully everything is managed: she has almost no thermal reserve so she is on a warming system throughout, her blood glucose is watched, and her drug doses are calculated precisely rather than scaled by eye. Her fast beforehand is shorter than people were once told, because a very small young dog can drop her blood sugar if she goes too long without food. If she is at the tiny end even for a Maltese, tell me and I will plan her day around it.
No, and there is nothing to make up for. Mammary protection is strongest before the first heat and declines with each subsequent cycle, but it declines gradually rather than switching off, and a dog spayed after one cycle is still considerably better off than one left intact for years. The pyometra risk ends entirely on the day she is spayed regardless of how many cycles she has had. I would book her now rather than wait for another one, because time passing is the only thing that changes the arithmetic from here.
It is where the benefit is smallest, and I would rather tell you that than sell it. The strongest case for the laparoscopic approach is in large dogs, where a conventional spay means a long abdominal incision and the keyhole approach spares a great deal of it. On a seven-pound Maltese the traditional incision is already very small and the recovery already quick. It is still a gentler operation with less tissue disturbed, and some families choose it for exactly that reason — but it does not transform her outcome the way it transforms a seventy-pound dog's.
Keep reading
Every breed grows on its own schedule. If one of these is closer to your dog, start there.
Your Maltese, the other half of the question:
Similar-size breeds:
The whole picture: read the veterinarian's breed-by-breed spay and neuter guide, or see how the laparoscopic spay works.
Bring her in around four or five months and we'll check her over, confirm the timing, and get her on the schedule before her first heat.
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