When Should You Neuter or Spay Your Leonberger

This is a contentious question that can easily lead to heated arguments, which is why I never brought up this issue in my book. I don’t like one-star reviews. A blog post though is a different matter. I can easily delete angry comments as well as the blog post itself.

It is very common for veterinarians and others to recommend that dogs be neutered or spayed between the ages 4-6 months. However, not all dogs are the same and this seems to be bad advice for many giant breeds, especially Leonbergers.

Photo of me with our Leonberger Bronco standing on the sofa.
Is he ready to be neutered? I mean the dog.

With this post I am presenting advice and statements from various sources that I consider to be reliable such as AKC/club certified breeders of the specific breed in question, the corresponding breed organization/club, such as the Leonberger Club of America, and scientists in the specific field. In my experience veterinarians who care for all kinds of dogs and pets typically do not have knowledge that is breed specific enough on this issue.

When we got our late Leonberger Bronco (Le Bronco von der Löwenhöhle) 15 years ago our breeder Julie Schaffert told us to wait with neutering him until he was two years old if possible. Julie Schaffert has been an LCA (Leonberger Club of America) certified breeder since 1992 and is arguably the most prominent Leonberger breeder in North America. A few days ago, I sent her this question:

Hello Julie, I hope all is well with you and your Leonbergers. I am currently reading a Leonberger book by Vanessa Ritchie. I’ve read dozens of Leonberger books. It is a very good Leonberger book. However, in the middle of page 30 she is saying something that concerned me. She is saying to neuter/spay your Leonberger at 6 months old. I remember you telling us to wait with ours and we waited until significantly passed one years old. Assuming that is correct, this mistake needs to be pointed out and perhaps corrected. Before saying anything, I wanted to make sure that is correct, that spaying/neutering at 6 months old is indeed too early for a Leonberger.

Thank you for any help

Happy New Years

Thomas Wikman

This was her answer

Happy new year. Yes, it’s now recommended that giant dogs not be neutered or spayed until after 2 years. In the old days it was recommend earlier any time after 6 months. All the new data says wait.


Black and white photo of our Leonberger Bronco
The Leonberger puppy Julie sold us

A few months ago I participated in an online discussion (Leonberger Facebook group) on this issue and I mentioned that we neutered our Leonberger passed one years old, close to 18 months, but we did not wait two years. There were people who did not like this saying we needed to wait longer. Some people said that 12-18 months was good enough, but they were in general rebutted. The consensus was that you needed to wait two years or not neuter the dog at all if that was practical. Opinions were strong, and I got the feeling that some people felt neutering before the age of two was animal abuse. Whatever you do, don’t discuss this with Leonberger enthusiasts at the Thanksgiving dinner table.

The reasons we did not wait two years was that our veterinarian at the time wanted to do it sooner and Bronco was moving furniture around because of his excess energy. He was strong, energetic and a bit restless. He dragged sofas, chairs and tables around. He was very friendly and harmless, but he had a lot of energy. Perhaps he should have been a home decorator instead of a dog.

Illustration showing that Bronco had pushed our German Shepherd into a storm drain. I am trying to drag/lift the German Shepherd out of the storm drain while holding onto a misbehaving Bronco.
A rambunctious Bronco

So that’s where I was coming from”. In addition to that I searched on-line today to see what people with expertise in the area are saying. I should say that I know enough about internet search not to trust whatever comes up at the top. You need to first consider credentials and expertise.

This one year old article (click here) from the AKC states that a larger or giant breed may need to wait until they are near or over 12-18 months of age before neutering or spaying. The article also provides the following interesting information.

Research conducted by the University of California – Davis reveals that for some dog breeds, neutering and spaying may be associated with the increased risks of certain health conditions such as joint disorders including hip or elbow dysplasia, cranial cruciate rupture or tear, and some cancers, such as lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. The research conclusions are not surprising. Sex hormones are important in the development of any animal.  We know they affect psychological development as well as the musculoskeletal, cardiovascular, and the immune system.

I believe this is the University of California – Davis article in question (click here). It is from 2020. Notice that the suggested guidelines for age of neutering is beyond 23 months for several of the giant breeds in the table of 35 breeds (click here). Also notice that the table does not include Leonbergers.

Hillhaven Leonbergers (click here) in Ireland recommend not neutering until at least 2 years of age. They warn against doing it at 6 months old, despite what some veterinarians may recommend.

I did not find an on-line Leonberger Club of America recommendation but this old 2011 article (click here) from the Leonberger Club of America states: Because the Leonberger is a slow maturing breed in general, most breeders will ask puppy owners to wait a year or so before altering their puppies, to allow bones to develop more fully.

Photo of (left to right) Daisy (Pug), Ryu (Japanese Chin) and Bronco (Leonberger)
Daisy (Pug), Ryu (Japanese Chin) and Bronco (Leonberger)

I did find an article from the Saint Bernard Club of America (click here). The Saint Bernard is genetically similar to the Leonberger. This article states: Above all, no giant breed puppy should be altered before the growth plates in the bones have matured and closed, usually between 15 and 24 months of age.

This Newfoundland dog magazine (click here) states : Currently, the recommended age that a Newfoundland dog should be neutered is 18 to 24 months due to the possible health problems that can arise from altering before that age. The Newfoundland is another dog that is genetically similar to the Leonberger.

So in conclusion, even though the expert advice regarding neutering and spaying is not crystal clear and varies, doing it at six months old is too early and can harm the Leonberger’s health.









Finally, if you would like to learn about more about my book and find out where to buy it, click here or here. You can also click the image below to buy it from

This is an image of the front cover of the book "The Life and Times of Le Bronco von der Löwenhöhle". Click on the image to go to the location for the book.
This is the front cover of the book “The Life and Times of Le Bronco von der Löwenhöhle”. Click on the image to go to the location for the book.