Early Spay and Neuter- Evidence Based Challenge

[Julie and Charlie]

Due to a few comments on a topic in "Puppy Madness", I was challenged (encouraged?) to add a discussion about ES&N. I know this topic has been discussed before, but as I see it, many of the opinions are anecdotal--"my dog has this" or "my vet said this" aren't quite what I am looking for.

That said, what are the most recent evidence-based studies and experts saying about the health impacts of pediatric spay and neuter? I honestly haven't seen enough published evidence to sway my opinion either way- perhaps I am not looking in the right places.

Note: I am not trolling for an argument, but trying to gather some well reasoned information from people that I have come to respect a great deal, even though I only know you through your posts on DK.

EDIT: I included the Whole Dog Journal article that got me thinking about this topic.

Whole Dog Journal Article

[Nancy, Ned, Clancy, and Charlie]

What age is considered ESN exactly?

[Cheryl and Finnegan]

ESN or pediatric is defined as spaying/neutering done between 6 and 8 weeks.  However, conventional spaying has been done at 6 months so some refer to anything under 6 months to be an ESN.  My vet suggests that you wait until the dog stops growing.  This differs by the size of the dog.  Small breeds mature sooner and giant breeds take the longest. 

[Nancy, Ned, Clancy, and Charlie]

Thanks, Cheryl. It is funny that we think we know what someone is speaking about but when you are queried as to a detail, you don't know the facts. Suddenly, I realized that I only assumed the age but didn't actually know.

[Barb @ Gemstone Labradoodles]

Current literature indicates that to receive the benefits of later spay and neuter, the dog must have completed growing so approx 1 year of age for small breeds and at least 14 months for large breeds. So 8 weeks or 6 months makes very little difference and most pet owners do not want to go thru heat cycles, not to mention that is illegal in some States. The six month timing was an arbitrary time set many years ago when surgery was much more dangerous than it is now so could not be done safely. The timing was decided to be just prior to the earliest sexual maturity seen in dogs to avoid heat cycles in females and unwanted male characteristics. The AVMA originally gave this advice. Today the AVMA supports ESN. https://www.avma.org/KB/Policies/Pages/Pediatric-Spay-Neuter-Dogs-A...

[Karen, Jasper and Jackdoodle]

The AVMA supports ESN as a way to control population, and not because it is the best thing in terms of health. Their exact wording: 

The AVMA supports the concept of pediatric spay/neuter in dogs and cats in an effort to reduce the number of unwanted animals of these species. Just as for other veterinary medical and surgical procedures, veterinarians should use their best medical judgment in deciding at what age spay/neuter should be performed on individual animals.

I take that to mean that my vet might tell me to wait until my particular dog is 6 or 8 or 12 months of age before neutering. I would like that choice to be made by me and my vet, not a breeder.

Also, in many small breeds, skeletal growth is complete by 6 months of age, not a year. In many larger breeds, including many standard doodles, skeletal growth is complete well before 14 months, often by 9 or 10 months of age. 

[Cheryl and Finnegan]

Here is a fairly complete summary of the risks vs. the benefits of ESN:

http://www.naiaonline.org/pdfs/LongTermHealthEffectsOfSpayNeuterInD...

The vets I consulted from University of Pennsylvania were privately very much against ESN.  I thought that early Hip Dysplasia was my biggest concern.  They informed me that the greater risk my pup faced from Osteosarcoma should scare me more.  That's bone cancer.

Exactly right Karen. Thank you.

[DJ & Chance]

My challenge is understanding what actually counts as ESN. Currently I plan to have Chance neutered next month at 10 months of age. He is a small dog and my vet believes his skeletal growth is completed. But this summary uses one year as the dividing line between ESN and non-ESN.

[Karen, Jasper and Jackdoodle]

10 months is not ESN. And I'm sure that his skeletal growth is complete. Even most purebred full-sized Labrador retrievers reach full skeletal growth by that age. I wouldn't be the least bit concerned about neutering a smaller doodle at this age. 

[DJ & Chance]

Thanks.  Is full skeletal growth the decisive factor?

[Karen, Jasper and Jackdoodle]

For the orthopedic stuff it is. 

[Cheryl and Finnegan]

I would not be concerned about neutering Chance at 10 months. As you said, he's small and his skeletal growth is complete. That is what's important.  That his normal hormones have been present during his growth. 10 months is not ESN for Chance. 

[Karen, Jasper and Jackdoodle]

An excellent article on determining the best age to spay or neuter by Margaret Root-Kustritz, DVM, PhD, University of Minnesota:

http://www.akcchf.org/canine-health/your-dogs-health/determining-th...

Of particular interest from the article:

A very recent study documented change in anatomy of the stifle joint of female and male dogs with CCL injury with gonadectomy prior to 6 months of age; further research is pending. CCL injury is treated with surgery and rehabilitation; treatment is costly and recovery protracted.

(prior to 6 months of age, not a year or 14 months)

 it was demonstrated that spaying before 3 months of age was significantly more likely to be associated with eventual occurrence of urinary incontinence in a given female dog than was spaying later.

(before 3 months of age, not a year or 14 months) 

Lots of other good info in this article that truly presents the benefits and the risks of spay/neuter at various ages.