The best time to spay/neuter dogs has been somewhat controversial for several years now. Many veterinarians recommend spay/neuter at 6 months of age, or as soon as the adult teeth have come in.
There has always been a concern that neuterring early made a male dog "smaller" than he would have been had he been neutered later in life. I always found this to be an interesting concern, since there is no way to predict how big the dog "would have been if we hadnt neutered him young"
Most vet have always said that if this was ever a concern, it was maybe a 1/2 inch or so difference in height. To me, that is hardly anything to cause someone to hold off on neutering.
Then, within the last few years there have been some concerns on whether or not spay/neuter before maturity increases the incidence of hip dysplasia and cranial cruciate ligament injuries, as well as some types of cancers.
A very large study (over 1,000,000 dogs) was published in 2008 in JAVMA, one of the leading Veterinary Scientific Journals in the country. What this study found was a significant increase in hip dysplasia and crancial cruciate ligament injuries in altered males and females, as well as a significant DECREASE in the disease after the age of 2.
The study was flawed in that it was what is known as an "andecdotal" study. This means that the study just involved going back and looking over the records of the dogs. There was no control group etc. In other words, the study isnt one that was done using the Scientific Method.
There are many reasons why the dogs in the study could have higher incidences of CCL injuries and hip dysplasia. It could be that more of the altered dogs were obese compared to the unaltered dogs. It could be that the altered dogs had better and more cosistent vet care than the unaltered. It could be a lot of things, but we just dont know. The fact that hip problems were diagnosed less frequently after age 2 doesnt surprise me at all. Usually, if a dog has hip dysplasia that is going to be symptomatic, symptoms begin before age 2. Since most pet owners would only have their dogs checked for hip dysplasia if they were showing problems, it doesnt surprise me at all that the incidence of hip dysplasia appeared to go down after age 2.
To me, there are SO many things about CCL injuries and hip dysplaisa that we cant control, that it makes sense to look at this study and say.....
"Hmmm, it looks like possibly there may be a benefit to spay/neuter later. We dont know for sure WHY, but there seems to be a big increase in hip dysplasia/CCL injuries in dogs that are altered, and there seems to be a big decrease in hip dysplasia diagnosis in dogs after the age of 2.. MAYBE it would be a good idea to wait until the dog is older to neuter/spay."
I now recommend that my puppy parents wait until 12 months of age at a MINIMUM to spay or neuter. If a male, waiting until 18 months to 24 months if possible would be even better.
The problem comes in with managing unaltered dogs.
With a female, you will have to be vigilant to prevent pregnancy. You will also have to put up with 1 possibly 2 heats, depending on when she comes into her first heat, and the age you decide to spay.
With a male, you may start to see some breeding behaviors, humping, etc. This can sometimes be easily stopped simply be corrections, other times it makes for a big problem. With males, you may also start to see dominant behavior toward other males. You may have problems roaming.
It is all a trade off. If you can wait until close to 18-24 months, you MAY decrease the chances of hip/CCL problems, we just dont know.
To me, it is worth the delay if there is a chance it will help the dog avoid hip or CCL probelms in the future.
