Tuesday, July 22, 2014

Spaying and Neutering

Most people in the US, if asked, would tell you that, absolutely, you should spay or neuter your dog. They would tell you there are already too many unwanted dogs out there, they might also tell you that it is healthier.

 There is recent research out there suggesting that spaying and neutering, especially early (under 6mos) is actually a detriment to your pet's health. In Norway it is actually illegal to castrate your dog.

This study on Goldens was released last year:
Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers

"As for the pathophysiological reasons for the joint disorders, one can point to the role of gonadal hormones in controlling the closure of bone growth plates [23], [24]. An atypical growth plate closure, resulting from the absence of gonadal hormones, may increase the chance of a clinically apparent joint disorder, such as HD, CCL, and possibly ED. Confounding factors that may influence the nature of a neuter-related joint disorder are the breed-specific gender vulnerabilities, including growth rate differences, as well as the timing of growth plate closure, which occurs more quickly in males than in females. In the males of this study, the occurrence of HD was doubled in the cases with early androgen removal as compared with intact males, but in females, removal of the ovaries did not appear to be associated with an increased likelihood of HD. This presumably reflects the effect of gender on growth-plate development. However, growth-plate disturbance in both males and females seems to have played a role in the occurrence of CCL in early-neutered dogs. This joint disorder was not diagnosed in either intact males or females. The mean age of CCL onset was later in life than in HD (about 4 years and 2 years, respectively)."

Initially when I read this study I thought "Of course, you are doing a study on dogs who get cancer anyway!" But the point of the study is not that these dogs are prone to these problems, the point of this study is there an increased risk when you alter the dogs.

Here is a study released this year on Labs and Goldens:
Long-Term Health Effects of Neutering Dogs: Comparison of Labrador Retrievers with Golden Retrievers

"A study utilizing the Veterinary Medical Database of over 40,000 dogs found that neutered males and females were more likely to die of cancer than intact dogs, especially of OSA, LSA and MCT [15]. This study included no information on age of neutering. The most recent publication in this area is a study of Vizslas utilizing owner-reported disease occurrence in an online survey, in which the incidence of cancers was reported higher in neutered dogs than in intact dogs [16]. The main cancers related to neutering were LSA, HSA and MCT. The occurrence of MC was very low in females left intact.
With regard to joint disorders, one study of effects of neutering in larger breeds documents a 3-fold increase in excessive tibial plateau angle – a known risk factor for development of cranial cruciate ligament tears or rupture (CCL) [17]. Across several breeds, a study of CCL found that neutered males and females were 2 to 3 times more likely than intact dogs to have this disorder [18]. Neither study examined early versus late neutering with regard to this disorder. The study from this center of neutering in Golden Retrievers (mentioned above with regard to cancers [14]) included examination of joint disorders. Of the early-neutered males, 10 percent were diagnosed with hip dysplasia (HD), double the occurrence of that in intact males. There were no cases of CCL diagnosed in intact males or females, but in early-neutered males and females the occurrences were 5 percent and 8 percent, respectively."

Here is a study on Vizslas:
Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas 

"The Vizsla study involved 2,505 dogs, and reported these results:
  • Dogs neutered or spayed at any age were at significantly increased risk for developing mast cell cancer, lymphoma, all other cancers, all cancers combined, and fear of storms, compared with intact dogs.
  • Females spayed at 12 months or younger, and both genders neutered or spayed at over 12 months had significantly increased odds of developing hemangiosarcoma, compared with intact dogs.
  • Dogs of both genders neutered or spayed at 6 months or younger had significantly increased odds of developing a behavioral disorder, including separation anxiety, noise phobia, timidity, excitability, submissive urination, aggression, hyperactivity, and/or fear biting. When it came to thunderstorm phobia, all neutered or spayed Vizslas were at greater risk than intact Vizslas, regardless of age at neutering.
  • The younger the age at neutering, the earlier the age at diagnosis with mast cell cancer, cancers other than mast cell, hemangiosarcoma, lymphoma, all cancers combined, a behavioral disorder, or fear of storms.
  • Compared to intact dogs, neutered and spayed dogs had a 3.5 times higher risk of developing mast cell cancer, regardless of what age they were neutered.
  • Spayed females had nine times higher incidence of hemangiosarcoma compared to intact females, regardless of when spaying was performed, however, no difference in incidence of this type of cancer was found for neutered vs. intact males.
  • Neutered and spayed dogs had 4.3 times higher incidence of lymphoma (lymphosarcoma), regardless of age at time of neutering.
  • Neutered and spayed dogs had five times higher incidence of other types of cancer, regardless of age of neutering.
  • Spayed females had 6.5 times higher incidence of all cancers combined compared to intact females, and neutered males had 3.6 times higher incidence than intact males."

I know this might be a lot to take in and understand. I myself am still drawing my own conclusions. From what I have been reading I think it's important to realize that nothing is completely certain yet. There are not enough studies to conclude that your pet is completely safe from cancer/other issues if you keep them intact. However, most research is reporting that dogs are healthier with their hormones.

I met my friend Kay about a year ago. She has three intact dogs, two females and a male - all apbt. Something that I will never forget is when she pointed out to me that just because someone has intact dogs doesn't mean they will breed them. I never thought if it so plainly. I mean, I have friends who have intact dogs that they show - but at the time, in my mind, I felt if you weren't showing your dogs your dogs should be spayed or neutered. When she told me so plainly that "just because" it really made me realize how right she was. The majority of people who choose to keep their dogs intact for health reasons are not irresponsible people.

It still has been hard for me to wrap my head around and until I talked to this group: FB OSS and Vasectomy Info Group

They have answered my questions kindly and I often read the discussions other folks have. I have decided that for my next dog - male or female, I will wait until my dog is at least 2yrs of age before altering. If I have a male, I may not neuter at all. If I have a female at the very least I would remove the uterus, but I would probably do a traditional spay - only because at this point I have no desire to deal with heat cycles. My mind may change later. I have never owned an intact dog before so I have no idea what it will be like. Talking to other people it seems safer for males to be left intact than for females because females risk Pyometra. However it sounds like most people still wait until their females are over the age of 4 to spay their dogs, if they go through with a complete spay.

One interesting personal note as well is that all of the dogs we have treated for lymphoma/lymphosarcoma at work have all been dogs who have been spayed/neutered.

I hope to keep this post updated as more studies come out. It is still very new research, but it makes sense to me that hormones are important. In people they do not remove testicles from men unless medically necessary and in women it is nearly impossible to have your uterus removed unless it's medically necessary. While I know humans can communicate emotional distress, dogs cannot, and if plays such a huge role in people - I can only imagine it is similar in dogs.


  1. With all the new studies that are coming out it makes me kind of nervous! LOL! I am certain that next dog will not be spayed until fully mature..

    1. After talking with the folks on the one group there is a genetic component to cancer so leaving them intact is not the be all end all, but it is SO taboo in human medicine to have your uterus taken out if you are a woman. I always thought it was related to emotional distress or possible 'what ifs' if a woman later wants to have a kid. But I think there is a major health component also.

      I will definitely wait for my next dog... like I said I might even consider an alternative surgery but we will wait and see. Dealing with an intact male wouldn't be such a big deal, but dealing with an intact female would suck - esp if she got pyo.