Spay or Neutering Your Mastiff or Other Giant Breed Dog

I wanted to do a quick edit to this specific blog because I think is it a very important topic.  I wanted to add a link to an article recently published by The Dog Place; Rethinking Spay and Neuter.

A lot of new pet owners are under the assumption that they should have their new puppy spayed or neutered by the age of six months.  This timeframe has been preached by vets, animal shelters, rescue organizations and numerous other sources for ages.  The funny thing is that there is no real proof that this is the magic age to alter your pet. 

It is EXTREMELY important that you do not alter your Mastiff until at least 18 months of age, and preferably after 2 years of age.  The growth plates in a giant breed dog are regulated by hormones.  If you chose to remove those hormones by spaying or neutering your Mastiff  prior to completion of growth you are asking for numerous joint, bone and growth issues down the line.

The first thing that can happen is you get a Mastiff that is as tall as a Great Dane and not much wider.  The hormones that tell the growth plates to stop growing upward are removed when the animal is altered, so the bones just keep going up and up. Don't care about appearance?  Check out what else could occur should you chose to alter your pet prematurely.

There is a very good article published by the National Animal Interest Alliance titled Long-Term Health Risks and Benefits Associated with Spay / Neuter in Dogs. (Laura J. Sanborn M.S. May 14, 2007) Here is a summary of the article:

“SUMMARY

An objective reading of the veterinary medical literature reveals a complex situation with respect to the long- term health risks and benefits associated with spay/neuter in dogs. The evidence shows that spay/neuter correlates with both positive AND adverse health effects in dogs. It also suggests how much we really do not yet understand about this subject.

On balance, it appears that no compelling case can be made for neutering most male dogs, especially immature male dogs, in order to prevent future health problems. The number of health problems associated with neutering may exceed the associated health benefits in most cases.

On the positive side, neutering male dogs  

•eliminates the small risk (probably <1%) of dying from testicular cancer
•reduces the risk of non-cancerous prostate disorders
•reduces the risk of perianal fistulas
•may possibly reduce the risk of diabetes (data inconclusive)

On the negative side, neutering male dogs  

•if done before 1 year of age, significantly increases the risk of osteosarcoma (bone cancer); this is a common cancer in medium/large and larger breeds with a poor prognosis.
•increases the risk of cardiac hemangiosarcoma by a factor of 1.6
•triples the risk of hypothyroidism
•increases the risk of progressive geriatric cognitive impairment
•triples the risk of obesity, a common health problem in dogs with many associated health problems
•quadruples the small risk (<0.6%) of prostate cancer
•doubles the small risk (<1%) of urinary tract cancers
•increases the risk of orthopedic disorders
•increases the risk of adverse reactions to vaccinations

For female dogs, the situation is more complex. The number of health benefits associated with spaying may exceed the associated health problems in some (not all) cases. On balance, whether spaying improves the odds of overall good health or degrades them probably depends on the age of the female dog and the relative risk of various diseases in the different breeds.

On the positive side, spaying female dogs 

•if done before 2.5 years of age, greatly reduces the risk of mammary tumors, the most common malignant tumors in female dogs
•nearly eliminates the risk of pyometra, which otherwise would affect about 23% of intact female dogs; pyometra kills about 1% of intact female dogs
•reduces the risk of perianal fistulas
•removes the very small risk (0.5%) from uterine, cervical, and ovarian tumors

On the negative side, spaying female dogs
•if done before 1 year of age, significantly increases the risk of osteosarcoma (bone cancer); this is a common cancer in larger breeds with a poor prognosis
•increases the risk of splenic hemangiosarcoma by a factor of 2.2 and cardiac hemangiosarcoma by a factor of >5; this is a common cancer and major cause of death in some breeds
•triples the risk of hypothyroidism
•increases the risk of obesity by a factor of 1.6-2, a common health problem in dogs with many associated health problems
•causes urinary “spay incontinence” in 4-20% of female dogs
•increases the risk of persistent or recurring urinary tract infections by a factor of 3-4
•increases the risk of recessed vulva, vaginal dermatitis, and vaginitis, especially for female dogs spayed before puberty
•doubles the small risk (<1%) of urinary tract tumors
•increases the risk of orthopedic disorders
•increases the risk of adverse reactions to vaccinations

One thing is clear – much of the spay/neuter information that is available to the public is unbalanced and contains claims that are exaggerated or unsupported by evidence. Rather than helping to educate pet owners, much of it has contributed to common misunderstandings about the health risks and benefits associated of spay/neuter in dogs.

The traditional spay/neuter age of six months as well as the modern practice of pediatric spay/neuter appear to predispose dogs to health risks that could otherwise be avoided by waiting until the dog is physically mature, or perhaps in the case of many male dogs, foregoing it altogether unless medically necessary.

The balance of long-term health risks and benefits of spay/neuter will vary from one dog to the next. Breed, age, and gender are variables that must be taken into consideration in conjunction with non-medical factors for each individual dog. Across-the-board recommendations for all pet dogs do not appear to be supportable from findings in the veterinary medical literature.”

A few other statistics I pulled from the article in regards to early spay or neuter and the correlation of Osteocarcenoma are as follows:

“A multi-breed case-control study of the risk factors for osteosarcoma found that spay/neutered dogs (males or females) had twice the risk of developing osteosarcoma as did intact dogs.”

“The researchers suggest a cause-and-effect relationship, as sex hormones are known to influence the maintenance of skeletal structure and mass, and also because their findings showed an inverse relationship between time of exposure to sex hormones and risk of osteosarcoma.”

“Given the poor prognosis of osteosarcoma and its frequency in many breeds, spay/neuter of immature dogs in the medium/large, large, and giant breeds is apparently associated with a significant and elevated risk of death due to osteosarcoma.”

Some other important health aspects related to early spay/neuter are the increased risk of obesity, spay incontinence in female dogs, increased risk of vaccine reactions and other orthopedic issues.

I recommend that any pet and specifically giant breeds such as Mastiffs are NOT to be altered before they are 18 months of age for these reasons.  When it comes to the lifelong health of your pet these highly increased risks are just not worth taking.