IEEE BERKSHIRE SECTION - High School STEM Research Challenge 2022

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               IEEE
         BERKSHIRE SECTION

High School STEM Research Challenge – 2022

             “To Spay, Or Not To Spay”

                         Written for:
 The Institute of Electrical and Electronics Engineers, Inc.
                     Berkshire Section

                 STEM Research Contest

                             By

                     EMMA ADELSON
                      75 SUMMER ST
                          LEE, MA
                           01238

                         2/23/2022

                  MISS HALL’S SCHOOL
                       GRADE 12
                    DONNA DAIGLE

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                                   “To Spay, Or Not To Spay”

A gonadectomy, most commonly known as a spay or neuter, is one of, if not the most frequent

veterinary procedure. This simple surgery has become muscle memory for veterinarians across

the United States. While always presented to animal owners as beneficial, new, and ongoing

research surrounding a multitude of dog breeds suggests a slightly different idea. The

gonadectomy does hold a variety of positive outcomes, but an exploration of long-term negative

effects has presented a sudden conflict in the veterinary world.

Before uncovering recent complexities surrounding the gonadectomy, it is vital to understand

this surgery at a basic level. A spay/neuter is a veterinary surgical procedure to remove an

animals sex organs. A neuter involves the removal of the animal's testes, while a spay involves

the removal of an animal's ovaries, fallopian tubes, and uterus. This procedure originally gained

popularity as animal overpopulation began causing increased issues across the United States. Pet

owners rely on this surgery frequently due to its connection to preventing behavioral issues

attached with an animal's heat cycle. Many states now hold requirements for shelters to

spay/neuter all dogs and cats who pass through their adoption agencies. A recent estimate

displays over 80% of U.S. dogs have received a gonadectomy (Bentley and Thalheim). However,

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as previously mentioned, medical irregularities have recently been discovered, linking the

question: is the easiest answer, always truly the best?

Dr. Benjamin Hart has pioneered this ongoing research,

finding the most prominent factors of negative outcomes

being time frame, sex, and breed. Hart's research,

beginning in 2013, initially focused on the gonadectomy

of the Golden and Labrador Retriever. His research

followed a 13-year time frame of hospital records for                     (“Spay and Neuter”)

dogs the ages of: prior to six months, six to eleven

months, during year one, and years two through eight. Dr. Hart’s findings displayed that the

breed was three to four times more likely to develop hip dysplasia and cranial cruciate ligament

damage when spayed/neutered (Hart et al.). A Cornell University study also furthered Dr. Hart’s

focus on Golden Retrievers, focusing more on how time frame contributes to these prolonged

joint issues. The team found that for Goldens spayed/neutered prior to one year, the CrCl rupture

risk was 5% for male dogs, and 8% for females; this being higher than both intact and neutered

dogs after one year of age. An eight-year study specifically targeting Boxers discovered a similar

connection between dog’s age when receiving a gonadectomy, and hip dysplasia. Boxers that

had been diagnosed with hip dysplasia within six months of their spay or neuter were 1.5 times

more likely to also develop significant lameness later in life (Howe). The Cornell team also

found that in-surgery complications were more commonly occurring in dogs older than 2 years

of age (Bentley and Thalheim). This focus on joint issues, while commonly not fully detrimental

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towards a dog's physical health, can be both mentally harmful towards the animal, and become a

financial burden on the owners.

After discovering this negative correlation, Dr. Hart expanded his work to include a range of 35

different dog breeds and around two thousand dogs. Preliminary research found that dog breeds

weighing less than 20 kilograms, with the unusual exception of Shih Tzu, did not experience

these long-term joint issues found in the Retrievers. However, inconsistencies remain in the

research surrounding joint issues in dogs weighing more than 20 kilograms (Hart et al.). Dr.

Hart’s research varied in this category, more heavily relying on factors such as sex and specific

breed. Interestingly, Dr. Hart’s research disproved the common idea that neuters, while being a

preventative for testicular cancer, are also a preventive for prostate cancer. His work notes that

“prostate cancer in males is more common in neutered than intact dogs” (Hart et al.). This

increased development of prostatic carcinoma is due to the connection between androgen

deprivation and increased tumor progression (Bentley and Thalheim). His research did come to a

conclusive commonality that the long-term health issues were mostly limited towards dogs

spayed/neutered prior to reaching sexual maturity. This larger study also found that early age

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gonadectomy in female dogs showed a notable increased risk of urinary incontinence and

cystitis. Another discovery found that castrated female and male dogs have also been showing an

increased development of transitional bladder cell carcinoma. Female dogs have shown a higher

risk than males with an approximate ratio of [1.8:1] (Bentley and Thalheim). While

inconsistencies are bound to appear at this early stage of research, the broad range of health

concerns is raising red flags in the veterinary profession.

While the negative seems to prevail, the positive outcomes of the gonadectomy are still firmly

present. Hormones heavily affect the development of tumors; castration takes away the risk of

testicular cancer in male dogs, and ovarian removal shows a highly negative effect on the

development of mammary tumors (Rozenbaum). In females, the release of sex hormones by the

ovaries can cause many diseases, including uterine pyometra and vaginal hyperplasia; spays are

highly effective in preventing such issues. Spays have also shown a significant reduced risk of

adenocarcinomas in female dogs, as over 60% of adenomas are found in the sexual organs.

Cornell's research found that neuters do help prevent: orchitis, neoplasia, and perineal hernias.

While spays help prevent: neoplasia, and mammary neoplasia (Bentley and Thalheim). This

procedure is still a viable and responsible course of action for many pet owners, as long as the

possible concerns are known.

There are proven pro’s, and unfortunately, newly proven cons to this routinely done procedure.

However, it is vital to reinforce that this work is ongoing. Finding consistencies and/or concrete

trends in data will be difficult until further research continues. Continuing to explore how a dog’s

age, breed, and sex intersect with long-term health issues is incredibly important to create a

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healthier, and sustainable future for our loved pets. While the many possibly harmful outcomes

remain a possibility, it is imperative that population control still be taken seriously; overcrowded

shelters and overwhelmed pet owners can create their own multitude of issues. As an aspiring

veterinarian I believe that while firm conclusions are still in the research phase, the current

institutionalized change must lie in doctor-to-patient communication. This procedure should

become a longer conversation with pet owners, discussing each factor and possible outcome. The

discussion surrounding the possible financial responsibility of extended veterinary care is also a

form of population control, allowing pet owners to make a conscious decision surrounding their

ability to care and love for these animals. While the best solution may no longer be what is

considered the easiest, these incredible companions deserve informed decisions as their health

remains in our hands.

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                                          Works Cited

Bentley, Adrienne, DVM, DACVS, and Lindsay Thalheim, VMD, DACVIM (Onc).

       "Controversies in Spaying and Neutering: Effects on Cancer and Other Conditions."

       Cornell University Veterinary Specialists, www.cuvs.org/sites/default/files/inline-files/1-

       4%20Bentley%20Thalheim%20-%20SpayNeuter.pdf. Accessed 8 Feb. 2022.

Hart, Benjamin L., et al. "Assisting Decision-Making on Age of Neutering for 35 Breeds of

       Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence." Frontiers in

       Veterinary Science, vol. 7, 7 July 2020, https://doi.org/10.3389/fvets.2020.00388.

       Accessed 8 Feb. 2022.

Howe, Lisa M. "Current Perspectives on the Optimal Age to Spay/Castrate Dogs and Cats."

       Veterinary Medicine (Auckland, N.Z.), vol. 6, nos. 171-180, 8 May 2015,

       https://doi.org/10.2147/VMRR.S53264. Accessed 28 Feb. 2022.

Rozenbaum, Mia. "The Benefits and Risks of Neutering Pets." Understanding Animal Research,

       25 Feb. 2020, www.understandinganimalresearch.org.uk/news/research-medical-

       benefits/neutering-and-cancer-the-good-the-bad-and-the-ugly/#. Accessed 8 Feb. 2022.

"Spay and Neuter." Tri-County Veterinary Service, www.tricountyvetservice.com/services/spay-

       neuter/. Accessed 2 Mar. 2022. Infographic.