Health Effects of Spaying/Neutering Canines
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by Kathy R. Jacobsen

Health Effects of Spaying/Neutering Canines

Are spaying and neutering really the best thing for our canine population? Veterinarians have noted many health issues in dogs that are directly related to early spaying and neutering.  These include diabetes, hip dysplasia, and several types of cancer.  The health of our canine community would benefit greatly by reducing the frequency of spaying and neutering, and educating the public to the alternatives.


In the United States, it is standard practice by veterinarians to perform the procedure of spaying and neutering canines as soon as possible, many times as young as seven weeks of age.  There is evidence that this practice has caused many adverse health effects in canines not previously known. For instance, when compared to the United States, Becker (2013) noted that European countries have a lower rate of altering canines and a lower rate of health issues.

Health Issues

            Evidence shows that spaying and neutering canines cause adverse health effects (Zink, 2005). The information gathered below will show that the younger a canine is altered, the higher the chances are to develop health issues, including cancers, joint disorders, urogenital disorders, vaccine reactions, and diabetes. We will discuss these disorders below.

Unusual Growth Rates

As noted by Zink (2005), young females spayed around seven weeks of age are more likely to have a delay in their growth plates closing.  This will result in abnormal growth patterns.  She also noted that even when veterinarians wait until the female is closer to seven months old, there was still a delay in the closure.  The only time that no delay in the growth plate closure is noted, the female was intact until after the growth plates had closed.  


Lymphoscarcoma is a cancer that attacks the lymph nodes in a dog.  The first sign of this cancer may be a swollen gland.  This cancer travels throughout the body, and if left undetected, it will attack the other organs in the body.  There is virtually no survival with this type of cancer.  Some attempts to put it in remission are successful, but it often only prolongs the suffering. Although this cancer can occur in both altered and unaltered animals, it has shown a higher rate in altered animals (Washington State University, 2014).

Cardiac hemangiosarcoma is a cancerous tumor of the heart. Spayed females are more likely to develop this type of cancer than intact females.  Similarly, neutered males are more likely to develop cardiac hemangiosarcoma than unaltered males (Zink, 2005).  The prognosis of this disease is terminal, and the dog typically lives only another couple of months.

Mast cell tumors are a cancer that can occur anywhere in the body. White, Hohenhaus, Kelsey, and Procter-Grey (2011) note, “A study on cutaneous mast cell tumors (MCT) in several dog breeds, including the Golden Retriever, examined risk factors such as breed, size, and neuter status. Although early versus late neutering was not considered, the results showed a significant increase in frequency of MCT in neutered females; [sic] four times greater than that of intact females.”

Osteosarcoma is a bone cancer in dogs.  It presents as a tumor usually on the front limb near the radius or ulna, a location equivalent to the wrist on a human.  Treatment options for this disease include removals of the tumor, amputation, or chemotherapy.  Some dogs may live up to another year, and some for another two years, but this cancer will result in death (Washington State University, 2014).

Joint Disorders

Hip dysplasia is a hip disease caused when the head of the femur does not fit the hip socket properly.  This disease is very painful and limits the mobility of the animal.  Hip replacement surgery will relieve most of the pain associated with this disease.  Although this disease is often genetic, it is also the result of early altering of the canine (Torres de la Riva et al., 2013).

Cranial cruciate ligament tears are diagnosed at a higher rate in altered animals as opposed to their unaltered counterparts.  These cruciate ligament tears are the most common and  directly linked to the growth plates not closing properly in animals that have been altered (Torres de la Riva et al., 2013). They compare to the human anterior cruciate ligament tear and are repaired with surgery.

Urogenital Disorders

Hormone responsive incontinence is a type of urogenital disorder. Altering a canine removes the source of hormones that help to maintain muscle control of the urethra, which results in the loss of bladder control in older patients (WebMD, 2014). In 2011, the U.S. Food and Drug Administration approved the drug, Incurin, for use in dogs.  This drug will increase estrogen levels and control bladder leakage (FDA, 2011).

      Urinary tract infections are three to four times more likely to reoccur in spayed females than in intact females (Sequin, Vaden, Altier, Stone, & Levine, 2003, p. 1). The cause of most urinary tract infections is E. coli, Staphylococcus, or Proteus species while different types of bacteria in the bladder cause others. Prolonged or frequent urinary tract infections can result in cancer, stress, and bladder stones (PetMD, 2014).

Vaccine Reactions

Reactions to vaccines were more likely to happen to canines that are altered according to a study by Moore, et al., (2005), “Risk was 27% to 38% greater for neutered versus sexually intact dogs and 35% to 64% greater for dogs approximately 1 to 3 years old versus 2 to 9 months old” (p. 1).  Most vaccine reactions are not life-threatening skin issues, such as itching; these reactions respond to anti-histamines and cortisone.   Although rare these reactions can also be life threatening and fatal. All reactions usually occur within the first 12 hours (PetMD, 2014).


A study of spontaneous diabetes mellitus in dogs (Marmor, et al., 1982) found that the “odds ratios by sex adjusted for age and breed indicated significantly (P less than 0.05) elevated risks for entire females and neutered females compared with that for entire males” (p. 1).  This disease affects the pancreas, causing a shortage of insulin, and is controlled by medication.

Geriatric Cognitive Impairment

Neutered canines have an increased risk of contracting geriatric cognitive impairment.  It is much like Alzheimer’s disease in humans: the canine is disoriented both indoors and outdoors.  They change social interaction with the human family members and their sleep cycle can change.  Hart (2001) stated that the lack of estrogen is the main cause of the impairments. The most common symptoms are pacing, panting, or hiding.  Anipryl is a medication used in the treatment Parkinson’s disease in humans, and is effective in the treatment of this disorder in canines (WebMD, 2014  

Alternatives to Altering

The most obvious solution for the owners of canines is to keep their dog away from other dogs when they are in heat. There are other options to altering a canine that are not generally known including vasectomies, hysterectomies, tubal ligations, and hormone suppressors. These procedures are available at your veterinary clinic, but you will have to ask for them.    


A vasectomy on young male dogs leaves the testicles intact, which provides testosterone needed for proper growth. In addition, dogs with vasectomies have lower rates of cancer (Zink, 2005).  This procedure performed on the canine the same way as on a human male by cutting the vasa deferentia tubes and eliminating the pathway for semen.


The alternative for females is to perform a hysterectomy by taking out the uterus, but leaving the ovaries intact, much like the procedure performed on women.  This would prevent the female from becoming pregnant, but still would allow her body to make the necessary hormones that support growth and reduce cancer.  Note that with this procedure, the female will still have her ovaries and still will be at risk for mammary cancers. Owners should be vigilant in checking for lumps, and not allow the female to become overweight for early detection. It is vital to take her to the veterinarian for immediate removal (Zink, 2005).

Tubal Ligation

A tubal ligation performed on the female canine the same way as on the human female.  This procedure cuts the fallopian tubes, leaving the uterus and ovaries in place.  Vetinfo (2012) states, “The procedure is minor, and the recovery is less than 24 hours. The dog will still have heat cycles, but she cannot get pregnant” (p. 1).


The hormone suppressor, Suprelorin, suppresses testosterone in males but can also suppress hormones in females.  An implant is placed just under the dogs’ loose skin between the shoulder blades.  This contraceptive is effective for up to six months and may help control aggressive behavior (Vetinfo, 2012).  The implant is biocompatible, so no removal is required, unless it is necessary to end the treatment (NOAH, 2013).

Proposed Solution

The goal is to reduce the adverse health effects in the canine population, and based on the research presented above, the solution should be to reduce spaying and neutering. This procedure causes health issues such as diabetes, abnormal growth patterns, and cancers. The canine population would benefit by minimizing the use of this procedure.


Results of this research shared with veterinarians during their annual medical conferences would educate them to the alternatives to this procedure.  Armed with the information from this study, veterinarians could place pamphlets in their offices to explain the side effects and the alternatives to this method.  Then pet owners would have the knowledge to make an informed decision about the alternatives.  This type of outreach should lower the rate of adverse health effects in canines; however, if this outreach is not successful, the rate of unwanted side effects will remain unchanged in the canine population.











Becker (2013). This “routine” neutering advice may boost your dog’s risk of cancer and joint disease [sic]. Retrieved from

Cancer in animals (2014). Retrieved from Washington State University

Cancer in animals (2014). Retrieved from Washington State University

Marmor, M., Willeberg, P., Glickman, L. T., Priester, W. A., Cypess, R. H., & Hurvitz, A. I. (1982). Epizootiologic patterns of diabetes mellitus in dogs. American Journal of Veterinary Research, 43(3), 465-70. Abstract retrieved from

Moore, G., Guptill, L., Ward, M., Glickman, N., Faunt, K., Lewis, H., & Glickman, L. (2005). Adverse events diagnosed within three days of vaccine administration in dogs. Abstract retrieved from

National Office of Animal Health (NOAH) (2013). Suprelorin 4.7 mg implant for dogs: Clinical particulars. Retrieved from


PetMD (2014). Urinary Tract Infection, Lower (Bacterial) in Dogs.  Retrieved from

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Sequin, M., Vaden, S., Altier, C., Stone, E., & Levine, J. (2003). Persistent urinary tract infections and reinfections in 100 dogs 1989-1999. PubMed, 17(5), 622-31. Abstract retrieved from

Torres de la Riva, G., Hart, B. L., Farver, T. B., Oberbauer, A. M., McV. Messam, L. L., Willits, N., & Hart, L. A. (2013). Neutering dogs: Effects on joint disorders and cancers in golden retrievers [sic]. Plos One. Retrieved from


U.S. Food and Drug Administration (2011). FDA approves first drug to treat urinary incontinence in female dogs.  Retrieved from:


Vetinfo (2014).  Dog birth control. Retrieved from

WebMD (2014). Cognitive dysfunction syndrome in dogs. Retrieved from


WebMD (2014). Urinary incontinence and bladder problems in dogs comment. Retrieved from

Zink, C. (2005). Early spay-neuter considerations for the canine athlete: One veterinarian’s opinion [Online forum comment]. Retrieved from

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