There are many reasons to think of adding a protection dog to your household. In contemplating the benefits of personal protection dogs you might also consider the long-term health of those dogs. You make all the health care decisions for your dog, everything from decisions about their diet to medical procedures, like sterilization, spay and neuter, our topic today.
Most of us are familiar with the concept of spaying and neutering. It is approved and encouraged by humane societies and animal shelters. However few of us have had factual conversations about the medical risks of these complex desexing procedures. What do you actually know about getting your family protection dog spayed or neutered?
All medical procedures have risks as well as benefits. Surgical sterilization — called spaying (females) or neutering (males) — removes hormone-producing organs which we now know can have detrimental effects on the animal’s overall health. Reproductive hormones are important in growth and development. Research shows that removing the ovaries or testicles at a “pediatric” age increases the potential for health issues later in life.
The following information is an overview of some of the research being done on canine health issues as they relate to sterilization, to help you make an informed decision about key health issues for your protection dog.
Abnormal Bone Growth and Hip Dysplasia
In the early 1990s, medical researchers became aware of the fact that neutering (including spaying) younger protection dogs resulted in taller dogs, compared to those dogs that had been neutered after puberty. The Journal of Pediatric Endocrinology and Metabolism published a study in 2000 offering this explanation: “At puberty, estrogen promotes skeletal maturation and the gradual progressive closure of the epiphyseal growth plate… estrogen has an anabolic effect on the osteoblast and an apoptotic effect on the osteoclast, increasing bone mineral acquisition in an axial and appendicular bone.” In other words, when the estrogen producing organs are removed so are hormones critical to proper bone growth and development, which can result in non-standard sized protection dogs.
Studies at Cornell University’s College of Veterinary Medicine published more than a decade ago, as well as a more recent study published in 2013 for the Canine Health Foundation and the Center for Companion Animal Health at the University of California, Davis show that castrated dogs, are more prone to hip dysplasia. In fact, in the recent study incidence of hip dysplasia was twice as common for male dogs neutered before one year of age, as compared to intact males.
The risk of osteosarcoma is also increased in a surgically sterilized protection dog. Citing examples from earlier studies, a 2002 study from the University of Purdue looked at Rottweilers to examine the link between early neutering and incidences of bone cancer. They found that “Exposure to endogenous sex hormones appears to be protective, as suggested by the high risk for bone sarcoma in male and female dogs that undergo gonadectomy within the first year of life.” An earlier, 1998 study published in the Veterinary Journal also concluded that neutered dogs were 2.2 times more likely to develop bone cancer than intact dogs of their same breeds.
The widely accepted theory that early spaying protects female dogs from breast cancer seems to have been disproved, or at least could not be proven, according to a 2012 study done in the UK and published in the Journal of Small Animal Practice. Researchers from the Royal Veterinary College looking at mammary neoplasia (tumors and abnormal growths in breast tissue) found “evidence that neutering reduces the risk… are weak and are not a sound basis for firm recommendations.” In other words, it is an unproven theory.
The Journal of Veterinary Internal Medicine published a study in 1999 in which researchers had studied over 700,000 dogs, examining the link between neutering and hemangiosarcoma (a type of cardiac tumor). The risk for both male and female dogs was increased. For males only a slight increase but for spayed females, the risk increased to greater than four times the risk of intact females for aortic tumors and a five times greater risk for hemangiosarcoma.
Cranial Cruciate Ligament (CCL) Injuries
Though more common in large breed dogs such as you might choose for personal protection dogs, sterilized dogs of all sizes were shown to have an increased rate of CCL ruptures over intact protection dogs of the same breed according to a study by Texas Tech University Health Sciences Center. Another breed-specific study on Golden Retrievers from 2013 found a 5-8% increase in incidence in dogs that were “fixed” earlier than one-year-old.
Other Health Issues
Studies show that spayed females are 20% more likely to develop urinary incontinence, either shortly after surgery or, in some cases, years later. Early neutering has also been shown to increase incontinence in males. A 2004 study in the Journal of the American Veterinary Association which wanted to favor early neutering admits that with pediatric sterilization “increased urinary incontinence suggests that delaying gonadectomy… may be beneficial.”
The loss of reproductive hormones also causes an imbalance in the endocrine system leading to weight gain and hyperthyroidism. Recent research at Purdue University also suggests that female dogs might live longer if allowed to keep their ovaries. The College of Veterinary Medicine at Texas A&M, in a study of shelter dogs, found that early sterilization led to an increase in contracting infectious diseases.
In addition to the physical health of the animal, there is also the mental health aspect to consider. While there is much research still to be done on the effects of hormone imbalances in dogs, some behavioral issues that have been reported with surgical sterilization include problems like aggression, fearfulness, undesirable sexual behavior, and noise phobia.
There are strong opinions on both sides of this issue, but knowing a few facts about the long-term health effects of sterilization will help you make an informed decision that’s right for both you and your protection dog.