Episode 74: Rethinking Spay/Neuter with Dr. Chris Zink

This episode is an adaptation of a webinar we had with Dr. Chris Zink. Dr. Zink introduces a new survey looking at how reproductive status affects health outcomes in dogs. We’re interested in learning more about alternatives to spay/neuter surgery, but we need ALL dog owners to participate. You can fill out the survey HERE!

Dr. Zink wears many hats. She is a veterinarian who specializes in canine sports medicine. She is the owner of Canine Sports Productions and competes in several dog sports including Agility, Obedience, Conformation, and Rally. Dr. Zink is an accomplished researcher and author of dozens of scientific papers. She is the Director of Molecular and Comparative Pathobiology and a Professor at Johns Hopkins School of Medicine. And we are very grateful to say that she also takes time out of her very busy life to serve on Good Dog’s Advisory Board!

Transcript

Mikel Delgado [0:25] I am Dr. Mikel Delgado. I am Good Dog’s Standards and Research Lead. We’re here today with Dr. Chris Zink, so thank you everyone for joining us. We’re really excited to have her. Just to tell you a little bit about Good Dog before we dive in: Good Dog is on a mission to build a better world for our dogs and the people who love them by advocating for dog breeders, educating the public, and promoting canine health and responsible dog ownership. We are a secure online community created just for dog breeders, and we are completely free for dog breeders, too. If you aren’t yet a member of our community, we invite you to learn more about our mission and apply to join at www.gooddog.com/join. I’m going to start off by handing things over to Dr. Judi Stella. She is going to introduce Dr. Chris Zink, so Judi?

Judi Stella [1:14] Welcome, everyone! We’re really happy today to announce the launch of Good Dog’s first research collaboration. One of the most important aspects of our mission is stressing the importance of health as a pillar of dog wellbeing. As a technology company, we recognize the potential for revolutionary insights and progress in canine health that recent technological and scientific advancements have made possible. The possibilities for these groundbreaking advancements, however, are dependent upon collaboration between breeders, veterinarians, scientists, and members of the public who care for and love dogs. This research project is the first of many that Good Dog is planning in the years to come. We hope that you will join us in our search for answers, so we can build a better world for our dogs. With that, I’m excited to introduce our esteemed colleague and collaborator on this project, Dr. Chris Zink. Dr. Zink has spent her career as a research scientist at the John Hopkins School of Medicine, focusing on the response of the immune system to retroviruses, such as HIV. She is also a world-renowned expert in canine sports medicine and rehabilitation. Dr. Zink was instrumental in establishing the American College of Veterinary Sports Medicine and Rehabilitation, as one of the newest specialties in veterinary medicine, and was named Outstanding Woman Veterinarian of the Year in 2009. She is the award-winning author of numerous books and co-editor of the first-ever textbook on canine sports medicine and rehabilitation. Welcome, Dr. Zink! And Dr. Delgado, go ahead and take it away. 

Chris Zink [2:38] Hello, everybody! 

MD [2:39] Thank you, Dr. Zink, for being here! So excited to launch this project. Obviously Judi just gave us a really nice introduction to you and your background on all these amazing things you do, but can you tell me how you got interested in questions around spay/neuter and alternatives for dogs? Like, how did you get from your work at Johns Hopkins and your work in canine sports to the questions of spay and neuter?

CZ [3:01] It actually turns out to be kind of a personal story. Many, many years ago—actually, 1985—I was getting a Golden Retriever, and I had a choice between two of them that looked very similar and seemed very similar, behaviorally and temperamentally and everything. So I picked one. And when they were two years old, I met the one that I hadn’t picked, and it didn’t really look like a Golden Retriever. It was long-legged. It was skinny. It had a narrow head. It had a fluffy, weird coat that floated out from the sides. And I thought to myself: Man, I really picked the right one! I don’t know why this one ended up being that way. But over time, it started to dawn on me that that was because that dog had been neutered at 6 months and my dog was intact. I began to think about the whole thing, about what the gonads really are for, and I started to realize that the ovaries and the testicles are not just about reproduction, but rather that they have many, many functions across the body. The more I thought about it, and the more that I read about it, I started gathering data and realizing that perhaps there were other ways to prevent a dog from breeding—other than removing their gonads. And of course there are. So I started to gather the data and encourage people—and actually published some papers on my own about the subject, encouraging people to really think a little bit more deeply about this subject: that we shouldn’t just be performing mass veterinary medicine on all dogs without thinking more broadly about the consequences. 

MD [4:35] And it can be a controversial topic, depending on what circles you run in, I’m sure. Did you face any resistance when you started publishing?

CZ [4:42] Oh, I really did! I really did. I think the two main groups that I faced a lot of resistance from were veterinarians and rescue organizations or shelter groups. It’s been tough, a little bit, to be really honest, sometimes—especially with my veterinary colleagues. But I, for a long, long time, believed what I was taught in veterinary school without really questioning it. But I think what’s happened in the last probably 10 years (maybe 15 years), there have been more and more publications and studies looking into this question by not just me anymore, but by other scientists and veterinary schools, such as UC–Davis. So I think we’re at a point now where there’s an accumulation of data that, if we really are responsible, we need to think about what all that data means and some of the alternatives that are available to people to prevent reproduction, if that’s their choice.

MD [5:38] That’s a great point. So, you mentioned your journey. You learned about these alternative procedures. You hinted at this, but why should someone consider a vasectomy or an ovary-sparing spay as opposed to just not leaving their dog intact?

CZ [5:51] The gonads—of course they produce the eggs and the sperm, but they also produce hormones. Estrogen/testosterone being the ones we think about most, but there are others as well. And the interesting thing about the endocrine system is that the entire endocrine system in the body is a series of feedback loops, so the pituitary makes some hormones that tell the ovary to do something. And the ovary produces hormones. And then those feed back to the pituitary. And the pituitary slows down on what it’s producing. Over time, there were a number of things I noticed. One of the things was this whole thing about “this littermate of mine; why did he look so different?” He looked that different because we know that testosterone and estrogen are responsible for stopping growth. If we remove the testosterone and estrogen, growth continues, but because the growth of various bones stops at different times, that continued growth tends to make a dog an abnormally-shaped dog. You might think to yourself: Well, what does that matter? But one of the things that I started to notice were there were more and more publications and, in fact, there are 8 publications out now showing that dogs that were spayed or neutered have more cranial cruciate ligament rupture. That’s an issue that’s a big deal for people. That’s a very costly surgery. If you don’t do the surgery, then the dog is going to develop arthritis and have a lifetime of pain and discomfort. So that was a big one. And then there started to surface, these publications showing that dogs that were spayed or neutered (and honestly it didn’t even matter what age they were spayed or neutered at) had a higher incidence of a variety of cancers and, in particular, fatal cancers, like hemangiosarcoma, lymphoma, osteosarcoma, transitional cell carcinoma, etc. I actually published a study in Vizslas (and others have published studies looking at this in Golden Retrievers, Labrador Retrievers, German Shepherds, and other breeds). That started to really hit home. But one of the things that really got me worried was that in my study, in Vizslas, not only did dogs get more cancer if they were spayed or neutered (regardless of the age they were spayed or neutered) but it happened at a younger age. Now that starts to really be meaningful. Because every Golden Retriever I’ve had has died of cancer. But one of my last Golden Retrievers died at 15.5 of liver cancer. So, I’m okay with that! We all have to go! But I have friends who have had dogs die of hemangiosarcoma at 3 or 3.5 years of age, before the prime of their life even. That really worried me. And then—here’s the cool thing, how this all comes together with the endocrine system: it was a paper that was published that showed there’s a hormone secreted by the pituitary that goes to the ovaries and testicles and tells them to make estrogen and testosterone. When the ovaries and testes are gone, that pituitary keeps making the hormone and making the hormone and making the hormone. What does that hormone do in the body? It binds to cells. And what happens when it binds to the cell membrane? It does two things. It induces inflammation. And it stimulates replication of the cells. So now this starts to make us understand why that endocrine mismanagement that is happening can lead to cancer. 

MD [9:35] That makes sense. Thanks for explaining that. I think, certainly, some of the arguments I’ve heard have been “spay/neuter dogs do tend to live longer.” Like you said, they’re going to go somehow. We expect that a lot of older pets are going to develop cancer, but the fact that they’re developing it younger obviously is very concerning. If people want to get a vasectomy or an ovary-sparing spay for their dog—like you mentioned in vet school, spay/neuter is kind of the mantra. Did you learn how to do a vasectomy in vet school or an ovary-sparing spay?

CZ [10:05] No. No, it wasn’t even on the radar at all. I still don’t think it’s on the radar in veterinary schools. Veterinary school curriculum is overwhelming already. I’m sure they would love to fit another year of education in so they can put all this information out, but they’re not going to do that. So, no, it isn’t available. But more and more people are doing it. I will tell any of you veterinarians out there, if you’re interested in knowing how to do a vasectomy, I have a very detailed video by a surgeon that describes how to do it. So I can provide that to veterinarians. There isn’t, to the best of my knowledge, any published data on ovary-sparing spay in which you take out the uterus but you leave the ovaries behind. It’s one of the reasons we’re setting up this survey. We want to know more about the effects of these surgeries in dogs. We can’t borrow from humans. And we can’t borrow from cats or horses or anything else because the reproductive cycles are very different in each species. So we’ve got to know about it in dogs. 

MD [11:05] Gotcha. So if someone wants to find a veterinarian who can perform one of these procedures… Or does the veterinarian have to find a mentor who is already doing these procedures to learn and where can people go if they are interested in one of these procedures for their dog? 

CZ [11:20] Currently, there’s no one place to look, but there’s a Facebook group called “OSS: Ovary-Sparing Spay and Vasectomy Information Group.” That’s on Facebook, and it’s got more than a thousand members. You can ask there for who has had the surgery done on their dog and whether they were satisfied and who they had do it. That’s one thing. Another place to find veterinarians who will do this is at Parsemus Foundation. If you look at that on Google, you’ll find that. They keep a list of veterinarians who do this surgery as well. Of course, we have social media, so you can always ask around and you’ll find someone. To be honest with you, whenever I speak to veterinary groups, I’m getting a lot of interest. There’s a lot of people who want to learn how to do it. 

MD [12:14] Cool, and I think we’re going to drop the link for Parsemus.org. So it is the Parsemus foundation. Their website is www.parsemus.org. If anyone’s looking for that directory… unfortunately, you may not find a veterinarian close to you, so if this is something you’re interested in, you might have to travel. You’ll kind of want to weigh the risks and benefits. A lot is just going to depend on whether there’s a veterinarian in your area, but like Dr. Zink mentioned, ask other dog owners, dog breeders, dog lovers. They may know someone who is not on that list who can help you out as well. So, reach out to your colleagues and fellow dog lovers. I had a question about what else the gonadal hormones do, and I think you addressed that already. So it’s really getting this idea across that it’s not just that the gonads affect reproduction; they do affect the whole body. They affect growth. We think they even affect behavior, obviously. You and Dr. James Serpell talked about this as well and done research on the effects of early spay/neuter on behavior. 

CZ [13:14] Very broad effects on the body.

MD [13:16] So, what made you think there needs to be research on this topic? How did we get from you recognizing that this was an alternative to hmm, we need research? 

CZ [13:29] I think that the situation regarding vasectomy is pretty straight-forward. We’ve done millions of vasectomies in men, and it’s a very simple surgical procedure. It’s just like done in five minutes in clinics for humans. So I think that’s pretty obvious. But the situation for female dogs is entirely different because we know that if intact bitches retain their uterus, they are at risk for a condition called pyometra, which is an infection of the uterus. It can be very severe and can even lead to death. The longer the dog has their uterus intact, the greater their risk. In fact, in some studies, the risk of a female dog that has its uterus is something like 20% of getting pyometra, so we definitely want to avoid that. Logically, of course, the idea would be then: Let’s remove the uterus and leave the ovaries in. There’s an interesting story here, because in the very early days of cervical cancer in women, when they had a pap smear, and they found abnormal cells, they actually took out both the uterus and the ovaries. Those women, unfortunately—their lifespan was shortened by 15 years.They experienced a lot of very negative effects: osteoporosis and other things. So in women, long term, they’ve just been removing the uterus. Of course, as I said, we can’t just apply what we know about humans to dogs. So when we realized there was just no information out there, and we would love to get rid of just that uterus and retain the ovaries, then together with Good Dog, we’re all thinking: Let’s put out a survey! Let’s get the information! There have been enough people out there now who have had this surgery. Let’s ask them what their experience was or has been, long-term. Not only for their dogs that are still alive but also dogs that have passed away. Personally, I probably know at least 50 people who have had the surgery, and I know there are hundreds and maybe thousands more that have. 

MD [15:32] So, yeah, this is bringing us to… Today is the big reveal of our survey!

CZ [15:38] Very exciting. 

MD [15:39] We’ve been fine-tuning this survey for many months now. Some of our breeders from our community volunteered to help us just do a pilot run last week, and it went smoothly, so we feel confident in launching. Just to give people a little bit of information about the survey and the research process: Data is close to my heart. I love doing research. I’m sure you feel the same way because you have been dedicated to doing research for many years. But this is a survey, so we’re asking basically anyone who has a dog, who has had a dog—

CZ [16:11] Any dog! Spayed! Neutered! Vasectomy! OSS! Intact! Any dog!

MD [16:17] Living or deceased. So you can answer these questions about a dog that passed as long as you know some basic information about their medical history. It’s a short survey, so it should take you about five minutes per dog, based on some of the feedback we’ve gotten. Maybe even a little less! The survey is confidential. Just so you know how we handle your data: you’re not asked for your personal name. We’re not going to release any identifying information related to an individual or even their dog. It’s really all about aggregating the data, so we’re trying to get as much data as possible, so we can say “Among vasectomy dogs, overall we saw X, Y, and Z.” Now, you are asked to enter your dog’s name to prevent duplication. Sometimes when people are filling out a survey with multiple dogs, they might accidentally fill out the information about the same dog. You can just enter initials. Or if you have a nickname for your dog? You don’t have to enter the registered name or anything that would identify you, unless you want to. We’re not asking for this information. We’re really just trying to make sure: if you have a dog named Jojo, you only answer one survey about Jojo. And then if you have another dog named Buddy, you answer a separate survey about Buddy. We do ask participants to just answer as accurately as you can regarding health and behavior. We really want to have good data with integrity, so that we can feel reasonably confident about what we’re finding. Of course, this is what we’d call a convenient sample, meaning we’re getting whoever is motivated to fill out the survey. If you are willing to fill out a survey about your dog, maybe you take better care of your dog than someone who is not going to take the time. We recognize this is not going to be a random sample of dog owners, but we’re also looking for very specific conditions related to their reproductive status, so we do want to reach as many people as possible. So if you have friends with dogs, friends that breed dogs, friends with dogs with vasectomies or ovary-sparing spays—please spread the word! Share the link. We’re not going to be able to prove that X causes Y, right? We’re not going to be able to say that keeping your dog intact causes this; spaying or neutering your dog causes that. We’re really looking for relationships, or what we call correlations. That’s part of the nature of the data we’re collecting. But it can help inform researchers as to where there are trends that require a closer, more careful look. This is really the first step in better understanding a phenomenon: survey as many dog owners as possible. We hope to finish data collection around the end of the year. Hopefully we’ll have a report back to all of you sometime early in the new year. It does take some time to clean up data and analyze it and make sure that everything is all cleaned up nicely. We’re definitely planning on sharing the results, depending on how things go. That could mean a scientific publication or it could mean just a summary that we report out to the world. We’ll kind of see what happens. You know, there’s always the possibility that we won’t find anything. You always have to accept that you’re not doing science to prove something. You’re doing science to find out what’s going on. Sometimes it supports your hypothesis, and sometimes it doesn’t. But I think, regardless, this is going to be a very valuable contribution. We really appreciate anyone taking the time to fill out the survey. I think we’re going to drop the link in the Facebook now, or soon, and we’ll be posting some ads in our Facebook group to some other sources later. Dr. Zink is going to share it with some of her communities online. The survey is live. If you have the link, you can fill it out. We’re going to start answering questions pretty soon, but Dr. Zink, do you want to add anything else about the survey methods or procedure?

CZ [19:39] I think, honestly, with the number of dogs that are spayed or neutered in North America, you should look at this as if you’re doing a huge service to all dogs everywhere. I can’t think of anything that you could spend 10 or 15 minutes on ( if you have that many dogs) or even 5 minutes for your one dog, that could have as far-reaching implications for the health of dogs. I don’t even think I’m exaggerating. I really don’t. This is the very first look at these procedures and being able to compare them to the traditionally spayed or neutered dogs, or dogs that have been left intact. This information has huge implications broadly for the health of our wonderful companions. I can’t stress enough what a gift it would be for you to fill it out. 

MD [20:29] It’s so true. We’ve just been operating under certain assumptions about what procedures are right or making judgements based on them, so this is a really good opportunity to expand our knowledge. We’ve got a couple of questions. Are you ready?

CZ [20:42] Absolutely.

MD [20:42] First question is just: Is there a recommended age restriction for having an OSS or a vasectomy? Should people wait until their dog is a certain age?

CZ [20:52] No, that’s the wonderful thing about it! It can be done at absolutely any age! For example, rescue organizations can be doing it on 8-week-old puppies that they have as a litter or any age. The same thing for OSS. Because the big age limitation happens if you remove the gonads, but of course that’s not happening in these two procedures, so that’s great news.

MD [21:15] We’ve got a question: Do people want to do OSS and vasectomies strictly to prevent pregnancy? Am I being judgy or naive to wonder why pregnancy is such a risk? There are management alternatives, after all. 

CZ [21:29] I so completely agree! If you’ve ever seen a dog and a bitch breed, it takes a long time. So I completely agree. The failure of the pet overpopulation problem is a failure of human management. I never vasectomized my male dogs because they’re never in a position to be near a bitch in heat, unless I wish that to happen. The issue for bitches is different, though, because for the female dogs, the longer they live with that uterus, the more they have that risk of pyometra. So there is that to consider as well.

MD [22:09] For, probably not your average dog owner, right? Dog owners are not always willing to manage things. They kind of want an easy solution. Certainly, if vasectomies or OSS turn out to be a safer alternative, then that’s worth considering for people that really just don’t have the desire or maybe ability to manage their dog’s breeding. It’s a human resistance kind of issue or willingness, I guess.

CZ [22:37] I do think there’s a higher level of management required for intact bitches, of course, than intact males because they do have heat cycles and that’s a time when you have to manage them and be extra careful. That’s another consideration.

MD [22:51] We’ve got a question about lengths of studies done on Labrador Retrievers that a breeder can share with their puppy families. I think we dropped in an article about early spay/neuter, and that has some references in it. Do you have anything to say specifically about Labradors? 

CZ [23:04] I guess the only thing I would say is that it’s clear that in the studies that have been done, early removal of the gonads does affect them and increases their risk of orthopedic conditions. It also increases their risk of cancers, if they’re spayed or neutered at any age, but not as much as Golden Retrievers. It’s clear that Labrador Retrievers are not as cancer-prone as Golden Retrievers. I think the real thing here when we talk about breeds is that we need to treat every single dog as an individual. We need to think about its breed. We need to think about its home life. We need to think about the issues. Does the person want to manage this or not? There are so many factors that are involved that we don’t want to treat this like mass veterinary medicine. If any of you are as old as me, you remember when every kid that got a sore throat got put on a conveyor belt and had a tonsillectomy. The surgeons made massive amounts of money on that. Only later did we realize that that is a really critical immune organ, and we were just cutting them out because they seemed inconvenient! We don’t want to do that. That was the ’50s. We want to be more thoughtful about the surgery that we perform.

MD [24:20] That’s a great point. When you do research, you are aggregating data and thinking about what Lynette and Benjamin Hart have done at UC–Davis. They’ve published a few papers on early spay/neuter and outcomes and looking at breeds, and you’re right: it’s like, okay, overall maybe Golden Retrievers had X, Y, or Z outcomes, but that doesn’t mean every single dog in that breed had the same outcome. It’s important to understand. 

CZ [24:48] Exactly. It’s a population study. 

MD [24:50] We do research. We’re looking at overall averages, but that can’t predict what will happen to your dog, and it doesn’t predict what will happen to any individual dog in that study. It shows you how that group of dogs did. So it’s really important to think about that as well. Okay, we’ve got more questions: Wondering about the best options of altering performance female after she retires from breeding? I don’t want to leave her intact and risk pyometra, but I have concerns about traditional spay removal hormones. But then OSS can have a stump pyometra, and they still go into season. But removal of ovaries and leaving the uterus is the same issue, albeit a smaller surgery. It still takes all the hormones. So basically this person is just trying to decide what is the best thing to do with her dog after her final litter. 

CZ [25:30] Okay, so I want to address one thing that she mentioned, and that is that dogs with an OSS can still get stump pyometra. I would say to that, that if the OSS surgery is done correctly, they absolutely will not get a stump pyometra. If it’s done sloppily, and the surgeon doesn’t take the entire uterus out, yes, that can happen. That’s why it’s so important to have this surgery done by an experienced veterinarian. That’s a really important fact. Really, the reason we’re doing it is to prevent pyometra. That’s only done by removing all of the uterus. It was a long question, but we should mention that dogs that have OSS can have mild heats. They have very little, if any discharge, but they’ll get a swollen vulva and they could have behavioral changes. But the biggest inconvenience of that, which I suppose would be the discharge etc., is a minor or non-issue. 

MD [26:30] Great, thank you. It was a long question; she has a lot of concerns. 

CZ [26:33] And I’m glad that she does! Because it’s really important to think about all sides of this question. And that’s what this survey is trying to address. 

MD [26:40] Exactly. Someone asked if, in a group situation (like a dog daycare), will neutered males attack intact males? So, should people be concerned about issues mixing intact and neutered dogs?

CZ [26:55] This is a strange but interesting situation. Neutered males do tend to aggress towards intact males. Yes, I think they’re jealous. They’ve lost their testicles. I’m only kidding! That is an actual issue, sadly enough. But doesn’t it kind of tell you that removing the testicles doesn’t lead to better behavior? That has been shown in a number of studies. But in a daycare situation, I would really hope that the people who are running the daycare are on top of this. If you were to take your dog, for example, to a dog park, you would be on top of this. I’m not a fan of dog parks, personally, but this would be something that you need to have in the back of your mind. Although, I’ll tell you: I’ve had unneutered males. I love the boys. So, I’ve had unneutered males all my life. Never been attacked by a neutered male. I think sometimes this is a little bit exaggerated. One instance gets known, and everybody gets worried. But, yeah, it’s part of managing our dogs. 

MD [27:59] It speaks to an interesting question: How does changing their hormonal profile change the dog–dog communication, right? Obviously, there’s something going on. 

CZ [28:09] They’re seeing something.

MD [28:10] Or smelling something. We sometimes have a hard time stepping outside our visual or whatever world we’re in. We don’t live in a very olfactory world. But, certainly, dogs do. It makes me wonder if there are some changes in how dogs understand what a dog is. Like, maybe removing the gonads removes some of their olfactory abilities or something. I don’t know! But it’s interesting that there would be that communication breakdown when they have different reproductive statuses. Okay, we are still getting questions: Any opportunity to manage pyometra, versus just using spay as an alternative?

CZ [28:45] Well, yes. The issue is: yes, there are different severities of pyometra, and not all of them result in death by any means. Many bitches can be treated for pyometra successfully. So it’s not only about absolutely having to spay or remove the uterus. But the problem with pyometra is sometimes it goes undetected. It can frequently go undetected until, really, it’s a very severe problem. Dogs are so good at hiding. They’re just like, “Oh, this is my life. I don’t feel good.” So, that’s the problem, that it might go undetected for a while—enough that it becomes really severe. But I do think, in some ways, veterinarians sometimes are so indoctrinated into spaying everything that they look at spaying the bitch as, “We’ll take care of that! We’ll get rid of everything.” I think, again, sometimes we have to maybe speak up and say, “I would like to try treating this, unless you could explain to me why we shouldn’t attempt that.” 

MD [29:50] Any early signs that people can be looking out for if they have an intact female? What would be a warning?

CZ [29:55] Fever, malaise, slowing down activity, just looking like a sick dog. That’s always worth checking, if you have an intact bitch. Take the temperature immediately. But some of them don’t have a fever. Get the dog to the veterinarian for a check. 

MD [30:15] Will an OSS result in a spay coat? You explain the spay coat and…

CZ [30:22] That’s a really interesting question. We don’t really know the answer to it, but we’re pretty sure that that spay coat is a result of not having the hormones that are produced by the ovaries, so I would think that with an OSS, you would not get spay coat. What is spay coat? It’s actually an overgrowth of the coat. Sometimes it’s kind of a uniform overgrowth, where the coat just gets big and oftentimes softer. But I actually have a neighbor who spayed her Golden Retriever, and the Golden Retriever has massive bulges of fluffy hair, just over the front legs, and over the back legs in the same place. She has to take a clipper and clip it every couple of weeks or the dog doesn’t even look like a Golden Retriever. So there’s variable levels of it. Most often, it’s just a really abundant, softer coat. 

MD [31:17] We’ve got a viewer who said: I ended up having an ovariectomy on my GSD at 20 months, hoping it would help her allergies. It did help the air-margin hair loss, but of course, not the allergies. Now I’m concerned that I did this too early, and I’m worried about future repercussions. So we do have some folks here who probably did get an early spay/neuter for their dogs. Can anything be done now? What should they be looking out for, as far as their dog’s health? 

CZ [31:44] First of all, I’m going to say that a study of 90,000 dogs—that’s a pretty big study!—showed that spaying and neutering made allergies worse. Whoever gave her that impression had incorrect information, which I know is frustrating, but I did want to say that. Here’s the thing: we know absolutely nothing about hormone replacement in dogs. We have no idea how you might approach it, or whether it can even be approached, or what you would give or how much you would give. So, honestly, there’s kind of no way of going back here. I think that this study may actually stimulate researchers to look into the question of hormone replacement therapy. I hope it might actually do that, so we can do something with these dogs that are already experiencing this. But at the current moment, we know absolutely nothing about that. And I wouldn’t suggest that we start using our dogs as an experiment and see what we can do. I don’t think it’s a good place to go. 

MD [32:49] I think I did see a case study published this year on a male dog, but obviously, a case study is not a body of research that supports doing something. More to come!

CZ [33:00] I think on a male dog, it’s much more clear. Because you’ve got testosterone. But, females, we’ve got that whole balance between progesterone and estrogen, and I think it’s just much more complex.

MD [33:11] Do intact females have a higher chance of mammary cancer? 

CZ [33:14] So that’s a good question, and I will tell you that… How can I explain this? There was a study done by [33:22] in 2012 that looked at all of the studies of mammary cancer in intact bitches. He showed that the studies that were done were biased and poorly organized. They were done, really, because people wanted to know if they could use dogs as a model for breast cancer in women. Really, it was just unsuccessful. But having said that, yes, intact bitches are at greater risk for mammary cancer. But here’s what it looked like in my study: First of all, mammary cancer, if caught early, by palpation (even if the cancer itself is malignant, histologically; it’s been studied and it’s been shown to be malignant) in general hasn’t gone anywhere. Also, at least in my study of Vizslas, what I did was I compared the incidence of mammary cancer (which I consider a much less fatal cancer) to the incidence of hemangiosarcoma, lymphoma, and other fatal cancers in the spayed dogs. There were approximately 10x more fatal cancers in spayed dogs than mammary cancers in intact dogs. So I feel very strongly that what we should be doing in intact females is exactly what we do in intact women, which is annual check-ups. We’re not spaying all the women because they might get breast cancer. I think that’s something that this study might lead people to ask that question: How can we manage that?

MD [35:00] Great! I’ve got a related mammary gland question, which is: What’s the effect on mammary gland infections? They didn’t specify, but I assume they mean—

CZ [35:08] Mastitis. Well, mastitis really only occurs in bitches that have had puppies. 

MD [35:15] I guess if they haven’t had puppies already. Okay. We’ve got a question about laparoscopic spays. What spay is done laparoscopically? 

CZ [35:27] Well, the most common spay or surgery that’s done laparoscopically is removal of the ovaries only, which in my opinion, has the equivalent outcome to removal of both the ovaries and uterus. Really, it’s just like a traditional spay but involves less intervention. The hormones are gone. At least currently, we can’t do a laparoscopic OSS. You have to go in and look and see where the cervix and uterus are and make sure you get all the uterus out. 

MD [36:03] Does pyometra happen only during heat, or could it happen at any time?

CZ [36:06] I believe it’s only as a consequence of being in heat. Happens after being in heat. 

MD [36:13] Great! We’ve got a question about zeutering. 

CZ [36:17] I’ve got two points to make on that. 

MD [36:19] Can you first explain what zeutering is? 

CZ [36:22] That’s the injection of, in this case I think it’s a zinc-related compound, into the testicles to stop a dog’s reproductive ability. The problem with that is that you also kill off the cells that produce the testosterone, so you may as well just take the testicles out. You end up with 25-40% of the normal level of testosterone, so to that extent, you’re also going to end up with a greater risk of problems associated with removing the testicles. The other thing I just want to say is: If you talk to the manufacturer, they will tell you it’s painful. If you think about injecting 1cc of even a sterile saline into a testicle and ask some men about what they think that would feel like… It’s painful. It’s quite painful. I don’t recommend it for those two reasons.

MD [37:10] It made me squirm a little bit inside, so… Okay, we’ve got another spay coat question: Does spay coat happen every dog gets fixed? Since my dam got spayed, her coat has been softer and fuller. Do all dogs get spay coat? 

CZ [37:27] Most. But it’s particularly noticeable in dogs that have double coats. For example, a dog like a Pharaoh Hound, you might not notice it in very much because they just have a short coat anyway. Maybe it’ll get a little thicker and a little softer, but it’s not as noticeable. But in dogs with double coats, like Shelties and Golden Retrievers and Labrador Retrievers and other dogs with abundant coats, it can become quite noticeable. 

MD [37:50] I feel that way about my own hair sometimes. Just a reminder: I believe we posted the link to the survey, and we’ll be sharing it online in multiple venues over the next few days. We’re really excited to have your participation, and we’re excited to learn more. Because they’re the least common procedures, if you know anyone who has a dog who’s had a vasectomy or OSS, please encourage them to participate! Just because I think that’s going to be the hardest for us to recruit a large number of. Obviously we know we’ve got a lot of intact dogs amongst our breeder community, and we know a lot of dogs out there—what percent of dogs do you think are spayed and neutered? 

CZ [38:32] In the pet population, it has to be well over 90%. 

MD [38:35] Wow, okay. 

CZ [38:36] It’s great that this is going out to Good Dog because we also want lots of intact dogs, too. 

MD [38:41] Yeah, but it also speaks to if some of the concerns about early spay/neuter in particular are these health consequences and 90% are…

CZ [38:48] Yeah, how massively that affects the population of dogs. 

MD [38:52] We’ve got people bringing in some more questions: Is there any information about the effect on behavior of neutering a 2.5-year-old Golden Retriever? Probably the study that you did with James Serpell touched on behavior, I’m guessing?

CZ [39:08] I’m not sure if the Harts’ study addressed that as well. Let me tell you the results of my Vizsla study. It’s another sporting breed. It’s not exactly Golden Retrievers, but it’s your average sporting breed. I’ll tell you what I learned there. There I looked specifically at dogs that were spayed at 6 months or earlier, between 7-12 months or after 12 months, and behavior. We ruled out all of the dogs that were neutered because of an already-existing behavior problem, so they weren’t in that part of the study. What we found was it didn’t matter what age the dog was spayed or neutered at. They were more likely to develop a behavior problem. Not only that! They were more likely to develop at an earlier age. That’s worrisome. And then another study that I did looked at over 15,000 dogs using Dr. Serpell’s C-BARQ behavioral questionnaire, which is very well-validated. That looked just at aggression. It looked at aggression towards other dogs, aggression towards family members, and aggression towards strangers. We looked at dogs that were spayed or neutered at 6 months or younger, 7-12 months, 12-18 months, or after 18 months of age or left intact. We showed that, contrary to popular opinion, spaying and neutering didn’t make a dog less aggressive. But dogs that were spayed or neutered between 7-12 months of age were more aggressive to strangers. 

MD [40:36] We’re getting some questions more in the philosophical attitudes about spay/neuter. What about shelters who must spay and neuter early? How do we address that situation? 

CZ [40:47] I’m going to risk being a little bit of an outsider on this opinion here. I would like to say that I think that we need to be very, very careful about our understanding of what this so-called pet overpopulation problem is in this country. If we really have a pet overpopulation problem in this country, why in 2012—according to the CDC—why did we bring 12,000 dogs from the streets of Taiwan to populate the shelters in the Pacific Northwest? Why are we going to Mexico to get dogs? Why are we going to the Caribbean to get dogs? Why did we bring 600 Golden Retrievers from Turkey? Etc. This is happening over and over again. Dogs being brought from Korea. Why do we have a pet overpopulation problem if that’s what we’re doing? We have to ask ourselves. It’s a lot more nuanced than we think. While I recognize that there are areas in the country where there are pet overpopulation problems, this is not a uniform problem across the country. I do feel we should take care of it within our own borders first and not be looking to save every dog in the entire world. Let’s look at it within our own borders and shift dogs from where there are overpopulation problems to where the shelters are empty, which is basically the Northeast and the Northwest. Let’s also understand that sometimes the people who run shelters are making their livelihood from finding dogs for dogs. If there are no dogs in their area, how are they going to make their livelihood? Sometimes it’s an issue of retail rescue, not good-hearted rescue. I recognize there are wonderfully good-hearted people who are really trying to find homes for dogs. But what we lack is data. We lack the knowledge of exactly how many dogs there are that need homes. The other thing I’d like to bring up as well is that not every dog in every shelter deserves to be alive. Some of them are just not going to make good citizens. We need to be better at selecting those ones that are. 

MD [43:01] I think that’s a hard thing to discuss or talk about. It makes a lot of people uncomfortable, but it’s certainly important to consider. That brings up a few questions, which is one person mentioned their vet completely resists not neutering. Will there be information going to vets to raise their consciousness about this topic, and also just about the cultural differences? In some countries, they really don’t practice standard spay and neuter them all. It really seems to be more of just an American thing. Would you agree?

CZ [43:28] Well, I would like to say that in some of the most educated countries in the world, like Scandinavia, it’s illegal to spay or neuter because it’s considered an unnecessary surgery unless there’s a medical reason. That speaks very much to their ability to manage their dogs, because they don’t have an overpopulation problem. It’s a human problem in the United States. We need to also address it on that front as well, by education, peer pressure, and other factors. 

MD [43:53] We’ve got someone that wants to confirm that it’s okay to perform a vasectomy or OSS on an 8-week-old puppy.

CZ [44:00] Yes.

MD [44:00] Thank you. If someone wants to fix a dog with a traditional spay/neuter, should they get X-rays to see if their dog’s growth plates are closed first? 

CZ [44:11] That would be helpful. However, that won’t mitigate the fact that their dog is going to be at increased risk for behavior problems and cancer, particularly in the larger breeds. 

MD [44:24] Someone wants to know if spaying a breeding female right after her last whelping is the best practice. I guess, assuming that they are going to spay her. 

CZ [44:32] I probably would wait until at least a month until after the puppies have been weaned. Maybe two months. Probably a month after the puppies have gone home. 

MD [44:40] Great! We’ve got a question: With the possible mild heat mentioned earlier, do females with OSS still have the same potential for blowing coat or false pregnancy as they do in a traditional heat? 

CZ [44:53] That’s a question we don’t know the answer to, effectively. It’s one of the things we want to know about. I would think that because that’s an estrogen/progesterone-related issue, that they probably would still blow coat. But not like the way they blow coat after having puppies, certainly. It’s kind of a question mark. Not sure.

MD [45:14] We’ve got a question that we can answer very easily. Someone wants to know if we want survey respondents from only the United States, only North America, or from the whole world? Where should they share the survey?

CZ [45:24] The whole world! 

MD [45:27] Everywhere. Share it with everyone you know who might be interested in participating, for sure. I think on that note, we will wrap up. I just want to thank you so much for, first of all, working on this with us. We’re so excited at Good Dog to be participating in research. We hope this will just be the first of many research projects. We are just more than honored to have you as one of our advisors and to be collaborating with you on this project. Thank you, Dr. Zink. And thank you, everybody here, for hanging out with us and asking so many amazing questions and being so engaged. This was really fun. 

CZ [46:00] Remember, everybody, you have the opportunity here to change the dog world!! To change dogs’ lives. It’s exciting. 

JS [46:09] Yeah, we’re so excited to work with everybody. This is a great opportunity for us, and we really hope to answer some really important outstanding questions and improve the lives of our dogs. Thank you, everybody!