...or you could zeuter the dog, instead

The dog was on his back, sedated on a table. I was not wearing a surgical cap or a sterile gown. I held the first testicle between two fingers, pushed the needle in, and injected a little less than a milliliter of a mixture of zinc gluconate and L-arginine. Then the second testicle. And now the dog was non-surgically castrated. In a few weeks, once he was rid of the sperm he had already made, he would be sterile for the rest of his life.

This product, Zeuterin, is newly released in the US market, just starting to make its way into veterinary clinics. I was part of a one-day training at a low cost spay/neuter clinic which has partnered with the company as an early adopter. On the one hand: if we can avoid doing surgery on dogs, why wouldn't we? Isn't an injection better than cutting? On the other hand: if you have to sedate the dog for the procedure anyways, and surgical castration is so very quick and simple, what's the benefit of zeutering rather than surgically neutering them? And is the benefit to the dog (healthier) or to the human (faster and/or cheaper)?

I'm considering a few different populations of dogs: owned dogs being brought to a clinic, shelter dogs being altered on site, and owned dogs being altered on an outpatient basis. The answers to the above questions will differ for each population.

• Sedation versus anesthesia: Surgical castration of a dog requires full anesthesia. Zeutering requires only sedation, and in some calm dogs can be done without even that. A dog will recover more quickly from sedation than from anesthesia, so he'll be able to go home earlier in the day. (Important in a clinic and for outpatients; not important for most shelters.)
  
• Time: You'd think that an injection would be faster than surgery, but it isn't clear that this is so. A trained high volume surgeon will perform a castration (a very simple surgery) in just a minute or two. The injection has to be given slowly and the needle has to be positioned precisely. The time difference may not be significant.
  
• Cost: Zeuterin is expensive! It costs $10-25 to neuter a dog with this product, depending on the size of the dog. I don't think anyone really knows how this compares to surgical castration, which doesn't have clear costs per animal. How much is your surgical suite costing you, and how valuable is it to keep a dog out of it? How much does it cost to sterilize a pack of surgical instruments? For shelters where every penny is counted, the cost of the product will matter more than in a veterinary clinic where an owner may not mind a difference of $10 one way or the other.
  
• Using technicians: Technicians can't perform surgery. That requires a veterinarian. But a technician can give an injection. The spay/neuter clinic where I learned to zeuter are currently only allowing vets to zeuter, but they expect to start using technicians in this role as they become more comfortable with the procedure. Saving the veterinarian's time is a big bonus. Vets are expensive!
  
• Testosterone reduction: Surgically neutering a male dog reduces his testosterone level by 100%. Zeutering him reduces it by 50%. Which is better? Hard to say! We don't really know yet whether zeutering will reduce unwanted behaviors (roaming, peeing on things) the way neutering sometimes does. (But we tell people that really training is better for that sort of thing anyway.) And is it healthier for a dog to have all of its testosterone, or only half? Testosterone is a steroid which affects metabolism and various physiologic process in many ways. I'm guessing that it does some good things for dogs and some bad things, and only time and a lot of research will tell whether it's better to have 50% or 0% of normal levels.
  
• Aesthetics: Zeutered dogs still have their testicles, although atrophied and therefore somewhat smaller in size. Good or bad? Opinions will differ on that one.
  
• Complications: Surgical complications can include anesthetic death and bleeding, but complication rates for this simple surgery in healthy dogs are very low. Complications with zeutering include the development of ulcerations or even necrosis of the scrotum. These complications are also expected to be low when the procedure is done correctly, but again, it's too soon to know exactly how that will shake out.

So is there a place for zeutering in veterinary medicine? I think there is, but it's not clear yet exactly what it will be. I'm not convinced that that place is in a shelter (though some shelter vets disagree with me). I'm also not convinced it's in a general practice veterinary clinic for the average owner, although I think some owners will prefer Zeuterin both for avoiding general anesthesia and for maintaining a higher testosterone level, and of course for keeping the dog's balls. The place I really see this product is for performing neutering outside of the veterinary clinic, for example, in low income areas of the US where the population has difficulty getting their animals to a veterinary clinic, either for lack of transportation or for lack of enough committment to follow through with an appointment for surgery. In other countries, trap-neuter-release programs may also find a great benefit to being able to do this procedure in the field.

(Posted by a bleary DZ at the fabulous but overwhelming ScienceOnline 2013 unconference.)

Diary of a shelter medicine veterinary intern: late fall

I seem to have spent two months with no time to blog. What in the world was I doing?

The last you heard from me, dear readers, I was in the first week of our month-long shelter consult. The first week we digested a lot (a LOT) of data from the shelter. The second week we wrote up what we thought about that data. How many dogs did this shelter take in over the last few years? Cats? Are there changes in intake? How many of each species were euthanized? Why? What is the average length of stay for each species? Are pit bull type dogs treated differently? Etc.

The week after that, we were on site, crawling all over that poor shelter. That was a very busy week; in the evenings we were scrambling to write up everything we had seen and photographed during the day. On the last night of the consult, we generated our exit report, which was an overview of our findings. What did we think were this shelter’s greatest strengths? Its greatest challenges? What did we think they should address first? How? What was our five year plan for them?

The week after that, we were back on campus, writing, writing, writing. The complete consult report is traditionally quite a long document; in previous years it has been hundreds of pages long. The shelter medicine residents (the veterinarians who are specializing in shelter medicine) worked on the report for another week after that, but we interns were released after just one writing week.

After that, I spent two weeks at a truly lovely limited admission, adoption guarantee shelter about an hour and a half from home. I shadowed the shelter vet some of the time, and worked on my own some of the time. I did a lot of physical exams and surgeries! I also helped one day to select animals from the local municipal shelter (lots more animals, lots more euthanasias) for transfer to the adoption guarantee shelter. Our truck was almost full of animals when shelter staff pointed out an ancient, arthritic collie mix and asked if we might consider taking her. I argued against it, saying she was too old and decrepit to be adoptable. But in the end we felt sorry for her and took her (another dog had to ride on my lap on the way home to make room). Then I felt too bad for her to put her in the shelter kennels — her arthritis was so bad and she seemed so depressed. So I took her back to my room for the night. And the next night. And home over the weekend. And hung on to her my second week in the shelter. I officially adopted her on the last day. Her name is Rosie.

In mid November, I spent two weeks on campus, working with veterinary students as they learned how to spay and neuter animals. I am getting more and more confident in my own spay/neuter skills, but teaching still feels scary. Will I be able to tell ahead of time before someone does something wrong? I also got to amputate a badly broken leg off of a kitten. My first amputation! Terrifying. There are big arteries in there.

After Thanksgiving, I was on campus again for our shelter behavior course. This was a blast. A lot of reading about behavior (one of my favorite things to do), and a surprising amount of hands on work. We learned about different temperament tests for dogs and tried them out, both on shelter dogs and on our own dogs. We visited some different shelters in the area and talked about how they handled their dogs, and at the end of the two weeks we spent two days at one shelter, getting hands-on helping some of their dogs: setting up play groups, putting up cage barriers for those dogs who were over-stimulated by their surroundings, hanging treat buckets, etc.

Now I am in the hospital on the dermatology service. Skin problems are really, really common in shelter animals, particularly in the South. Flea allergies! Pollen allergies! Allergies allergies allergies! Also mites.

And that brings me to today. I finish up my dermatology rotation next week and head on to another week in the emergency room. And that is what I have been up to. I have been quiet, but I have not forgotten you guys.

Will we ever be able to measure cortisol in real time?

In my Copious Free Time (CFT), I sometimes like to try to figure out how close we are to implementing some of the crazy technology I’d love to use in research. I want to learn more about the canid stress response, as a way of learning about canid domestication (domesticated animals have blunted stress responses, and this may be part of why they are so accepting of novelty and so easy to socialize). The hormone that most people use to study the stress response is cortisol.

I have written in the past about some of the many problems with studying cortisol. Two of those problems are

• Getting hold of cortisol (from blood or even saliva) without increasing the animal’s stress and therefore invalidating your study, and
• Measuring cortisol frequently enough to actually be able to track its very rapid changes in the bloodstream (changes on the order of minutes, continuing to occur and be important over the course of hours).

What we really need, obviously, is a Star Trek-style tricorder that we can point at an animal and ask “what is this animal’s blood cortisol level just now? And how about now?” So recently I was wondering how close we were to this technology.

I asked a friend who works in research imaging. She obligingly sent me a review paper to read, about studying dopamine levels in humans using PET. The problem this paper addresses is getting at the dopamine levels in the brain without having to slice open the skull (something we definitely don’t like to do in humans — and although we might be willing to do it in rats or mice, it is going to be hard to retest the same animal later to see how its dopamine levels have changed, seeing as how a common side effect of skull sliceage is death). This is a pretty cool technology. It goes something like this:

• Inject the individual with a radiotracer which is attached to dopamine agonist or antagonist. The agonist or antagonist will attach to dopamine receptors, and the radiotracer will allow us to use PET to monitor how much of it is attached in the part of the brain that we care about.
• Monitor the changes in the radiotracer in the region of interest. As dopamine levels in that region increase, the unlabelled dopamine will bump more and more labelled agonist or antagonist off of the receptors, which will mean there will be less radiotracer in the region. Less tracer implies more actual dopamine. Do math.

Egerton A., Mehta M.A., Montgomery A.J., Lappin J.M., Howes O.D., Reeves S.J., Cunningham V.J. & Grasby P.M. (2009). The dopaminergic basis of human behaviors: A review of molecular imaging studies, Neuroscience & Biobehavioral Reviews, 33 (7) 1109-1132. DOI: 10.1016/j.neubiorev.2009.05.005

You could use something similar to monitor cortisol binding in the brains of dogs. That would be very interesting, actually, but the studies I tend to envision are more concerned with cortisol amounts that are released from the adrenals. We are actually in a better position here with cortisol, compared to the suckers studying dopamine in the brain: dopamine is released in the brain and stays in the brain, so you never get a chance to see it in the bloodstream. The bloodstream is actually easier to get at than the brain, obviously.

Conversely, cortisol comes from the adrenal glands (way down near the kidneys, far from the brain). The brain sends a signal to the adrenals via very long nerves, and then the adrenals release more or less cortisol, for a longer or shorter period of time. It’s the “more” or “less”, “longer” or “shorter” that are interesting. I actually don’t know enough about where cortisol binds to say if using a radiotracer-labelled cortisol agonist or antagonist, to sit on binding sites, would be interesting, but I suspect this is not the right direction for this technology. Cortisol binds in organs all over the body and affects a lot of processes. Unlike with dopamine, where researchers are interested in very specific (hence small) brain areas, we would want to scan the whole body for cortisol binding.

The radiotracer idea is interesting, though. Maybe we could attach a radiotracer to one of the precursors of cortisol, like cholesterol? We would inject labelled cholesterol. The adrenals would take it up and convert it to cortisol. Then when they released cortisol, we could see the label spreading across the body. No need to measure binding. We could in fact just scan one part of the body where there is a lot of blood — a vein coming out of the adrenals? — to watch cortisol levels rise and fall. The downside: the use of PET to monitor the changes in the radiotracer label. PET is expensive and it requires the subject to hold... perfectly... still. Something dogs are not very good at doing.

What I really wanted, I decided, was something that works sort of the way a pulse oximeter works. Pulse oxes are little devices that you hook up to an animal while it is under anesthesia to monitor their blood oxygenation (you know, to tell if they are dying or not, something which ironically is often easier to tell just by looking at the animal, but we use the things anyways). These devices work by shining a light through an area of non-pigmented skin (such as the tongue, an unpigmented paw pad, or if all else fails, a vulva) and measuring how much hemoglobin (hence oxygen) is in the blood based on color. Could some such device measure amounts of tracer label?

I was letting these ideas percolate and considering how I might write them up for you, dear readers, when I completely by chance came across the following announcement: Sano Intelligence is working on a wearable patch which will continuously monitor blood chemistry.

A wearable patch! That’s actually a much better solution to this problem. It operates wirelessly, so you slap it on (at a cost of $1-2 per patch for materials, though much more in the end to the company to pay for development costs, I imagine) and then remotely monitor changes in blood sugar, electrolytes, and — cortisol? Of course the company does not mention cortisol as one of the substances the patch would monitor. I wonder if there is any reason it couldn’t be included, though. It would help if I had any idea how this patch worked. The company asserts that it’s non-invasive and does not hurt to apply. So how does it get at the substances in the bloodstream? Apparently the company isn’t saying until the patch is released.

So now I wait. If any of you out there in internet land know more, or have thoughts on how this might work, let me know!

When the patient is a shelter: week one

The next question I get after “what do you do?” is always “what’s shelter medicine?” I have been playing around with different ways to sum up a complicated veterinary specialty in a few sentences, suitable for cocktail party conversation. (No, I do not actually go to cocktail parties.) Recently I found an answer I liked: shelter medicine is where the patient is an animal shelter, not an animal.

For the next four weeks, my shelter medicine program will be working on a consultation with a particular animal shelter. This week, we are analyzing data from the shelter, which is a large municipal animal care and control facility in the South. As such, it will be open admission (take in almost any animal offered to it) and therefore likely to perform euthanasia of potentially healthy animals to free up space for more animals, rather than solely for behavioral or medical purposes.

Step one: analyze what this shelter takes in. I have received spreadsheets of data from the last five years. I will be building data tables to tell us how many animals of each species it accepted (we’re only looking at cats and dogs); how many animals of each age category it accepted (kitten/puppy, adult, and the always dreaded “unknown,” of which there are more than you would expect at most shelters even though it isn’t hard to tell if an animal is an adult or not); why the animals came to it (surrendered by owner, stray, confiscation, returned by an adopter, return from foster care, other). This will help us understand where most animals in the shelter have come from, which will be key data in making recommendations to the shelter about how to work to reduce their intake numbers.

One of the residents in my program is simultaneously looking at what happens to the animals who are in the shelter, by age and species: euthanized? Died in the shelter? Adopted out or transferred to a rescue (“live release”)? This will help us make recommendations about how to increase live release. For example, which kinds of animals are most at risk of euthanasia: feral cats? (Does the shelter have a trap-neuter-return program?) Adoptable puppies? (Do they have a program to transfer to other groups which might have more resources to put towards finding homes?) Adoptable kittens? (There are always too many kittens!) Sick animals? (It may be acceptable to euthanize sick animals, but why did the animal become sick? Does the shelter have a problem with communicable disease?) And, of course, we will look at how many animals died in the shelter. (That is the worst outcome. That should rarely happen. If it happens too often, it is a huge red flag.)

So wish me luck with all my spreadsheets. Luckily, I used to be a computer programmer. I may call on some old skills to help me out this week.

Cuteness interlude

You all like photos of foster kittens, right?

You can only see four of them there. For some reason one is always off doing something else (always a different kitten).

They are probably around three weeks old. They had not quite gotten the concept of solid food yet and were not eating well in the shelter where I was working last week, and were underweight. One of them had a bad upper respiratory infection, which was manifesting as bad conjunctivitis (inflammation around her eyes). She looks much better today after meds and someone willing to mix up juuuust the right concoction of milk replacer plus canned food.

 

 

It’s hard to tell in this photo, but her eyes are still pretty red. I’m not worried about her any more, though. She will do fine.

The Feral Freedom program: leave outdoor cats where they are!

Even in parts of the country in which the dog overpopulation problem is mostly under control, the cat overpopulation problem is still rampant. Cats entering shelters often have a less than 50% chance of adoption, down to 10% or less in many communities. Certainly, unfriendly feral cats coming in to shelters have a miniscule chance of adoption, so small that most shelters euthanize them rather than trying to find them a barn home.

On the other hand, cats living outdoors often do very well for themselves. Contrary to the popular assumption that the life of an outdoor cat is nasty, brutish, and short, most of the cats coming through trap-neuter-return (TNR) programs are healthy. They may not live as long as indoor cats, but they are not miserable. To some people, the idea of euthanizing a cat rather than run the risk of its being hit by a car in a year seems silly or even a little mean.

The city of Jacksonville, Florida, recognized that the choice for outdoor cats, feral or not, was either to be spayed/neutered and returned to their territory, or euthanized. That was it. Certainly feral cats stood no chance of adoption, and the influx of friendly cats was so great that their chances weren’t much better. That realization was the seed of Jacksonville’s Feral Freedom program. This program facilitates the sterilization, vaccination, and return of all healthy outdoor cats that are presented to the shelter. These cats come from the surrender of “stray” cats and from active trapping. Rather than become shelter inhabitants, they are returned to the location where they were originally trapped or picked up.

Does it cost a lot? Because the city was holding all cats for five days in case an owner came to reclaim them, and paying for euthanasia and disposal of the body, the program costs the same as the previous policy, or a little less.

Do owners fail to find actual stray cats when they are not held in a shelter? Research has shown that stray cats are less likely to be reunited with their owners in shelters than if they are left outside to find their own way home. Many owners do not expect to see their outdoor cats daily, and may not start looking for a missing cat until after it has already been euthanized in a shelter.

Are outdoor cats nuisances? Some certainly can be, although sterilization does reduce nuisance behavior, and vaccination reduces disease. (Cats are much more likely to get sick in a shelter than outdoors.) Feral Freedom provides assistance to people with complaints about individual cats. They will trap, sterilize/vaccinate, and return the cat, and then suggest that people who want it off their property try methods like motion-sensitive sprinklers. (And hilarity ensues.)

Do the good citizens of Jacksonville approve of this program? Jacksonville initially implemented the program on the sly without a lot of publicity, but did publicize it once it had proven to reduce cat euthanasia rates in shelters. The city receives complaints about individual cats, but rarely about the program as a whole. Most people, when they understand that the cat’s choice is euthanasia or return, accept that putting the cat in a shelter is not a humane option. (Some people do disagree. That will be true of almost any public policy, except maybe the one where every new baby gets a chocolate eclair.) But cats will not be relocated, even problem cats. Aside from the question of how well a cat will do when dropped down into a new territory, there is nowhere for them to go. There are no places that want more outdoor cats.

And, of course, the ethical questions. Isn’t it the job of a shelter to provide care for homeless animals? Of course it is. But if the shelter does not have the resources to provide for all of them, does it become the job of the shelter to kill them when they are not otherwise suffering? And aren’t cats better off in a good home? Of course they are. But if there is no good home available (or even bad one), are they better off dead?

I certainly recognize that this approach to cat overpopulation is a controversial one and that many will disagree with it. (If there is interest, I may blog later about the questions of communicable disease in outdoor cats, or predation of wildlife by outdoor cats.) But I think we have reached the point in dealing with the pet overpopulation problem where revolutionary ideas are worth trying, because we have tried almost everything that is non-revolutionary. Don’t get me wrong: euthanasia of healthy domesticated animals has certainly decreased in the past decades. But there is still a long way to go. As one of my faculty advisors said to me recently, “It’s an exciting time in shelter medicine. Everything’s on the table.”

For more information:

• Feral Freedom Guide from Best Friends
• Feline Shelter Intake Reduction Program FAQs (PDF)
• TNR Fact Sheets from Vox Felina
• Feral Freedom comes to DeKalb country, Georgia

Hey, want to get rid of those ovaries, cheap?

A few months ago I was watching a general practice veterinarian perform a dog spay. And I was surprised by how slow he was. He seemed hesitant, not confident in his technique, and he took a good forty minutes to finish the surgery. He commented to me, “I only do about one spay a month. Most of the animals we see these days were spayed before they left the animal shelter.” This made me wonder: if I had a dog that I wanted to have spayed, where would I take her? To someone who only performed this complicated surgery once a month? Or would I actually rather have her spayed at a shelter, by someone who does multiple surgeries a day, even though she is less likely to have high quality anesthesia management and individual attention there?

The answer to the question of how to offer high quality, high volume spay and neuter services to the general public is veterinary clinics focusing entirely on spay and neuter, and not offering general health care. One model clinic of this type is Humane Alliance in Asheville, NC. This sucessful non-profit clinic was founded in 1994, before much of the rest of the shelter community had woken up to the fact that high volume spay/neuter is an important component of reducing pet overpopulation. Today, 25% of the animals they surgerize are privately owned and come in on appointment. The other 75% come from shelters, rescues, and feral cat trap-neuter-return operations within a sixty mile radius of the clinic (transportation is provided by the clinic). On any given day they may have 100-125 animals in the building receiving surgery.

The Humane Alliance model was so successful that other clinics began coming to them for help. In 2005, Humane Alliance began accepting applications for National Spay/Neuter Response Team (NSNRT) members, member clinics designed on the Humane Alliance high volume model. They define “high volume” as at least 5,000 surgeries per year, though they note that most clinics perform at least 7,000. With a profit margin of about $2-3/surgery, this nets the clinics a profit of about $10,000/year, which is enough to keep them afloat. Today, there are 110 NSNRT clinics, and five more are expected to be operational before the end of the year. Humane Alliance helps the clinics every step of the way, from the design of their business plan, to the list of medications to have on hand on opening day, to sending staff members out to work on site at the new clinic for the first week.

Do these clinics provide spay/neuter surgery in the style of shelter surgeons? In some ways, yes, because their protocols are very much oriented to high volume, with the expectation that one surgeon will handle up to dozens of animals a day. But the quality of the care is extremely high. Arguably the most dangerous part of surgery is going under general anesthesia, and these clinics do not skimp on their management of this aspect of surgery, down to the details of keeping the animals extra warm on a heating blanket while they wake up.

I like this vision of the future: veterinarians who are specialists in spay/neuter surgery, working in clinics that are focused on this one complicated procedure, providing services of higher quality and for lower cost. Making spay/neuter more affordable and more accessible can only be a good thing for pet overpopulation. Unfortunately, the reaction of many general practice veterinarians is not so enthusiastic. Because these types of clinics charge much less for surgeries (often well under $100), veterinarians at full service clinics often fear that their clients will be stolen from them by clinics offering less expensive services.

Is it a realistic fear? I don’t think so. Full service veterinarians offer full service: wellness care, and management of sick animals. Spay/neuter clinics offer a one-time interaction with the client. Full service veterinarians may indeed lose spay/neuter business, but I contend that those services don’t comprise a large part of their income to begin with. The rest of their services aren’t threatened.

I think these clinics are going to continue to expand, and become an accepted part of the way veterinary medicine is practiced. The old adage “good, cheap, fast: pick two” is disproven here. This is the place I would take a beloved animal to have surgery.