Spaying big things, spaying small things

You would think that spaying something big would be a lot easier than spaying something small. With something big, you can visualize everything more easily, right? It turns out to be the exact opposite, actually. The smallest thing I've spayed is a two pound kitten, and oh boy is that uterus easy to find and manage. The biggest thing I have spayed is a hundred something pound Great Dane, and wow was that uterus deep in a deep abdomen and so covered in fat that it was hard to see where it stopped and the ovaries started. Big things bleed a lot; big things have ligaments that are really hard to break down (as in, you will get out of breath); big things have all kinds of extra fat and tissue and such that get in the way. Little kittens (and cats and puppies) have pristine little uteruses that pop right out at you.

This is something that vet schools don't make clear enough, in my opinion -- at least, not the one I went to and not the one that I work at now. I was supervising some beginning surgeons recently. Day Two was amusing: everyone who had spayed a cat the day before was spaying a dog, and they were all complaining about how hard it was. Everyone who had spayed a dog the day before was spaying a cat, and they were saying things like "I'm so much better at this than I thought I was!" No, you're just spaying a much smaller animal.

Given all of that, it bewilders me that vet schools seem to tend to start students off on dog spays. Why not cat spays? They are so much easier. Why start a beginning student on the hardest possible case? This is yet another brick in the wall that stands between me and understanding how veterinary education makes any sense at all.

Community-based veterinary public health

My public health class in veterinary school was a revelation to me: veterinarians could prevent problems from happening in the first place rather than playing catch-up and trying to fix things after they are broken. I still remember sitting in the class and thinking “This is what I want to do.”

When it was first born as a profession, human public health was about infectious disease: preventing cholera by cleaning up the water supply, preventing tuberculosis by vaccination. But in recent decades, public health has come to be more and more about lifestyle changes: improving nutritional choices, encouraging increased exercise. I’m obsessed with animal welfare and behavior, so I love the idea of a veterinary public health specialty focused on improving what we might call “lifestyle problems” in animals. Here’s my list of what some companion animal lifestyle problems might be:

• Obesity
• Behavior problems, such as separation anxiety or aggression
• Dogs on chains in yards
• Dog fighting rings
• High rates of surrender of animals to the local shelter
• Low rates of adoption from the local shelter
• Lack of veterinary care, either because community members cannot afford it, or because it is simply not available

Basically, I figured, veterinarians would work to improve animal husbandry (the way animals are kept and fed). Education of animal owners and handlers! Projects focused on making it easier for owners to get regular veterinary care, take their dogs for more walks, or stop chaining their animals in yards! Let’s go!

But check out the articles in the Journal of Preventive Veterinary Medicine: articles about disease, articles about food animals, articles about disease in food animals. Any articles about disease in dogs are most likely to get published if they are about diseases that threaten humans. Articles about lifetyle problems in pets are few and far between, and I have yet to find an article about an initiative proactively addressing one of these problems. Of course preventing infectious disease is important, but isn’t changing poor husbandry important too? Is veterinary public health actually decades behind human public health in its reluctance to focus on lifestyle diseases?

I asked myself what questions a public health veterinarian might ask about a particular community. Smaller communities are probably more manageable than large communities, but in theory a community could range from a neighborhood to a city to a country. Of course, remember that I am not a public health specialist — I don't have a Masters in public health and I don’t work in public health — so please take my ideas with a grain of salt. But here goes.

1. What are the most significant problems of animals in the chosen community?
2. Why are these problems happening? What does the community need to do in order to solve the problems, and does it have the resources it needs in order to make those changes?
3. How can we work with the community, providing it support in bringing about change? How can we provide the community a path to self-sustaining change, rather than coming in from the outside and mandating change?

One such outreach project, arguably, is HSUS’s Pets for Life. This program focuses on working with community members, building trust by bringing food and pet supplies into under-served communities, and progressing to providing vaccination, spay/neuter, and training services. It is an inspiring program, but I have found no peer reviewed publications about it. This is the sort of thing I'd like to see a case study on in a veterinary journal. Rather than reading a glowing report about a program written by the creators of the program, I want to read an objective discussion of it by an outsider who also happens to be an expert in the area. It would be nice to be wrong about this (except for that naturally it would be a little embarrassing), but I have been unable to find any such publications in veterinary journals.

And there are more and more such efforts out there, programs to address canine and feline obesity, to help build fences for yards to help owners stop chaining up their dogs. I’ve been calling such initiatives “community-based public health,” and I want to know more about them from experts. Randomized controlled trials are going to be impractical if not impossible in these situations, but I want case studies!

...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.